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Share a proven position

Every proven position has a page of its own with a picture of the position, so a link to it shows the board. A button copies the link. The page says whose move it is and what to find, never the move.

The rule language on a page of its own

The description of the rule language is now a readable page, with a link on every heading so you can point someone at exactly the part they need. The landing page and the designer link to it.

Set how long pieces rest in the designer

One choice beside adding a piece sets how long every piece waits after it moves, and each piece's card can set its own. The designer says in words what each piece rests.

The designer counts in rounds

In a game played in rounds, the designer now counts the longest a game may run and the opening choices in rounds, and the rule itself is called playing in rounds.

Every rule easy to find in the designer

Each piece's card now says how it takes its turns: its speed, what it beats and whether it is a spy in a game played in rounds, and how long it rests in any game. You can find any rule by typing a word such as rounds, atomic or walls.

Proven positions for more games, kept up to date

When a game joins the library, its proven positions are now found and proved by themselves. Makruk offers its first, and the rest of the library is being worked through.

Badges for proven positions

Win every proven position on a game against the hardest computer player and you keep a badge for it. Do that on 5, 10 and 25 games for three more. They stay yours even when more positions are proved later.

A page for each game's proven positions

Each game's proven positions now have a page of their own: the board beside the list, ticks on the ones you have solved, how much of the game you have done, and previous and next, so you can work through them without leaving. Your profile shows how much of all of them you have solved.

Rest for each kind of piece, and a stronger opponent in rounds

How long a piece must wait after it moves is now set for each kind of piece, in any game, whether players take turns or move at once. The hardest computer player in games played in rounds is much stronger. Every score was measured again for these changes: some games moved, both watering holes now end too quickly to count as viable, and courier rose.

Make a game played in rounds in one step

The designer now opens with how the players take turns: one after the other, in rounds, or more than one move a turn. Choosing rounds makes every change the game needs, lists them, and lets you undo them. When a rule can't go in a game, the designer gives every reason at once, in plain words, beside the rule it concerns.

The rules document helps you design, not only write

The published description of the rule language now opens with a map of what each family of rules is for, and adds a section on how a game that passes every check can still play badly. It also says exactly when a wild piece gives check.

Fewer, better proven positions

The proven positions no longer include the ones that are too easy, where the defender's moves change nothing; the list says how many were left out and why. A position stays only if it has exactly one winning move and the quick computer players don't find it: 21 across the seven games, 3 on Intransitive. A game where every position was too easy says so.

Scores kept from a sample say so

When the engine changes in a way that should not move any game, a score can now be confirmed by replaying a sample of its games instead of all of them. Such a score is marked as kept from a sample.

A newer computer player on Intransitive and Gardner

The learned computer player on Intransitive and on Gardner is a newer one, trained on its predecessors' games. Gardner's score moved up with it.

Links to the site show a preview

Paste a link to the site, or to any game on it, into a chat or a post and it now shows a card with the page's title, a short description and a picture. A game's card shows that game's own starting position.

Asking for an invitation reaches a person

When you ask for an invitation, the person who runs the site now gets an email about it straight away, so your request no longer waits to be noticed. The privacy notice says so.

Circe mortal diagonals

A new game to try: circe chess where a captured queen or bishop is gone for good, while a captured knight, rook or pawn is still reborn on its home square. The endless capture loops of plain circe stop, and games end in checkmate; it scores well above circe on the project's measure of how interesting a game is.

one-way torus chess leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is this project's own design, written to show the one-way seam on both axes, and the Baseline keeps to games people chose to play that were not made to show a rule.

Scores stay as they are until every game is re-scored, which happens after several such changes.

one-way cylinder chess leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is this project's own design, written to show the one-way seam, and the Baseline keeps to games people chose to play that were not made to show a rule.

Scores stay as they are until every game is re-scored, which happens after several such changes.

sardines leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is one cell of a family this project generated to isolate a rule, and the Baseline keeps to games people chose to play that were not made to show a rule.

Scores stay as they are until every game is re-scored, which happens after several such changes.

torus crazyhouse leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is this project's own design, and the Baseline keeps to games people chose to play.

Scores stay as they are until every game is re-scored, which happens after several such changes.

rear guard torus chess leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is this project's own design, and the Baseline keeps to games people chose to play.

Scores stay as they are until every game is re-scored, which happens after several such changes.

chess with turning pawns leaves the Baseline for the Library

It stays in the library with its score, and no longer sets the scale the other games are measured against.

The reason given: Moved to the Library: it is the showcase written for pawns that face a direction, and the Baseline keeps to games people chose to play that were not made to show a rule.

Scores stay as they are until every game is re-scored, which happens after several such changes.

A new map of the games

The map of games is redrawn from scratch. Games now sit near the games they share their rarer rules with, families are found and named automatically from what marks them out, each game lists the five most like it and what they share, and the unusual games are listed on their own. Adding a game no longer reshuffles the map. A game's own page lists the same games like it as the map does, in the same order.

The computer varies its play from game to game

Every game on the site used to start from the same random seed, so in a given position the computer always answered the same way. Each game now starts from its own seed, and a finished game still replays exactly.

The watering hole, easier to read

The white elephant, camel and wazir were drawn see-through, so the board showed through them; they are filled white now. Both watering hole games, and the round versions of Gardner's minichess, now say first how you win.

Every game has its own address

Each game now lives at its own web address, and the page carries the game's name, description, score and nearby games even before any script runs. A link to a game shared anywhere now names that game, and older links still open the right one. Search engines are now welcome: the site lists its games for them, and every page says what it is.

The board alone, full screen, on a phone

On a phone or tablet, the play page now has a full screen button: the board alone fills the screen, upright or on its side, with the side to move and the result still in view. Turning the phone keeps the game where it was, and the back gesture returns to the page.

Proven positions are back on their games' pages

Since 16 October the site had quietly lost track of some of its stored files: the proven positions, the ladders of computer players for a few games made here, and designs members saved in that time. They are all restored. The filter for games with proven positions now finds the seven that have them. Six of the project's own early designs are now listed in the library, each with a sentence on why.

Find the games with proven positions

The games list can now be narrowed to games that have proven positions to solve: open narrow it down and choose has some to solve. Seven games have them today. The watering hole by speed has also joined the library as a full game, with a ladder of computer players to play against.

Speed: in games played in rounds, faster pieces move first

In a game where both players move at once, pieces can now have a speed. When two moves meet in a round, the faster piece's move happens first, and the slower move may find its target already gone, or its own piece already taken. The page shows the order: the faster move plays, then the slower one. Three new games show it. The watering hole by speed, where cat, rat, dog and elephant race to the water and arriving first matters as much as who eats whom, measured as a real game, with every game decided at the hole. Two versions of gardner in rounds, one with a swift king and one with swift knights, are offered as previews: both turned out drawish, and in the knights' version strong players trade the two fast knights on the first move.

Proven positions: endgames the computer has proved are won

Seven games' pages now have a Proven positions section: endgames taken from the computer's own games, each one proved won for the side to move by a deep search. If you are signed in, you can play one out against the hardest computer player, and the game's own ending says whether you converted it. Where only one move wins, anyone can try to find that move, and the answer comes from the stored proof; a move the search could not settle is said to be unsettled, never wrong. There is no timer and nothing to keep up: a miss is just a game you lost, and the positions you have solved show on your own page, for you alone. About eight hundred positions are on offer across the seven games.

One fewer preview

Gardner in rounds resting leaves the previews. It turned out to be breather with two of its rules taken away, and it played the same way, so it offered nothing breather doesn't. Its page and games are kept. The one preview left is gardner with spies resting.

Circe now follows the real Circe rule

In circe, a captured piece comes back to life on one of its starting squares. A captured rook, knight or bishop now returns to the starting square of the same colour as the square it was taken on, as in the published game, so a bishop always keeps its colour. Before, it went back to the starting square on the same file, which differed for captures on six of the eight files. The game was measured again under the corrected rule and now counts as a playable game, where before it fell just short.

Every game says what it is about

Sixty-six games have new descriptions. Most used to be a list of rules, which the page already prints beside them, or explained a game by comparing it with another game in the library that a visitor had no reason to know. Each one now says what the game is exploring and the choice it keeps putting to you: in a game where a capture upgrades the piece it strikes, whose gift is each exchange; in a game with a door either side may move, whether to move the army or the road. Terms from other variants and from shogi are explained where they appear, and where a game is a published or traditional one, it says so. No game plays any differently. While checking every rule the old texts stated, a few turned out to be loosely put (a pawn that can turn may face any way in one move, not only a quarter turn; two games with one-way edges are not exactly fair), and the new descriptions say what the games really do.

The Gardner game where both players move at once is now called *breather*

Its old name and description explained it by contrast with an earlier experiment most people never saw. Now the description says what the game is: both players pick a move in secret and move together, a piece that has just moved must sit out the next round, and you win by taking the king. Nothing about how it plays has changed, and its score and computer opponents are the same. Several other games' descriptions were reworded the same way, so each one reads on its own.

Fewer previews, and the ones left are worth a look

Six preview games are leaving the Previews tab. Each was made to show off a new rule, and each ended up mostly drawn or leaning heavily to whoever moved first, so they made poor games. Two stay: gardner in rounds resting, which plays evenly and is decided most of the time, and gardner with spies resting, the one game that shows the spy.

Riders and leapers joins the library

Riders and leapers moves from the previews into the library, with a score and computer opponents of its own. It is a game with no king and two different armies: one side has rooks, bishops and guards, the other champions, knights and elephants, and a side loses the moment any one of its own three kinds of piece is gone, which no other game in the library asks. A pawn that reaches the far rank can bring back a kind that is about to run out, so every trade is a question of which kind it leaves short. It is played on a six by six board and its games are short and sharp.

Games with spies against another person

A game with spies can now be played against another person, each of you moving when you like. While both spies stand you take turns, as in any game. Once a spy is lost, its player replies with one move, and then each round the player without a spy announces a move first, which both of you see on the board, and the spy's holder answers it before both moves are made at once. Once both spies are lost, each of you seals a move in secret, as in the other games played in rounds. If you switched on move emails, each one says what is asked of you: your reply, your announcement, your answer to the move announced, or your sealed move.

Stronger computer opponents in games played in rounds

In a game where both players move at once, easy, medium and hard now weigh sixteen times as many rounds before each move as they did, so each of them looks past the round in front of it. Before, easy played exactly like greedy, and hard came out weaker than medium on both such games in the library. The strongest still answers in well under a second, the three are rated afresh on each game, and without an account you can still play every one of them up to hard.

How often the computer played the same game again

Each game's page now says how many of the games behind its score were different games. On a few small boards the computer players play some games over again, move for move, and where that is enough to move the score, the page says the score rests on repeated games and gives the figure counted once. The test that rules out a game won by one side now counts each different game once too, so Gardner with spies and Gardner with spies resting are no longer ruled out for it: their strongest players won nearly every game from the first side, but those games were a handful played over and over. No score changed.

Computer players guard their spy

In a game with spies, the computer players now count holding the only spy as worth a piece, so they guard their own, hunt the other side's and no longer trade it for a pawn. Every game without a spy plays exactly as before.

Two games played in rounds join the library

The watering hole and Gardner in rounds against the chase move from the previews into the library, with scores and computer opponents of their own. They are the first games in the library where both players move at once.

Two previews with spies

Gardner with spies and Gardner with spies resting put a spy on each side of Gardner's small board. While a side's spy stands, the other side announces its move before both move at once. Both are previews for practice: in the first, the spies are traded away early and the rest is a draw; in the second, where a piece that moved must rest, the spy matters, but the first player still wins too often for the game to be scored as fair.

Games with a spy can be scored

A game with a spy can now be given a score like any other game: the computer players play it through every phase, and the measurements read each turn and each round by what the players knew when they chose, including a round in which one player saw the other's move first. A spy game's score also says how often a spy was lost, how early, how, and how long each phase of the game lasted. The automatic game designer can now try spy games too. No game in the library has a spy yet.

Games with a spy can be played on the board

A game with a spy can now be played against the computer, or by two people at one screen, from its first move to its end. While both spies stand, the players take turns. Once one is lost, play goes to rounds: the player without a spy shows their move first, drawn on the board as a solid arrow, and the other answers knowing it, then both moves are made at once. Once both are lost, both players choose in secret. The line above the board says which of these the game is in. No game in the library has a spy yet; one you build with a spy can be tried on the designer's board. Games between two people at their own screens do not take a spy yet.

Four new previews: a royal chase in rounds, and its cures

In Gardner's small board played in rounds, a king could be chased round the board for the whole game. Four new previews try the cures. When a piece that moved must rest the next round, the chase all but ends and most games are decided; with all three new rules together, Gardner in rounds against the chase, nearly every game is decided and its score is read as a good game.

Resting pieces and collisions are drawn on the board

In a game where a piece that moved must rest the next round, a resting piece now wears a pause sign. When two pieces try to swap squares and collide, a burst is drawn between their squares, and the replay shows them meeting half-way. When both royal pieces fall in the same round, a sentence says who won and why. The computer players also stop walking a resting king onto a square an enemy piece can still reach next round.

New rules for games where both players move at once, and for losing a kind of piece

The rule language has four new choices. In a game where both players move at once, a piece that moved can be made to rest for the next round; two pieces that try to swap squares can be made to collide, so both are lost; and when both players reach an ending in the same round, the one ahead on the score can be made the winner instead of calling it a draw. These answer a royal piece being chased round the board for the whole game. Separately, a game whose two armies are made of different pieces can now make a side lose as soon as any one of its own kinds runs out.

A spy piece, which sees what the other side plans, is in the rule language too, but no computer player or board plays it yet; those come next.

Stronger computer players measure the games where both players move at once

In a game where both players move at once, the weakest computer players used to search so little that they made the same move as the simplest player every round, so the ladder of opponents looked flatter than it is. Every rung now searches sixteen times as far. The watering hole's score rose from 0.50 to 0.61, because its players now separate clearly. Gardner in rounds shows no score for now: its games end in a draw so often that two of its four measurements cannot be read.

Standoffs in a round game have their own colours

In a game where both players move at once, the board marks two kinds of standoff: a round in which nothing happened, and a pair of moves barred from being repeated. Both were drawn in the same dark green as a move you have picked but not yet sent, so the three were easy to confuse. A standoff after an empty round is now an umber dashed link, a barred pair a blue barred link, and your own picked move keeps its green, in light and dark themes.

Play a game in rounds against a friend, a round at a time

A game where both players move at once can now be played against another member by correspondence, like any other game between two people. Each round you choose your move and seal it; your opponent sees only that your move is in, never which, until theirs is in too, and then both are made at once. A sealed move is final, so the board lets you change your mind until you press Seal my move. If you switched on move emails, you get one when your opponent's move is in and one telling you how each round went. Each round has five days: whoever has not sealed by then loses, and if neither of you has, the game is drawn.

Previews: four games where both players move at once

The games page has a new tab, Previews, with four games played in rounds: three versions of Gardner's five by five minichess, and the watering hole, a new game on a seven by seven board where elephants, cats, dogs and rats race for the water hole in the middle and every animal eats exactly one kind of the other side's. The watering hole is the one we think plays best. Each carries a Preview label: a new kind of game, still being tested. You can play any of them against the computer, at five strengths, or watch two computer players. For now every game on a preview is practice: previews have no leaderboard, are kept out of the library's rankings and comparisons, and their scores are a first reading, not yet trusted.

Games where both players move at once

A game can now be played in rounds: both players choose a move in secret, the two moves are revealed together, and then both are made. When two pieces land on the same square, the game's own table decides which survives, or whether both are lost. The play page shows both moves arriving together, explains each clash, and marks a capture that has been barred for repeating. The computer opponent chooses its move without seeing yours, and two people can also play at one screen. You can try it from the designer by turning on both players move at once, or play the four previews below.

The rules guide matches what the site accepts

The rules guide and the designer no longer say a piece may move in at most eight directions, or that every piece needs a move of its own. Neither was ever enforced when a game was checked, and some games in the library already go beyond both. A piece that only ever enters the board from the hand may now be written with no moves at all.

The learned player on the leaderboard

On Intransitive, racing kings, gardner, king of the hill and rps-v2, the learned player is no longer an experimental practice opponent: you can play it for rating, and it has its own place on the game's one leaderboard, beside people and the other computer players. On Intransitive and racing kings it is now the strongest player there. Earlier games against it stay as practice.

Five games measured by their learned players

Where a game has a trained computer player that has proved itself, that player now does the measuring in place of the ordinary one. Five games were measured again this way. Racing kings changed most: with players that understand it, it now passes as a proper game where before it was ruled out. The other four moved only a little. Each score keeps its earlier value in its history.

The rules guide, current and versioned

The designer's link to the rule language now opens the site's own copy, which always matches the rules the site checks, and its first line says which version of the language it describes. A game written from it, by hand or with your own AI, declares that version. The public copy of the code is now refreshed with every update to the site, so it stays in step too.

Stronger learned opponents

Racing kings now has a learned computer opponent, trained on the game itself, and its second generation is much stronger still: it wins about nineteen games in twenty against the ordinary hardest opponent. In rps-v2 the learned opponent has been replaced by a newer generation that beats the old one, and wins nearly two games in three against the ordinary hard opponent. Both are offered as the experimental learned player.

A plainer note when a score rests on fewer runs

When the computer players could not be told apart by strength on one of a game's measuring runs, that run gives no score, so the whole score rests on the others. The note under such a score now says so ("the score rests on 3 runs alone") instead of "parts of the score".

A quicker start for the library

When the site restarts, including straight after an update, the library and the front page now appear in a few seconds rather than about a minute.

Rated opponents for the new games

Pinwheel, Pitchfork, Sluice, Crease, Pawnproof Wormhole, rear guard torus chess and torus crazyhouse now have rated computer opponents, so each one has a leaderboard. Every game in the library now does. In Perpetual, Fairy-Stockfish has joined the leaderboard too.

Quarry's walls, the same on both sides

In Quarry, a wall beside a piece used to stop its diagonal step on one side but not on the other. A king or pawn next to a wall can now step diagonally past it either way. Quarry's score barely moved.

Play Perpetual against Fairy-Stockfish

Fairy-Stockfish can now be your opponent in Perpetual, the chess variant with no draw by repetition. And a new game whose portal rule against going straight back could never take effect is now turned away, with a sentence saying why; games already saved with one still load and play as before.

Three new portal games

Sluice is chess with a funnel of portals for each side, several ways in leading to one way out. Crease is Capablanca chess with two pairs of folds that the players can move, and a piece that lands on a fold may stay or come out on the far side. Pawnproof wormhole is Wormhole with pawns kept out of the tunnel, which takes away the first player's head start.

Fairer scores for portal and turning games

Two things the scores counted were wrong. A portal was being counted as one of a player's pieces that never moved, which made portal games look as if their armies sat idle, and a piece turning on the spot was being counted as a capture on offer. Every game has been measured again. Seven portal games score higher (carousel from 0.771 to 0.804), and no game's verdict changed.

Pitchfork

A new game: chess with eight wolves circling the centre, and only a pawn can bring one down. The wolves walk in pairs, nose to tail, so a pawn that takes the leading wolf is usually eaten by the one behind it. It replaces wolves immune, which played the same as the plain wolves game.

Pawns that face backwards

A piece can now be set facing one way for good, so that no move turns it round. In rear guard torus chess and torus crazyhouse the rear pawns are now ordinary pawns placed facing backwards, and every pawn is drawn pointing the way it walks, for both players. When you design a game, the pawn's card has a setting for whether it may turn.

Pinwheel, and clearer names

A new hexagonal game, Pinwheel, replaces four variants of Glinski's hexagonal chess. Its knights are one-handed: each reaches only six of the twelve cells a hexagonal knight could, all turning the same way, and the board's two empty flanks are joined, one way for each player. Nineteen games have new names that say what they are, such as gift chess, wolf hunt, steady ferry and glinski hexagonal chess.

Folds, revised

In games with fold portals, a piece that ends its move on a fold now chooses: stay there, or come out at the linked fold, capturing anything standing there. Pieces no longer reach out of a fold they stand in, and a sliding piece no longer carries on through one.

Folds on the board

The far end of a fold no longer shows a ghost piece. Staying on a fold or going through it is an ordinary dot to tap. And if you have a piece picked up and tap a portal you could also move, the page now asks whether you mean to move the piece or the portal, instead of making the move.

A tidier library

The library had several games that were near copies of each other, differing in a detail that barely changed how they play. Fourteen of them are gone, leaving 87 games, and 29 games have new descriptions that say what their difference does on the board.

Offer a draw

Playing the computer, you can now offer a draw once the game is under way. The computer answers at once: it asks its strongest player how the position stands and accepts only if neither side is clearly ahead. Between two people, the other player can accept or decline. A draw by agreement counts as a draw on the leaderboard.

A saved design can be given a description later

Saving a design again with a new name or description now keeps the new words, and the page says so, instead of answering that it was already saved. A published game keeps the words it was published with.

Under games near this one, a piece the two games call by different names is now named both ways, so the sentence no longer names a piece the other game doesn't have.

On a wide screen the map of games lists its communities once, with folding in each community's own panel, so the map starts higher. On a phone, the designer's bar for a game that plays is a single row of buttons.

The chancellor and the archbishop look like themselves

The chancellor, which moves as a rook or a knight, was easy to mistake for a knight. It is now drawn as a rook's tower with a knight's head rising from its battlements, and the archbishop, which moves as a bishop or a knight, as a bishop with a small knight's head.

Two more versions of Divide

Divide's door was tried two other ways: open in both directions, and fixed in place. Both are in the library beside the original, with their scores and rated computer players. Neither plays better: strong players still mostly draw, and a much deeper search did not change that, so the walled board itself is what holds the game level. The original stays Divide.

Two wolves on one patrol

A wild piece's walk can now carry more than one piece: in the designer's wild pieces card, more on this walk adds another start on the same route, and the pieces on one walk step in turn, the front one first. The library has a new game made this way, wolves patrol: two wolves circle the middle of the board, one starting from each end of their loop. It has a leaderboard and rated computer players, like every library game.

The designer explains wild pieces better

Picking a piece from the tray that is also a wild piece in your game now says so, and points to the wild pieces card where its walk is set. Two walks that cross are refused in one sentence naming both, with the way to put a second piece on the same walk. The wild pieces card has one short introduction, and add one starts with the piece you added last.

A wild piece's walk is now drawn on the board: coloured arrows show the way it goes, a jump between squares that do not touch is dashed and named under the board, and several pieces on one walk share one path. The designer draws it too, even while a draft is not yet a game.

Picking a walk in the designer is quicker: the board stays in view, each square shows as you click it, and a whole row or column joins on from the end nearer the square you picked last, so a loop takes a few presses. A new + wild piece button under the pieces puts a wild piece straight onto the board and starts its walk there.

A design too big to save says so

Saving or loading a design over the 64 KB limit now shows the site's message saying so, instead of a request that fails without a reason.

Portals in rings, funnels and folds

A rule file can now link portals in more ways than pairs: a ring that passes a piece on round a loop, several portals leading into one, and portals only some kinds of piece may use. A portal's description says by square where it leads and which pieces may go in. There is also a second kind, the fold: a portal a piece can stand in, move out of from either end, and slide straight through. Every existing game plays exactly as before.

On the board, each portal now has a small beak on its rim pointing to where a piece comes out, and a portal map button draws the arrows between them. A portal only some pieces may use has dashed arms and dims when you pick a piece it turns away. The designer's + portals places a pair, a ring or a funnel, with a leads to choice for each end and a choice of which pieces may go in. On a phone, a portal's arms are easier to tell apart.

A fold looks like a bright pool lying in the board: a piece standing in it shows faintly at the far end too, and a piece passing through sends a ripple across. The designer asks how each group of portals works, by momentum or as a fold, and its preview shows the moves that go through a fold.

Portals easier to read

A first reading of the new portals showed one place people went wrong: a portal nobody can move looked as if it stood on a token. Such a portal is now drawn as a hole in the board, a portal nobody may enter has no arms and stays still, and the legend's (i) teaches the look in two rows: what a portal stands on (who may move it), and its arms (whose pieces may go in).

A member's game is rated as soon as it is published

Publish a game and, within a few minutes, its five standard computer players are rated against each other: rated games and the game's leaderboard are open from the start, and the stronger computer players join once they have been rated too. A game too slow to rate quickly says so, and waits to be rated by the project's own machine.

Portals, redrawn

Portals have a new look. Each pair has its own colour, the same at both ends, so you can see which portal leads where; games with several pairs show each in a different colour, with its number. Inside each portal, slowly turning arms show whose pieces may go in, and a portal either side may move stands on a white or black token, while one nobody can move is sunk into the board. Moves and messages now name a portal by its number and square, the legend's (i) shows four examples, and the designer builds pairs the same way: click a square for the first end, then another for the second.

Write a game by hand, or with your own AI

The rule language every game is written in is now described in full, with worked examples, in a page in the project's public code. The designer links to it and has a load a rule file button: write a game as a file, load it, and it becomes your draft. A file with a mistake is refused with the same explanation the designer gives, and your current draft is left as it was.

Pieces travel through portals

A piece moving through a portal now makes the trip on the board: it slides to the portal, spins down into it, and spins up out of the other end with a springy landing. Stepping forward through a finished game shows it too. If your device asks for reduced motion, the move is a short fade instead.

Ask for an invitation

Accounts are still by invitation, but you no longer need to know a member to get one. The sign-in page has a Request an invitation button: leave your email address and, if you like, a note on how you found the site, and an invitation is sent if the request is granted.

Each game has a leaderboard

A game's page now shows one leaderboard: its computer players and everyone who has finished a rated game on it, strongest first. A number still settling over someone's first games carries a question mark, your own row is marked, and a game nobody has played yet says so plainly.

Portal games say when only a portal can move

In check on a portal game where your only way out is to move a portal, tapping one of your pieces now says so and names the portals to tap, instead of only saying that piece has no legal move.

Portal moves: choosing the way is readable again

When a piece can reach a square two ways, directly or through a portal, the box asking which way now shows the piece and names each route in ordinary text. Before, the route's words were squeezed into the piece's picture and spilled across the box.

Every game in the library has rated computer opponents

The 29 newest games in the library had no rated computer players, so they offered only casual play against the computer. All of them now do: every game in the library can be played for a rating against computer players of known strength. The computer players on every game were rated again the same evening by today's players, each game's table centred on the same five standard computer players.

New games stay marked as new, and the games list sorts by date

The front page's new in the library shelf now follows the day each game joined, so a game added tomorrow appears there with no one updating a list, and it lets go of a game after two weeks. Every game now carries the day it was added, and the games list can be ordered newest first, each card saying its day.

Smaller fixes from watching people's first visits

A resign or cancel button now waits fifteen seconds for its second press, so there is time to read really resign?. On a phone, tapping a tag on a game's card says what the tag means instead of opening the game; the cards on the front page open from anywhere on them; a list with no scored games opens in name order rather than by score; and the games list is ready about a third sooner after the site restarts. In the designer, picking a piece no longer makes the board jump, teach a move names its squares, and a tall board in a game between two people now fits on a phone's first screen.

Ferry without the shuffle

In Ferry, two in five games ended in a repetition, nearly all of them by a player moving a portal straight back to where it had just been. A twin game, Ferry no straight back, forbids exactly that, the way Go forbids retaking a ko at once: repetitions fall to fewer than one game in ten, and it scores higher than Ferry. In the designer, a portal pair's card has a Not straight back tick for this.

Make your own portal games

The designer has a portal row in its tray: put down a pair, move either end, renumber or remove it, and choose who may move each end. Each pair has a card that says in plain sentences what it does, and when you teach a piece a move the board shows where it would come out of a portal before you try it. To start from one that works, open Divide, Ferry or Carousel and choose make your own from this.

Portals, and seven games that use them

A board can now hold pairs of portals: a piece that steps into one comes out of the other and carries on in the same direction, and a square it can reach two ways asks which way you meant. Seven new games in the library use them. In Divide a wall splits the board and the portals are the only way across; in Ferry either player may move the portals themselves; in Carousel some doors open for one side only. Four small games each try one idea on a little board, and two of those are marked not viable: there, the player who moves first gets through the door first and almost always wins.

Hex moves you write once and turn

In the designer, a piece's move on a hexagonal board can now be written once and turned all six ways, or turned and mirrored, instead of listing every direction by hand. Two new archive games are Gliński's hexagonal chess written this way; they play exactly like it.

Jeson Mor, where you win by leaving the centre

A game can now be won by moving a piece off a square. In Jeson Mor, each side has nine knights, and the first to land a knight on the centre square and then step off it again wins. It is in the library with a score of 0.70, below the bar the library sets for a good game.

Kyoto shogi, where a piece in hand can come back as either of its faces

Kyoto shogi is in the library with a score. Its pieces turn over every time they move, and a captured piece can be put back on the board as either of its two faces: the board page now shows one button for each face when you hold such a piece.

Two games that start with pieces in hand: Placement chess and Sittuyin

In Placement chess and Sittuyin (Burmese chess), the pieces other than the pawns begin off the board, the king among them, and the game opens with each side placing them one at a time. Both are in the library with scores.

Two more games: Extinction chess and Grand chess

Extinction chess, where you lose when any one kind of your pieces is gone, and Grand chess, where a pawn may only promote to a piece you have already lost, now play by their real rules and are in the library with scores.

Two new games: Einstein chess and Omega chess

The rule language can now say two things it could not: a piece that captures may stay what it is instead of changing (Einstein chess, where a queen that takes stays a queen), and castling may happen on a row that has walls beyond the rooks (Omega chess). Both games are in the library with scores.

The map's settings and the designer's checkboxes are back in place

On a wide screen the map's settings fit on one line again, so the drawing starts on the first screen instead of below it. In the designer, the royal box sits beside its word again. On a phone, a ticked line under Publish that wraps now lines up under its own words.

Scores for the three newest games

Pawn Knockdown, Shogi Backward Drops and Shogi Drop Promoted now have scores, each the average of four measurements.

A game whose computer players could be told apart only some of the time now says so

Each library game is measured four times. Where the stronger computer players beat the weaker ones clearly in only some of those measurements, the game's page now says in how many, instead of calling them steadily stronger. How far the score is trusted does not change.

The designer explains a draft that isn't a game yet

When you ask the designer what a piece can do in a draft that is not yet a complete game, it now says what is missing in a plain sentence instead of failing with a server error.

Plainer words when measuring stops, and the board's tabs first on a phone

When measuring a game in your browser stops before it finishes, the page now says so in plain words instead of showing a programming error. Game pages no longer show the technical names another chess program uses for pieces and rules, and on a phone the board page's moves, rules and pieces tabs now come before the players' lines instead of under them.

New games and Intransitive on the front page; the games page goes straight to the list

The front page now shows the games added to the library most recently, each with the day it was added and its score, or a plain not measured where the computer players have not measured it yet. Below them, Intransitive, the rock, paper, scissors strategy game, has a place of its own, beside today's game and this month's game, which used to sit at the top of the games page. The games page now opens straight on the search and the filters, with every game in the list, instead of repeating the front page's picks above a folded All games.

The game builder and the map in the site's look

The game builder and the map now look like the rest of the site. In the builder, each piece is its own sheet of paper, the one you are editing is edged in green, and the rules are rows separated by thin lines instead of boxes inside a box. On the map, the settings above the drawing sit on one sheet. On a phone that sheet folds to a single line, so the map is the first thing you see, and one tap opens the settings.

Where the computer players stand among people

On a game where at least five people have a settled rating, the line about its strongest computer player now says, under more, where each computer player people have played sits among them: about which rating a person would need to play like it, and how many of the people with a settled rating it is above. It comes from rated games people played against it, and it changes no game's score.

Placing a captured piece, right on the board

In games where taking a piece throws it onto a square of your choosing, the choice of square now appears in a box over the board, as choosing a new piece for a pawn does: each square a large button named as on the board's edge, with Look at the board and Cancel. When your pawn takes on the far side, the box first asks what the pawn becomes, with each piece drawn and named, then where the piece you took goes. Before, both were a row of small buttons under the board that named the new piece by a single letter.

The wolves show both of their next steps

In games with pieces that belong to nobody and walk on their own, like the wolves, each one takes two steps before it is your move again: one after your move and one after your opponent's. The board now shows both. The dotted arrow is where it goes after the next move, and a fainter dotted arrow carries on from there to where it goes after the move after that. The line under the board says which is which, in a game against the computer, in a game against another person and when you step back through a game.

Finding other players

Members now have People at the top of every page. It opens a list of every member, A to Z, with a search box: type a few letters of a name, or of a game somebody made, and press a name to open that member's page. A member's page shows the games they made, newest first, the games they played lately, their milestones and badges, and says plainly what there is nothing of yet. Challenge on their page now offers the games they made first, and starts a correspondence game when they accept. Names elsewhere on the site, on a game's page and on your own page, now open that person's page too.

Choosing what your pawn becomes, right on the board

When your pawn reaches the far side, the board now darkens and a box over it asks Choose what your pawn becomes, with each piece drawn large; tap one, press Look at the board to see the whole position first (the move waits until you choose), or press Cancel. Before, the choice was a row of small buttons under the board that was easy to miss.

Members' games on the front page show their own pieces

The small boards under Made by members on the front page showed every piece as a letter in a circle the first time you opened the page. They now show each game's own pieces, the same drawings as on the games page and the game's own page, including pieces a member drew themselves.

A bigger board in a game against another person

In a game against another member, a tall board (torus chess crazyhouse, say) used to sit at half the width it had room for, with Send your move and Change my move squeezed under it, Change my move cut to a few letters. On a wide screen those buttons now stand beside the board when that leaves the board more room, so a tall board is about half as wide again. On a phone they take the whole width and wrap their words rather than cut them off. The board no longer shrinks by a few pixels the first time you pick a move.

Publishing a game no longer waits for the site's check

When you build a game, the button that measures it on your computer is now right beside Publish, under the line that says a score is needed, so there is no scrolling away and back. Once your computer has finished measuring, Publish works straight away: press it and the page says publishing will be complete once the site has checked the score. You can leave then. The game goes on trial by itself when the check passes, a few minutes later. If the check finds a problem, nothing is published and the page says why.

Games made by members, on the front page

The front page now has a shelf of its own for games members have designed and published here, straight under the opening board: the four published most recently, each with its opening position, the name of the member who made it and a Play button, and a link to the rest when there are more. Drafts are never on it. Until somebody publishes a game, the shelf says it is empty and invites you to build one. The opening board also now says which of its games is today's game.

Changing your mind about a move before you send it

In a game against another person, a move you have picked but not sent can now be changed as easily as it was picked. Tap another square the same piece can reach and the move goes there instead; tap a different piece of yours to pick that one; tap the picked piece or the square it would land on to take the move back. Beside Send your move there is now a Change my move button that does the same (at a keyboard, so does the Escape key), and the words above and under the board say the move can be changed until you send it. Nothing reaches the other player until you press Send your move.

A move you have picked but not sent is plain to see

In a game against another person, the move you pick now shows on the board itself: the piece stands faded on the square it would go to, with a dashed arrow and dashed outlines, while the other player's last move keeps its usual yellow shading. Under the board a large Send your move button sits in a dashed box that says the other player has not seen your move yet; nothing reaches them until you press it, and put it back lets you choose again. If you leave the page first, the browser asks before you go, and the move is still waiting on the board when you come back on the same device. On your list of games waiting on your move, such a game says Not sent yet.

Inviting a friend to play, from the game itself

Under Play a person on a game's page there is now a place for a friend who isn't a member yet. If the person who runs the site has given you invitations, type your friend's email address there and they get an invitation from you; once they have joined, challenge them on the same page. If you have none, it says so and who to ask. The button at the top right, which used to look like just your name, now reads your page and looks like a button you can press.

A score is an estimate that keeps improving

Every score on the site is now treated as the best estimate we can make today, not a final verdict. When the computer players get stronger or the way a game is measured improves, the games are measured again on their own, one at a time, and each score moves to its new value. While a game waits its turn it keeps its last score, marked provisional. The yardstick a score is read against no longer shifts when a game joins or leaves the reference set, so a score moves because something about its own game was learned, not because the list around it changed.

Games you make can be published

A game you design can now go on trial, where others can find it, play it and vote on it. Measure it on your own computer from the designer: the site then checks that every game follows the rules, replays a sample of them exactly, and once that spot check passes, a few minutes later, Publish opens. Until then the game stays a draft that anybody with its link can open. A score whose replayed games come out differently is not kept, and the account cannot publish until the person who runs the site has looked at it.

The board holds still

On a phone, the board no longer jumps up and down while you play. The line above it, which says whose move it is, in check, thinking or the result, now keeps the same room whatever it says. A move that could not be made is explained in a message at the foot of the screen rather than above the board.

The front page for everyone, and the games at their own address

The front page that says what this is now greets everybody, signed in or not. The games have an address of their own, /game: Games at the top of every page and games at the foot go there, and so does signing in or accepting an invitation. The name at the top goes back to the front page. Links you already have, to a game, to a game in progress or from an email, still open what they named. On the front page, a member sees Your page where a visitor sees Sign in.

A way to get in touch

The front page and the foot of every page now say how to reach the person who makes and runs the site: a link to their GitHub page. The terms name the same place for asking to take something down.

The terms, and what publishing a game gives away

The site now has terms, linked at the foot of every page. Games made here are for everybody: when you publish one, you give its rules, name and description to the public domain (CC0 1.0), so anyone may copy, change, share or sell it, and the site keeps nothing and claims no credit. Publish shows that sentence beside a box to tick first. Each point on the terms page is in plain words, with the legal wording beside it.

A front page that says what this is

The site now opens on a page of its own before the games: a quiet board showing some of the games in turn, then what the site is for, how games are built from a palette of rules, playing the computer and other people, how the computer checks that a game works, and what the score is: a best estimate that keeps improving, not a final judgement. What goes into the score opens to show every ingredient, why it counts, how it is worked out and how much it weighs. See the games is one tap away, and members go straight to the games; the page is always at about in the footer.

No password box before the site

The site no longer asks for a shared password in a browser box before it opens. Anybody with its address can look around and play practice games against the computer players up to hard; hardest is for people with an account, and the opponent list says sign in to play beside it. An invitation's link now goes straight to choosing a handle and a password.

Invite somebody

If you have invitations to send, your profile now has Invite somebody: how many you have left, and a box for the address. The person gets the usual invitation email, naming you.

The designer keeps out of its own way

When a change makes your game not a game yet, the note at the foot of a phone's screen is now one line with the first thing to fix, and the full list is one tap away, so it no longer covers the setting you are fixing. On a computer, the mouse wheel over the right-hand column scrolls the page again. Start from a template or a copy of a library game now sits above the board; each way of moving you type is read back in words under it; and the verdict says when it was last checked.

A gentle first game, with the rules at hand

The first time you start a game on a game's page, it seats the gentlest computer player on that game (marked gentlest among the opponents), as a practice game, and the board opens with the rules beside it; a harder one is a tap away. While you play, tapping one of your pieces shows how it moves in a line under the board. On a game far from chess (no royal piece, won by reaching a square, or with wild pieces) the page also offers to watch two computer players first.

Each piece on a board of its own

Under The pieces on a game's page, each piece now has a small board showing it alone, with a dot on every square it can move to and a ring where it can take. The pieces that move like nothing in chess come first, with their boards open; a piece that moves exactly like one of chess's says so (moves like a chess knight) and keeps its board folded.

A game's page shows where the pieces start

A game's page now opens on its board: the start position drawn large at the head of the play column, before you start a game, with the squares its rules single out (a goal, a promotion band, a seam) marked and named in a line under it, and which side moves first. The list of where each piece starts is still there, folded under The rules.

Challenge a game's maker at their own game

If you designed a game that is out on trial or further, you can now switch on, on your own page, being listed on your games as taking challengers. Other members then see you first under Play a person on each of your games, as made this game and takes challengers, with a button to challenge you; you accept or decline as with any challenge, and you can switch it off at any time. It is off unless you switch it on. A win over a game's maker at their own game, in a rated game, earns a new badge, Beat the maker, once per game for each winner. A challenge carries no message.

A page for each member

Every member now has a page of their own that other signed-in members can open from the players' list, from a name in Play a person or from a seat in a game between two people: their mark and handle, when they joined, how they finish their games against people, what they have finished lately, the games they designed that are out on trial or further, their milestones and badges, and who they play most. A button on it challenges them to a game. Visitors cannot see these pages, and a draft never shows. Your own page has a new box to show the games you gave five stars; it is off unless you tick it.

Tag a game when you rate it

Beside the stars, a vote can now carry up to three of eight tags: I'd play it again, a clever rule, first player has it easy, lots of draws, goes on too long, over too fast, hard to learn and feels new. Everybody sees how many votes chose each tag, never who, and the person who designed the game sees the same counts under Your games. There is nowhere to write words with a vote, so nothing anybody types reaches a designer.

Every member has a little invader of their own

Each person here now has a mark: a small pixel creature in the family of the site's invader rook, with its own crest, eyes and legs in one of eight inks (claret, cobalt, violet, brass, walnut, petrol, olive and plum) that read on the paper in light and dark alike. It is made from your account, so it is the same every time and nobody has to upload anything. It stands beside your name in the corner and on your page, beside each person on the players' list, in a game between two people, in Play a person, on a challenge sent to you, and beside your opponent in the games waiting on you.

The site's own pages in the club room's look

The players, your own page, the maintainer's page, the privacy notice, the credits and What's new now match the rest of the site: tables and counts sit on sheets of the same paper as the cards, a page to read keeps a comfortable width with each section under a rule, What's new sets each day's entries on one sheet with the date beside it, and every page's footer is signed with the invader rook. An address with no page behind it now shows a proper page that says so, with the way back to the games, instead of a line of code.

Every game shows its board before you open it

Each game in the list now shows its starting position beside its name, on its own wood, and the card is calmer: where the game stands and its score are the two marks, and the rest is a quiet line under them. The games to start with and this month's game show their boards too. A game's page puts the play panel first, with the computer players as cards you tap (the name first, how strong it is under it), and folds the rest of the game under headings, so on a phone the page is a list of what there is to read rather than a long scroll.

How far you have got against each computer player

Signed in, a rated game's page now shows every one of its computer players in a row, weakest first, each marked with your best result against it: won, drew or not yet. A row of won is the whole ladder.

Whether people have beaten the strongest computer player

Each game's page now says, under its computer players, how the strongest one has stood up to people so far: not enough games yet, held so far once twenty rated games by five different people have not beaten it, or beaten by people once somebody has. Under more are the games and people it counts. It is read from people's own games, and it never changes the game's score or how far to trust it.

On hexagons, the designer no longer offers turns that don't fit

On a hexagonal board, a way of moving's turned menu now offers only as written: the other turns are the square board's, which a hexagonal game refuses, so every direction is listed by hand.

This month's game

The front page now names one game a month for everybody, so there are people to play it with by correspondence. October's is reckoning, a six-by-six game the computer invented here. It changes on the first of each month, taking the games to start with in turn. Playing it earns nothing extra; it is the game most people will be looking for a partner in.

The front page says what this place is

Under the day's game, three lines now say what the site is: people invent chess-like games here and anyone can play them; the computer plays each one hundreds of times and scores how interesting it is; play this one now, or build your own. Below them are nine games to start with, each with the one sentence that says how it differs from chess. The whole library, with its search, filters and order, is one click further down, under All games.

Intransitive waits longer before a draw

In Intransitive, a game now ends in a draw after 200 turns in all without a capture, 100 by each player, where it used to end after 100 in all. That is how the program on the designer's own site counts it. Long games of careful manoeuvring are no longer cut short. To the site this is a new version of the game, so it was measured again; the old score is kept in its history. The computer player that taught itself plays the new version too, after being tested on it again: against the standard computer player that looks at as many positions, it still takes about nine points in ten, as before.

A game a day on the front page

The front page now opens on one game, a different one each day and the same for everybody: cylinder chess, three-check, quarry, los alamos and crazyhouse in turn, each chess with one rule changed. It shows the board and that one rule in a sentence, with Play the computer to start a practice game against the gentlest computer player, and a harder one a tap away.

A score that is out of date says so

When a game is being measured again, its page now shows its last score marked provisional, with the day it was worked out, instead of a blank. A provisional score shows no trust word and never counts in a comparison.

How far to trust a score

Every score now says how far to trust it, in one word: early estimate when only the site's own computer players have measured the game, checked when something else agrees with them, and questioned when something has found more in the game than they see. The word sits beside the score on each card, and a game's page says it under the number with one sentence of why. Behind more is each piece of evidence: how the computer players order by strength, what an engine written elsewhere made of the game, what a computer player that taught itself found, how many people have played the strongest computer player and whether anyone has beaten it, and any earlier score, dated. People beating the strongest computer player can move the word; they never move the score.

Scores no longer depend on which reference games are chosen

The ends of the scoring scale now come from what each measurement means, not from the best and worst of a few reference games. Every game's score moved once (most rose by about a tenth), and the order of the library shuffled a little.

Play the learned player on Intransitive

You can now play the learned player on Intransitive: a computer player that taught itself the game by playing against itself, and takes about nine points in ten from the usual hard player when both think as long. It is experimental and not rated, so a game against it is practice.

Each game's card is its own sheet of paper

Each card in the library now has its own slightly different paper.

What is wrong with a draft, in plain words

When a draft isn't a game yet, the designer now says what is wrong by the names you see on the page (Where they start, row 1: z9 isn't a square on this board, Piece 2 (knight), way of moving 1: 'how far' does nothing on a leap) instead of a path into the game's text, the quick check of whether a game works speaks of sides and turns, and every field on a rule card has a plain name and a plain sentence under it.

The game designer in plain words

Building a game, the editor now says what each step costs and when it happens in everyday words (saved as your draft, happens as you edit, decided by the person who runs the site), its refusals say what to do instead of naming a file format or a fingerprint, and measuring in your browser talks about your computer's cores rather than workers.

The library and the map in plain words

The library's cards, filters and sort menu, and the map's panels, now say what they mean without the site's internal jargon: ruled out instead of cannot be won, games played by people, beaten by 3 people, not played here yet, the parts of the score by their plain names, a map that talks of likeness and the slider, and an (i) on the Baseline tag and on the line that explains the card's words.

Every page says when the site is updating

Your profile, the players, suggestions, a challenge link, signing in and joining now say in a plain sentence that the site is updating or busy, as the board does, instead of a browser's error, and a page that only reads tries once more before it says so.

See where the wolves are going

In a game with pieces nobody owns, like the wolves, the board now draws a faint dotted arrow from each one to the square it will step to after the next move, and stepping back through the game shows where they were heading then.

When the site is updating, the board says so

A move made while the site was being updated or was busy used to show a browser's error, such as The string did not match the expected pattern, until you reloaded. The board now says in a plain sentence that the site is updating or busy, puts the position back as it is, and you can make the move again in a moment without reloading.

A new look

The site has a new look: warm paper and baize green, a serif for the headings, a clearer header with a small invader-rook mark (also your browser tab's icon), and a switch for light, dark or your device's setting at the foot of every page. On a phone the sections fold behind a menu button. The pages say the same things; they now read more easily.

On a game's page, whose move it is shows as a coloured dot and in check as a red label above the board, the square names sit outside the squares, a phone gets a row of small icons with words, and a finished game shows who won across the board, with a button for a rematch and one to step back through the game.

Every board is now wood: each square is its own piece of grained maple or darker wood, in a walnut frame, and the same board looks the same every time you open it.

Play another person

Two members can now play each other, each moving when they like. A game's page lists members who said they are open to a game of it, you can challenge someone by username or send a friend a link, and a finished game offers a rematch. A move you choose waits for Send, so a slip can be taken back. If the player to move hasn't moved in five days, they lose, and every game says how long is left to move. Your page lists your games, the one closest to a loss on time first. You can switch on one email each time it becomes your move, off unless you ask.

Make your own from this

Every game's page has make your own from this right under its name, on a phone too, and the designer's start again from menu lists every game in the library. Your copy gets a new name and keeps a note of the game it came from; the original is never changed.

The designer on a hexagon

Choosing a hexagonal board in the designer now turns your game into a playable hexagon game, and the board always shows your draft's own cells instead of disappearing. On a computer a hexagon board is about one and a half times wider, and a phone is told once that building a game is easier on a computer.

Plainer sentences, and a clearer first visit

A new member's page says what to do next instead of showing zeros; the players page and the monthly round appear once they have something to show; when the strongest computer player is busy, the opponent list says so before you pick it; and the sentences that refuse something say what is true and what to do. A game's page no longer shows the project's own history notes.

The site's own pages in plain words

The badges, the milestones on your profile, the players page, the monthly round and the messages you get when a game can't start now say rated game and practice, the strongest computer player and the person who runs the site, and name a computer player instead of printing its settings. Every badge still earns exactly what it did.

A game's page in plain words

A game's page now gives each computer player one rating, the one earned on this site, and explains its score, the tests a game must pass and why a run was set aside in plain words; practice replaces sandbox, and the rules count turns rather than half-moves.

Opponents with names, and your own rating

The opponent menu now names each computer player first (hard, rated on this site, or how far above or below you it is when you're signed in), with what it does in plain words underneath, and the move list counts in the same turns. Your profile shows your own rating on each game instead of only how far you are from the top.

The explanations speak plainly

Every (i) on the site, and the panel that says how a game's score is worked out, now use plain words: the score's (i) says what the score is first, with more under more, and in-house terms are gone from them.

Clearer starts, shareable drafts

The start button now says what it starts, rated or practice and against which opponent, and remembers a rated choice. A practice game can be resigned. A designer's draft has a copy-link button and is credited to its designer by name, and the sign-in and join pages say that accounts are by invitation and that a game played without one isn't kept.

Game pages stop talking to the developer

Visitors no longer see setup instructions for a chess engine on a game page, a long code where a game's name should be, or the designer's notes about command lines and folders. The editor's trial game now says it isn't recorded, instead of calling a saved game unsaved.

Check and the end of a game are on the board

When a king is in check, its square is marked and the line above the board says so; the move list carries + for check and # for mate, and when a game ends the result appears right above the board. Tapping a piece that has no legal move now says why. The take-back, flip and resign buttons sit directly under a board that is sized to fit the screen, and the promotion zone is a labelled hatch instead of rings that were easy to misread.

Every game re-scored against today's computer players

The computer players got better at seeing threats at the end of their search on 29 September, so every game in the library was played again and re-scored. Most scores barely moved; the typical change is under a hundredth. Racing kings no longer counts as a game the computer players can measure fairly, while gardner, tunnel chess (vertical) and bastion now do. The site carries the new scores, along with the hexagonal boards and the designer's recent fixes.

Badge rules say what they mean

The rules for the badges earned by building on another game no longer say the new game must be listed; a draft that passes the site's check has always counted, and now the wording says so.

Milestones for game designers

A designer's profile now marks, with dates, their first kept draft, the first to pass the site's check, the first played by somebody else and the first another player built on. A designed game's page shows whether it passes the check, how many people have tried it, and who has built on it.

The designer's rules panel says how each piece moves

The designer's plain-English rules now include a sentence for how every piece moves, the same ones a game's own page uses. A game you watch in the designer stops thinking while its board is scrolled out of view, and a strike's chain card now starts from settings that work.

Clearer publishing and shortlist wording

The panel for publishing a draft no longer says the same thing twice, and a game's own designer is now told plainly that its reading needs refreshing, rather than being told only its designer can do it.

The designer is easier on a first visit

The two ways of playing a draft now say which is which, and the board you play on in place is wider on a phone. A piece you add says it is not on the board yet until you place it, and pressing a design step a second time now offers a new change instead of quietly undoing the last one.

Nominate a game from the designer

A designer can now put their own game forward for the shortlist from the designer itself, where it shows how far the game has come, instead of only from the game's page.

A hexagon's one-way seam shown past the board's edge

On a hexagonal board whose every pair of sides is joined, a one-way seam now carries on through the surrounding copies of the board, as it already did on a rectangle, instead of stopping at the board's outline.

Small fixes on the pages a new game climbs through

A shortlisted game's page now gives the voting round's closing date once rather than twice, and the row showing a game's level fits on one line on a phone.

A check on whether the computer plays a game well enough to score it

Each game can now be checked for whether its computer players are strong enough for its score to mean much. A game that fails keeps its score, marked with a sentence saying why, and is left out of the games that set the scale. The check has not been run over the library yet.

A monthly round decides which games join the library

Members can vote yes or no on shortlisted games on a monthly round page. The maintainer then confirms or turns each one down with a published reason. A game turned down waits 60 days before it can be put forward again.

Quiet games rest, and the measuring games say why they were chosen

A game on trial that nobody else has finished in 60 days, after 90 days on trial, leaves the listing as Resting. Its link still works, and its designer can publish it again once. A game moved into the set every score is measured against now shows when and why on its page and in What's new.

How close a game is to the shortlist

A game on trial now shows how near it is to the shortlist: days on trial, how many other people have finished a game on it, and how many votes count. Its designer gets a Nominate button that works once the bar is met, and the star panel says whether your own vote counts. No game can reach the shortlist until scores measured in the browser can be attached.

Every game says where it stands

Each game now shows one plain word for where it is on the way into the library: Draft, On trial, Shortlisted, Library or Baseline. The word is on its card, its page and the designer, the library has its own tab for games on trial, and your profile lists your games by where they stand, with the next step for each.

Games you finish are kept, move by move

Every game finished on the site, practice games included, is now kept with its whole move list, even if you undo or start again afterwards. Nothing about who played is added. This lets a win against the computer be replayed and studied, to make the computer player stronger.

A copy of an existing game is named, not published

If a draft's rules play exactly like a game already in the library or on trial, only spelled differently, the designer now says which game it copies, and publishing it is refused.

Report a game

A signed-in player can report a game as spam, offensive or a copy of another, from a small link under its rules. A report hides nothing by itself; the maintainer reviews it.

A computer player can now learn a game by playing it

A new training command has the computer play a game against itself, learn from those games which positions are good, and keep what it learned only if it then beats the standard computer player. Nothing on the site plays this way yet: the first real training runs come next.

Saving a game no longer puts it on show

A game you save in the designer now stays a private draft, reachable only by its link. Publishing becomes its own step, with a button in the designer that opens once the site can check a score measured in your browser. Games that saving had already listed go back to drafts, their links still work, and your profile says why.

A score measured in your browser is checked by the site

When a signed-in designer measures their own saved game in the browser, the site now checks it and shows its own number, labelled as measured on your machine and not yet confirmed. This reaches the site with the next update.

The computer players think about a third faster

Games between computer players, and the measuring that rests on them, now run about 30% faster, with every move exactly as before.

You can design a hexagonal game

The designer can now turn a hex board into a hexagon, choose how many cells it has on a side, and join each pair of opposite sides so pieces cross from one to the other. A move across a joined side is offered as the short step. On a square board whose edges join, a move taught across the join is offered as the short step too. When you change a board's shape or size, walls, pieces and promotion squares that fall off it are removed, and the designer says which.

Hexagonal boards look like hexagons

A game on a hexagonal board is now drawn as one: 91 cells with no corner squares, on the play board, the replay and the designer's preview. Where a game joins two opposite sides, faded copies of the board show what lies across, and a line along the side shows who may cross it and which way.

The designer says what you changed

A game you copy and change in the designer now lists, under What you changed, each piece move and rule that differs from the game it started from, in the rules' own sentences.

The game designer explains itself better

Each starting template now arrives with its own name and a sentence about the game. A rule you pick is no longer cleared by the page redrawing a moment later, which made the first press of add it do nothing. On a laptop-width window, the board no longer slides over the form as you scroll.

Every game can be played for a rating

Until now most games in the library could only be played in the sandbox, because the site had no rated computer opponents for them. Every one of the library's 70 games now has its ladder of rated opponents, so any of them can be played in leaderboard mode.

Shogi plays by the traditional rules

A piece may now promote on a move out of the far three ranks as well as into them, as in traditional shogi. That makes the game the outside chess engine plays, so shogi can be checked against it and played against it again. The one difference left is that a perpetual check is a draw here rather than a loss for the side giving it. Shogi was measured afresh and reads 0.835.

A stronger opponent in *Intransitive*

The computer players used to count one step towards the winning corner as worth about six pieces, so they gave away material to race. They now weigh the race sensibly and also know that a piece nothing can capture is bound to win. The hardest opponent beats its old self about three games in four. Only Intransitive, three stones and the rock-paper-scissors test games play differently. Their scores moved with it, and RPS repaint now counts as a proper game. Every other game's score is unchanged.

A game's page opens faster

Opening a game's page, or starting a new game against the computer, now reads only that game's results instead of the whole library, so it comes back in about a fifth of the time. What the page shows is unchanged.

The map groups games by how alike they are

The map of games now draws a line between two games when their rules are close, thicker the closer they are, and colours the families of related games it finds. It opens with 90 lines and 13 families, each drawn as its own knot. A slider shows more or fewer lines. Hovering a game lights it and its neighbours, a close-up shows one game and the games around it, and the search box centres the game it finds. The old lines, one rule apart, are still there behind a switch. Each family of three or more games is outlined in its colour and labelled with its name, and a family can be folded down to a single dot.

Three games get their own-values opponent back

On crazyhouse, xiangqi and los alamos, the computer opponent that plays with piece values searched for that game is offered again. The values were searched afresh under the rules for counting pieces held in hand, and crazyhouse's table changed. Chess, makruk, shatranj, capablanca and shogi keep the values their rules imply, because the search found nothing better. No game's score moved.

Tunnel chess horizontal leaves the library

Its rules put pawn promotion on a row past the edge of the board, so no pawn could ever promote. It has been retired, since other wraparound versions of chess cover the same ground. Its page and past games still open. A new design that names a promotion row past its board is now refused with a sentence saying so.

A built opponent can't quietly copy another

Building an opponent that is only a scaled copy of a plan the game already offers is now refused, naming both. Before, it was saved and then played as the existing one. If an opponent built before this change clashes that way, only it is left out, and the strength panel says which one and why.

Removing a piece no longer widens a narrow blast

In the designer's one-step changes, removing the one piece a blast rule was limited to used to leave a blast that went off on every capture, turning the game into atomic chess. The rule now goes with the piece.

A design too slow to test is refused, not judged on part of its games

Before a design is accepted, a quick check plays a batch of random games on it within a time limit. If only some finished in time, the check used to judge the design on those alone, so a faster or slower computer could reach a different verdict. Now a design whose test games cannot all finish in time is refused, and the message says how many finished.

The decisions score says which piece values it judges by

The explanation beside decisions that matter now says it always judges moves by the piece values the rules imply, the same way on every game. That holds even on a game whose computer players use values fitted to that game. The number stays comparable from one game to the next, and the explanation says what that costs.

A design that was played but not scored says so

A design candidate whose games were played but that got no score used to read not measured on its card, as if nobody had played it. It now reads no score and names the run that played it. A candidate that never got as far as a game still reads not measured.

The check against the outside engine plays longer games

The command that checks which games the outside chess engine plays by the same rules now plays each test game for up to 400 moves instead of 60. Some rules only come into play late, such as promotion or a checkmating drop. The short games reached the first disagreement in only a handful of cases, and the longer ones catch nearly all of them.

Shogi no longer offers the outside engine as an opponent

The outside chess engine plays shogi by the traditional rules, which let a piece promote as it leaves the far zone and treat a checkmating pawn drop differently from this project's shogi. Games against it could stop with an error part-way through. It is no longer offered on shogi, and the game page says which two rules differ.

Every score moves: the new scoring version

The library is now scored under a new version of the score. It no longer gives a game credit for having few rules, and it judges variety by how many different positions a game's games pass through, rather than by how the rules are written. Most games rise a little; small, light games such as gardner, dobutsu and los alamos fall, and shogi climbs from the lower half into the top twenty. No game's verdict changed. On the set of known good and bad games the project checks itself against, the new version does not tell them apart any better than the old one (slightly worse, in fact): it was adopted to stop rewarding short rulebooks, not as a sharper judge. Scores from the two versions are never ranked together.

Rating the opponents says how long it takes, and takes less

The button that works out how hard each computer opponent is on a game used to promise a minute or so, and on large boards with the outside chess engine among the opponents it ran for seven minutes or more. It is now about twice as fast on those games, says honestly how long to expect (under a minute on a small board, up to ten on a large one with the outside engine), and counts its progress while it runs.

The move list says what the wolves did

In games with pieces that move by themselves after each turn, such as the wolves games, the move list now has a line under each move saying what they did, for example and the wolf on g5 takes the bishop on f4. The saved replay of a game steps through the move and the wild pieces' turn separately.

Intransitive's page states its rules

The published game intransitive used to describe itself only by pointing at its designer's video. Its description now states the rules the video gives, including that there is no draw by repetition, and says which details the video leaves open. The game itself did not change.

A one-step change that empties a rule says so

When a change in the designer's and now try panel, or in the automatic designer, leaves a rule with nothing to act on (a capture rule when nothing can be taken, castling with no rook to castle with), the change now drops that rule and says so in its sentence, instead of the result being quietly thrown away.

The stones game says why its number is not a score

The stones game is kept in the library on purpose, as an example of a game that cannot really be played. Wherever its number appears (its card, its page, a nearby game's list and the map) it now says so, so nobody takes the number for a score.

Make the game in between, from your own draft

A draft's own page now names the library game nearest to it and offers make the game in between, which opens the designer on a game halfway between the two. On the site only the draft's owner sees the button on an unlisted draft; anyone can use it on a listed one.

A reloaded game keeps how far the computer looked

On the site, the note beside each computer move saying how many moves ahead it looked now survives reloading the page. Games played before this change show no such notes.

The rules text no longer says an untouchable piece can be taken

A piece that never moves used to be described as staying until it is taken, even in games where nothing can take it, such as the stones games. It now says it stays for the rest of the game. The optional hint that checks a design's description gets the same correction, so it no longer flags those games by mistake. And four games whose rules mention a scored clock now say checkmate is looked for first.

The hand-written opponents follow each game's own rules first

The practice opponents that play by a hand-written plan now pick the plans that fit a game's own rules before the general ones: games won by capturing a particular piece get a player that goes for captures, race games a racer, drop games one that keeps pieces in hand. On 25 games the list of these opponents changes; on chess, for example, one that pushes pawns to promote replaces one that holds the centre.

A broken opponent is left out and explained, instead of failing

On crazyhouse, xiangqi and losalamos, the opponent that plays with the game's own searched piece values was built for an older version of the rules and could not play: picking it, or asking how hard each opponent is, failed with a message blaming the wrong thing. It is no longer offered, and the game's page says in one sentence why and how it gets rebuilt.

Checkmate on the last move before a draw clock now wins

A checkmate given on the very move that runs out a game's no-progress count or move limit used to be scored as the clock's result, usually a draw. It now wins, as in the official rules of chess. A stalemate on that move still ends by the clock. No game already in the library ended that way.

The computer players now value the pieces they hold in hand

On crazyhouse, shogi, dobutsu and the other games where captured pieces change sides and can be dropped back, the built-in computer players now count a captured piece in hand as fully their own. They used to count it as worth nothing until it was dropped, so they gave pieces away too easily there. Scores for those games will move when the library is next re-measured.

A one-step change no longer copies the game or swaps pieces between sides

The automatic designer now throws away a change that only re-spells the game it started from, instead of spending a tournament on it; about one change in fifty was such a copy. And add a piece, there and in the designer's and now try panel, no longer hands the second player's new pieces to the first on a game whose armies are written out side by side.

The board says how hard the computer thinks

Under each computer player the board now says how much it considers before a move, for example looks at 6,400 positions before each move, and beside each of its moves how many moves ahead it looked. On the public site, a move played before the page was reloaded shows no depth.

The library opens at once after a restart

The first visit to the library after the app starts no longer waits several seconds while the games are checked; that work now happens while the app starts up.

Every score says how many runs it rests on

Badges, the design page's measurement lines, the lines comparing two related games, and the upkeep panel now say whether a score is the mean of four runs or a single run. Where the runs behind a score can't be read, the page shows no number rather than a bare one.

A watch respects the strongest players' ration

Starting a game between two of the strongest computer players is now refused when only one of their seats is free, with a sentence saying how many are free. Before, such a game could slip one over the ration. The ration and the daily game limit also hold when two games start at the same moment. A game against the strongest player that sat idle for ten minutes, or was reopened after it ended, waits for a free place like a new game, and says so.

What the ± on a score means, now measured

The note explaining a score's ± range used to say nobody had checked it by playing more games. Someone has now: the whole library was played again from four fresh starting points, and the new average landed inside the stated range about five times in six, as it should.

The score panel counts what the score is made of

A game's page now says how many things its score measures by reading them from the scoring version the score was taken under. It used to say sixteen, a count from an older version; today's scores are made of thirteen.

Game names in one style

Every game in the library now has its name in the same lowercase style, so Cannonade, Marchfield, Reckoning and Intransitive read cannonade, marchfield, reckoning and intransitive, and chess-sweeping-bishops reads chess sweeping bishops.

The project is now called Chess variant sandbox

The site, its pages, the invitation email and the picture credits now carry the name Chess variant sandbox, where they used to say newgame. Games the computer designed are signed with the new name too. When this reaches the site everyone is signed out once, so sign in again.

A game's page says how its neighbours differ

On a game's page, games the same number of rules away are now listed most alike first, and each one says in words what kind of thing differs: for example no rules, 6 mechanisms, 1 piece between chess and berolina chess. A game nothing is close to, such as shogi, now lists the four games most like it overall (crazyhouse, courier, shatranj and makruk), and the map draws its faint line to the first of them.

Repeated failed sign-ins now have to wait

After ten failed sign-in attempts from one place within a quarter of an hour, the site asks you to wait a few minutes before trying again. This makes guessing someone's password impractical.

The explorer is now the map

The library's map is now the steerable drawing that was offered beside it as the new explorer. You can drag it, fold a family of similar games into one dot, size the dots by score or by links, tidy the layout and reset it. The old fixed map is gone, and a link kept to the explorer still opens the same view.

A new way to explore the library map

The map now has a new explorer link, a second drawing of the same seventy games you can drag, scroll and pinch, with the same lines, colours and detail panels the map already has. It now also has the map's chips, its search box, its five score filters, names on every dot, a legend and full keyboard control, plus a hide the rest switch the original map does not have. Whole families of similar games, and the nineteen games far from everything else, can now be folded into one labelled dot and opened again, and dots can be dragged and tidied. A dot's size can now be switched between how many games it links to, how it scored, what people rated it out of five, or how many games have been finished on it, and the explorer can be narrowed to unbeaten, untried or unplayed games the same way the library page can.

One-sidedness is judged more fairly, and shown even when it isn't disqualifying

A game used to be refused for favouring one side only if every single decided game went the same way. Now a game is refused only if it goes one side's way at least two times in three, which is fairer to a small sample, and weathervane half-turn is back in the rankings under the new reading. A game that leans toward one side without crossing that line now says so next to its score, instead of the lean going unmentioned.

Every library score's margin is now confirmed honest

A published score's plus-or-minus range was tested on four fresh, never-before-played game seeds rather than ones already on file, and it held: a range that claims to cover the true score about five out of six times actually did, on games nobody had looked at when the range was written down.

Play your draft without leaving the designer

The game designer's board has a fourth view, play it. A draft that passes its checks can be played right there on the large board, against the computer, by hand for both sides, or watched as the computer plays itself. Changing the draft ends the game and says so. Nothing is saved and no game played this way counts for anything. The and now try panel moved up beside the board, so on a phone it is near the top of the page. The older play it button at the foot still opens the full board page, which has the move list the inline board lacks.

And now try, inside the designer

The game designer has an and now try panel beside the verdict on your draft. It lists the changes the design loop knows how to make to the game you are editing, each in a sentence, and one press makes the change, says what it did, and leaves a game you can play. Undo takes it back. It works on a draft you have never saved, and nothing is kept until you save. On a phone the panel is at the very bottom of the page for now.

The designer speaks English, and lends you the library's pieces

In the game designer every rule card now has a title and an opening sentence in plain words, where it used to show the rule language's own keys. The add a rule menu only offers rules that can go into the game as it stands, and says why for the ones it holds back. A palette lists every distinct piece in the library, with its moves in sentences and the games that use it, and you can lift one into your draft with its moves attached. A move along a slanted line, the kind a nightrider makes, now has a sentence of its own in teach-a-move. A game with pieces held in hand shows the hand beside the board. Still rough: a piece you add yourself still has a row of seven controls for each move, and a piece lifted from the palette arrives without being placed on the board.

A game you have saved and not published is yours alone

Since the neighbours list arrived on game pages two days ago, a library game's page could name a saved, unpublished game that was within three rules of it, and say which rules differed, to anybody looking. That is closed. A saved game that is not published now appears in no other game's neighbours and nowhere on the map, for anybody but the person who made it and the person who runs the site. A game taken off the site now leaves the map as well as the library.

The designer is built around one big board

The game designer now has one large board in the middle of the page. You set the opening position up on it, picking pieces from a tray beside it. You teach a piece a move by clicking the square it should reach and choosing from plain sentences, such as one square forward-right on a hex board, where before you typed numbers. A third view shows where a piece can actually go from the opening position, with its own army in the way. It draws hex boards, boards with walls and every other board in the library. The rule cards below the board still use the rule language's own words, which is the next stage. A game with pieces held in hand does not show the hand on this board yet.

A suggestion box

The site has a suggestions link in the footer. Anybody signed in can post an idea, either for a game or a rule, or for the site itself, and sees their own ideas listed under the form. For now only the person who wrote a suggestion and the person who runs the site can read it. A post can be up to 2000 characters, and a person can post ten a day.

The designer's buttons stay in reach on a phone

On a phone the designer's verdict on your draft, and its save, play and watch buttons, now stay at the bottom of the screen. They used to sit at the end of the editor, about nine screens down. When a draft fails, the list of what is wrong scrolls inside the bar, so the buttons never move. On a computer nothing changes.

Make a new game from the map

On the library's map, clicking a game now offers and now try. It lists every change the design loop knows how to make to that game, each in a sentence, and opens the one you pick in the editor as a playable draft. Chess has 31. A dashed line between two games that differ only in their declared rules offers make the game in between, which builds the game with one rule from each side. Ten of the 55 dashed lines can do that, and the others say in a sentence why they cannot. Nothing is kept until you save, and saving still needs an account.

A page for everybody who plays

The site has a players page, linked from the footer, for anybody signed in. It opens with what nobody has claimed yet, which is the rated games nobody has played and the ones where nobody has beaten the strongest computer player. Under that it lists everybody who has finished a rated game, beside how many games they have tried, won, and beaten the strongest computer player on. Nobody appears until they have finished a game, and an empty site says so in a sentence.

The map says how to get from one game to its neighbour

Clicking a line between two games that differ by one rule now also says what a designer would do to turn one into the other, in the words of the step that does it. From chess to king of the hill it reads the game is now also won by walking the K to the centre. 23 of the 56 one-rule lines have such a step. The rest join games that differ by a rule no single design step changes.

The map shows scores, and what a rule did to them

On the library's map each game's dot is now filled by what the game scored, from the lowest score in the library to the highest, with a key beside the map. A game the checks ruled out carries a ring inside its dot, and a game with no score is hollow. Clicking a line between two games says what the differing rule did to the score, in the same words the game's own page uses, and names the three measurements that moved most. The map can also light up just the scored, unscored or out-of-date games, or the games matching a name. Games that do not match fade and stay where they are, so no line is left hanging.

This page

The site and the local app have a what's new link in the footer. It shows this changelog day by day, newest first, to everybody, signed in or not. Older entries were written for the person who runs the project, so some of them name commands and files a visitor cannot reach. Entries from here on are written for both readers.

A map of the whole library

The library has a map view. Every game is a dot, and two games that differ by one rule are joined by a line coloured by the kind of rule that differs. A dashed line marks a pair two or three rules apart with nothing between them, which is a game nobody has made yet. Arrows show which game was made from which. Chess sits in the middle of a star of 22 one-rule neighbours, and nineteen games with nothing within three rules sit in a row along the bottom. Clicking a game shows its score as its card does and lists every line touching it, nearest first, with the rule that differs in words. Clicking a line says what it claims. It works on a phone. The library's filters do not narrow the map yet, and a find box stands in for them.

The site shows the four-run scores

The site was deployed this evening with the four-run measurements copied over first, so the three entries below are live. Every score is the mean of four runs with its halved margin. Every card and game page names its run count and says how a game's runs split. Rps race and weathervane half-turn have left the rankings. For the rest of today the site is deployed after each change you would notice.

A game cannot combine en passant with a turn of several moves

A game that gave a player two moves a turn and also had en passant let that player capture their own pawn in passing, and crashed the engine outright if it had a strike rule as well. No game in the library did either, so no score was wrong. Validation now refuses the pair by name. The design loop's lengthen the turn step drops en passant from the game it makes and says so.

Every library score is the mean of four runs

All 71 games now rest on four runs where they rested on one, so the margin of error beside each score is about half what it was. A game counts as accepted only when a clear majority of its runs accept it. Under that rule 59 games are accepted and 12 refused. Rps race leaves the rankings, because three of its four runs refused it, and weathervane half-turn leaves on a two-two tie. Dull and hierarchy chess show no score where they showed a placeholder. Most scores moved by about a hundredth; three-check moved most, from 0.80 to 0.74. The site showed the one-run scores until the evening of the same day.

Every score says how many runs it rests on

The library's cards and a game's page now name the run count beside each score, so a number from one run cannot pass for an average of four. Today every game reads 1 run. When the four-run library arrives, a game's page will list its four scores and say which claim the margin of error is making. A game whose runs disagreed will say how they split, where before it would have shown one verdict as if the runs agreed. A game too few of whose runs could be read shows no score. This reached the site the same evening.

The site runs everything below

The site was deployed at the end of the day, so every entry under this date that said with the next deploy is live: the neighbours list on a game's page, carry-on games, a retired game's page and its delete button, Gardner's minichess refused, xiangqi's new score, and the wider margins of error.

A game's page lists the games a rule or two away

Every game's page now lists its nearest neighbours in the library, nearest first. Each line says what differs in words, which kind of rule it is (board, pieces, setup, captures, how the game ends), and what the change did to the score, or no clear change where the difference is inside the noise. Links are found automatically by comparing the rules, ignoring how a game happens to be written down. Chess has 22 games one rule away. A game with nothing within three rules shows its nearest four. This is the first stage of a map of the whole library; the map itself is two stages on. On the site it arrives with the next deploy.

The margin of error beside a score is wider, and says what it means

The whole library was played three more times, and a score turned out to move by about 0.025 from one run to the next, more than the margin printed beside it allowed. The margin was short by a standard small-sample correction, which is now applied, so every margin is about 15 percent wider and matches what replays show. No score changed. The library page now says that the margin describes the run it came from and is not a forecast of a replay. Fewer pairs of games count as clearly separated on the leaderboard as a result. Still open is the larger repair you chose, averaging four runs for every library game, which is being designed.

A game you walked away from can be found again

A rated game you left unfinished is offered back as a carry on entry on that game's page and on your profile, with the opponent, your seat and the moves played. Reloading a game's address, or opening it from a bookmark, draws the board where it used to drop you in the library. On the site this arrives with the next deploy.

Xiangqi was measured again, and its score rose

A fix to how the rules are compiled changed the order one xiangqi piece's moves are listed in, so xiangqi alone was played again. Its score went from about 0.73 to about 0.78, which is further than its stated margin of error allows for a change that small. The margin describes one set of games and not what a second set would give, and a task is open to measure how much a score moves between runs. Every other game's score is unchanged.

A retired game keeps its page, and can be deleted

A game that has left the library has a working page again. It shows the rules, the score and the games played on it, with a retired label where the board was. The person who made the game can delete its rules for good from a button on that page, confirmed once, and the site's keepers can too. Games played on it, ratings, votes and badges all stay and name it deleted game, so nobody's statistics change. A saved draft cannot be deleted this way yet.

A game decided by who moves first is caught more often

The check for a game that one seat wins regardless of play now reads the three strongest computer players as well as the top two. It was tried on three fresh runs of the whole library first and caught Gardner's minichess every time, which the narrower check missed. Gardner's now shows as refused and keeps its number, and nothing else in the library moved. Eleven of the 71 games are refused. The site shows this after the next deploy.

Badges are visible

Badges you have earned now appear as dated lines on your profile, with the rule under each, and a game's badges appear on its page with the figures they were earned under. A page at /badges lists every badge and what earns it, the same for everybody, so a rule is readable before it is met. No page counts badges or ranks people by them. The last earnable badge, And another thing (lost, asked for a rematch, won it), is recorded too. On main, and on the site at the next deploy.

The board says when a game counts

A rated game on the site now says so on the board, hides the take-back it would refuse, and lets you resign it. A rematch of a rated game is rated too, where it had quietly become a practice game. A watched game names who is playing, and the game page has a watch button. The replay bar no longer offers pause while a person holds a seat, and one line under the board names the marks it draws. Resigning used to leave the board playing on; it now ends the game. On main, and on the site at the next deploy.

Watching two computer players play works on the site again

The site refused a game with no person in it, which was a shortcut from the day a game became a database row rather than a decision. A visitor can again set both seats to a computer player and watch a whole game, and every board has a watch it play itself button. A watched game is nobody's game. It moves no rating, earns no badge and counts for nothing, and it is rationed like two strong games. On main, and on the site at the next deploy.

The profile shows what you have done and what is still open

A signed-in profile now lists the dated things you have done on the site, with each one's rule beneath it, and what is still open for you, grouped by kind of game. The table says how many of each game's computer players you have beaten and how far your rating is from the top. On main, and on the site at the next deploy.

Piece moves in words

A game's page now says how each piece moves in words a player would use, such as one square forward, not to take or any distance along all four diagonals, for every kind of move the rule language has, hexagonal boards and turning pieces included. The rule as written is one tap away behind the (i). On main, and on the site at the next deploy.

Cards and game pages say what a score settles

Under the score ordering, a game's card and its page now say how many measured games it clearly beats, how many clearly beat it, and how many are too close to call, instead of implying a rank the score's margin cannot support. On most games too close to call is the largest of the three. The band is absent when a score is out of date. On main, and on the site at the next deploy.

The site's own pages look like the rest of the site

The sign-in, profile, credits and privacy pages now share the app's header and stylesheet. A game named on the profile opens that game instead of the library. The profile lists what you have played first, then the rest by name. The credits read as a list of artists rather than a list of files. On main, and on the site at the next deploy.

A game's page names its firsts

A game's page now says who played it first, who the highest-rated person on it is, and everyone who has beaten its strongest computer player, in order, with the date and the side they played. Each line has an explanation behind its (i), and a line is absent when there is nothing to say. On main, and on the site at the next deploy.

Rate a game with five stars

A signed-in member can now rate a game one to five stars on its page, under a panel called What players make of it, and sees their own vote beside everybody's average with its count. A visitor who is not signed in sees the average and an invitation to sign in. The library's cards and its star-rating order use the same number. On a phone the game's name now sits above the play panel. On main, and on the site at the next deploy.

Errors appear where you are looking

An error now lands under the button you pressed, on a line of its own, or pinned to the bottom of the screen with a dismiss when no button raised it. It no longer sits at the top of a page you have scrolled past. On main, and on the site at the next deploy.

Players and designers earn badges

A game that five people have played and rated at four stars or better earns Crowd pleaser, and Proved the clanker wrong on top if its own score is low. Rating a game after finishing three games on it earns Speaks from experience, which never reads the stars you gave.

A player now earns Well read at half, three quarters and all of the rule building blocks that the rated games between them use, counted over the games they have finished.

Saving a game on the site now records the designer badges. They are for using a quarter, a half or three quarters of the rule building blocks across your listed games, for having both beaten a game's strongest computer player and designed a game that passes the check, and for the three levels of building on somebody else's game. A game built from a library game earns nothing at any level. No page draws them yet. On main, and on the site at the next deploy.

The library opens on the best games, and a game page fits a phone

The site's library now opens on the best-scoring games rather than alphabetically. A game with an out-of-date score sorts last beside the unmeasured, because the site shows no number for it. The library says Loading the library… while it warms instead of showing a blank page, every word on a card has an explanation, the order-by menu leads with the four orders a player uses, and every page change starts at the top. Tapping the (i) beside an out-of-date score now says why. On a phone a game's page opens on the play panel. On main, and on the site at the next deploy.

The site records play badges

Finishing a rated game on the site now records the badges it earned. They are for beating each named computer player on more and more games, a win over somebody rated far above you, a draw with a game's strongest computer player, a win on one game of every kind, wins by four different endings, and a game that ran to the move limit. A win by the other side leaving earns nothing, and practice games count for nothing. The privacy notice says the site keeps them. No page draws them yet. On main, and on the site at the next deploy.

A game's page shows both ratings for a computer player

Each computer player on a game's page now carries two numbers under two headings, in the tournament and on the site. The first is the fixed scale the computer players were placed on, centred on zero. The second is the scale people are rated on, and it moves as people beat the computer. The panel about beating the computer uses the same two labels, so +802 and 2302 read as one opponent on two scales. On main, and on the site at the next deploy.

The designer has no dead ends

A half-finished edit no longer takes the board away. The last valid board stays, dimmed, with the errors beside it, and it can be repaired by clicking on it. Changing a piece's letter now carries to every place that names the piece. Ctrl+Z and Ctrl+Y undo and redo, and a reload keeps the draft. A new rule card arrives filled in with pieces from your own game, so castling names your royal piece and a corner piece. When random games run out of clock, the designer says which counter ran out and what it is set to. Seventeen rule and template pairs still refuse, each for a reason about the game, such as a rule about a royal piece on a game that has none. On main, and on the site at the next deploy.

A game that leaves the library leaves the site too

When a game is taken out of the library, the site now stops listing it and starts no new games on it. Games people already played on it stay on their profiles, marked retired, and the game returns by itself if its rules come back. This also closes a hole: a retired game could still have been played by anyone who knew its address. Whether a retired game's own page should keep working is still to be decided.

"Watch it play itself" plays a real game

The designer's watch used the weakest searching computer player. On a draft where every piece can turn, that player could not see one move ahead and spent half its moves turning pieces, which looked like a broken game. The watch now uses the hard player, which costs a few hundredths of a second a move, and the board says who is playing and how many legal moves the position offers. Still open: the computer players' built-in judgement puts no value on which way a piece faces, so even strong players turn pieces more than they should. On main, and on the site at the next deploy.

The square-grid hex game is retired

The older hexagonal chess, which laid a hexagon out on a square board with walled-off corners, is out of the library. Hex glinski promoting, on a true hexagonal board, is the hexagonal game now. The library holds 71 games and all 71 scores read current. The old game's measurements are kept as history. The site still lists it until the next deploy.

The designer says what a save did

After a save, the designer now says beside the save button whether the draft was kept, how far the playability check got, and whether the game was listed and why. A refused save shows its reason in the same place. This is on main and reaches the site at the next deploy.

The site is up to date

The site was deployed this evening. It now shows a current score for all 72 games, where it had shown every score as out of date since 14 September. It also has what was waiting on main. Boards can be hexagonal. People can be invited to the site by email. A signed-in person can save a draft from the designer, and the draft is listed only if it passes the playability check. The game page and the designer no longer draw buttons the site refuses.

Two more games are refused as decided by who moves first

The replay's predictions are graded and written up. The check that refuses a game when one seat wins nearly every game between the strongest computer players now refuses three games, where it had refused one. Tunnel chess vertical and the sweeping-bishops chess are won by the first player 16 games to none. Weathervane half-turn is won by the second player 14 games to 1. A wider version of the same check would also refuse Gardner's small chess. It was seen on the same games it was first noticed on, so fresh games are played before it is adopted.

Saving a draft cannot hang the site

The check that runs when someone saves a draft now has a 15 second limit. A draft whose rules are too slow to check is refused with a sentence that says to try a smaller board or a lower move limit, and nothing half-saved is left behind. Ordinary games check in well under two seconds. That limit was the last thing the next deploy waited on.

Every game's score is current again

All 72 games in the library have a current score, taken on today's engine and rules. That includes the new hex chess example and three games that had never been scored. Run locally, the library shows them. The site still shows the old out-of-date scores until the next deploy, which waits on a time limit for the check that runs when someone saves a draft.

The designer writes sweeping pieces and hexagonal boards

The designer's move menu now offers pieces that sweep, and its board form can make the cells hexagons, so neither needs hand-written JSON. On the site, the designer no longer shows buttons the site refuses (measuring, nominating, uploading an icon, saving an opponent); a sentence says why instead. The site gets this with the next deploy.

A game's page on the site stops offering what it cannot do

On the site, a game's page no longer shows buttons that answer no such endpoint, such as work them out again or measure it again. A short sentence stands where each one was, saying the site does not run tournaments yet. The score panel now says in one plain sentence whether a score is current, and why not when it is not. The opponent menu lists you first, then the seven difficulty levels, then everything else. Run locally, the page still shows every button. This arrives with the next deploy.

Saving a draft on the site comes back

A signed-in person will be able to save a draft on the site again, check that it plays, and follow its progress. A visitor is asked to sign in. A saved draft that passes the playability check appears in the library; one that fails stays unlisted and opens only by its link. Either can be played for practice, and the site's keepers can take one down. The long measurement, nominating a game, and re-rating a game's computer players stay off on the site. This arrives with the next deploy, once the playability check has a time limit.

Hexagonal boards

A game can now say its board is hexagonal. Its rules text then calls the board hexagonal, and its boards are drawn as hexagons. The checker refuses the spellings that used to produce a plausible but wrong hex game without complaint. A promotion zone can now be any set of squares rather than whole ranks, which suits a hexagon's far edge and also a shaped zone on a square board. A new example hex chess game uses that zone; it has no score yet, and the replay gives it one. The designer's board form has no hex option yet, so a hex draft has to be written by hand.

Scores no longer look current when they are not

A stored score now reads out of date when any of the code behind it changes. Before today, changes in nine places could move a score and leave it looking current: the game loop, the tournament schedule, how played games are read back, parts of the engine the analysis reads, and the complexity count. Every score reads out of date until the replay anyway, so nothing changes on screen yet.

The library can show games you have not tried, and games nobody has played

The library page has two new filters beside unbeaten. One shows the games you have not played yet, and it needs you to be signed in. The other shows the games nobody has played at all. Each also puts a small mark on the matching cards.

You can type into a piece's fields in the designer

Clicking into a piece's letter, name, worth, icon or move settings used to redraw the whole form, so whatever you typed was lost. The click now just highlights the piece, and the fields keep what you type. Nothing on the designer page is covered by another element at a narrow window or on a phone.

A game whose goal square sits behind a wall no longer passes the rules check

A game can say that reaching a square wins, and for the second player that square is the first player's reflected. The rules check and the engine reflected it differently, so the check could pass a game whose goal for one player sat on a wall and could never be reached. The design loop was producing exactly such variants. Both now reflect the same way, the loop no longer walls off a goal, and no existing game changes.

A game the first player always wins is kept out of the rankings

A new check reads the games between the two strongest computer players in every measurement and refuses a game the first mover wins nearly every time, the way a game that never ends is refused. Tunnel chess (vertical) drops out of the rankings on it. Gardner's minichess, the other known case, is not caught from the stored games alone. Rather than pay for extra games in every measurement, the coming replay will test a cheaper reading that may catch it. The design loop also no longer tells the proposer anything about fairness from the old first-player figure, which was too noisy to grade any game.

The designer's skirmish template is a game again

The first template the designer offers, a skirmish of soldiers, could not be won by any of the computer players. Stepping into range only lost the soldier, so both sides shuffled sideways until the game was called a draw. Captures in the template are now compulsory, so the lines meet and the trades that follow decide it. Every check on a fresh draft now reads green before you change a rule. The playability check itself was not loosened.

A sweeping piece is measured on the moves it has

Two of the score's ingredients read a game's geometry straight from its rules, and until now they did not know about the new sweeping move. A game whose pieces sweep was scored as if those pieces could not move at all, which made it look like a different game. They now read sweeps like any other move. No existing game is affected, and the example game with sweeping bishops will score right when the library is next replayed.

Score ranges will be worked out by re-drawing whole pairings of players from the next scoring version, which makes them wider and more honest.

A piece can sweep along its line

A game's rules can now give a piece a sweeping move. It jumps to any square along its lines and removes every piece it passes over, its own included. A king standing on a sweeper's line is in check, just as it would be from a rook. A piece that can never be captured stops the sweep. The new example game is chess with sweeping bishops, where white has a mate in one from the start, so expect it to score poorly. Every existing game plays as before, and the whole library's scores wait on the replay.

The designer's buttons stay clickable on a long game

On a game with a long rules form, the board panel in the designer stayed in view while you scrolled, but it slid over the Which game this is panel, so its buttons could not be clicked. The whole right-hand column now stays in view instead, with its own scrollbar, and nothing hides under the board.

"Show the stuck game" shares show me's limit on the site

On the site, the designer's show the stuck game button now needs an account, like show me, and the two buttons share one limit of 50 presses an hour. On your own machine nothing changes. The message you see at the limit now names both buttons.

The site's hourly usage counts are now saved every five minutes, together with a reading of how much computer time, memory and disk the server has left, so a restart no longer loses them. As before, no count names a person.

A deploy no longer leaves the library slow for the first visitor

After a deploy that copies new results to the server, the first request for the game library used to take about 20 seconds, and the deploy's own final check gave up waiting. The deploy now opens the library once on the server before it finishes, so the check and the first visitor both find it ready. The deploy guide also gained a short list of things to check after every deploy.

Hexagonal chess is in the archive

A version of Glinski's hexagonal chess, played on a 91-cell board, is now in the archive. It needed no new rules, and it scores close to ordinary chess, so the computer players and the index handle a hex board as well as a square one. It has no promotion yet, because the rules have no way to mark a hexagon's far edge, and that is probably why strong players draw it more often than weak ones.

A low depth score is weaker evidence than a high one

The index's depth score measures how much a game rewards deeper thinking, by pitting computer players of rising strength against each other. A match one step stronger than the strongest of them, run on every committed game, shows that a high depth score mostly holds up. A low one can mean the computer players are too weak to see what the game is about. King of the hill and racing kings are the clearest cases, and intransitive is among them. Read a low depth score with that in mind.

A second match, one step lower, checked four games whose high depth scores fell away. Two of them, sardines on a torus and crazyhouse on a torus, really are deep, and the rated players simply top out. The other two are weaker than their scores say. Tunnel-vertical in particular is a forced win for whoever moves first, once a computer player looks a little way ahead, even though it scores near the top on depth. Whether the index should catch games like that is being looked into.

That look found a second one: Gardner's minichess is also won by whoever moves first once the players think hard, and both games pass every check today. It also found that the index's "first-player advantage" number is too noisy to trust for any single game, because it rests on too few games. Whether to reject, mark down or simply note games like these is still to be decided.

Games with neutral wild pieces are no longer marked down for them

A game with neutral pieces that no player controls, like the wolves games, used to lose points for "idle" piece types that no player could ever move. It no longer does. The wolves games gain a little under a tenth on that part of the score, and no other game moves. The new figures show up after the library's next replay.

A capturing piece can throw what it strikes

A game's rules can now let a capture push the struck piece onto a nearby empty square of the attacker's choosing, rather than removing it. The play page asks where to place it, and the move list names the square. The new example game is a version of the hierarchy game with this rule. Every existing game plays as before. One rare case also got stricter: in a game whose captures leave the struck piece standing, an en passant capture that promoted a piece giving check could previously be allowed when it should not have been.

A piece can merge with one of its own

A game's rules can now let a piece move onto one of its own pieces, and say what the two become. The new example game is chess where a pawn moving onto its own rook becomes a queen. Kings can never be merged away. Every existing game plays exactly as before. The new rule has no score yet, and the whole library's scores are waiting on a replay that runs after the next two rule additions, so they read as out of date until then.

The wolves game is fair to both players

The wolves game looked like it favoured the first player. Five versions with the wolves starting in different places show no first-player edge in any of them. The earlier figure came from too few games to judge.

The designer takes a draft all the way to a score

The game designer now shows each step from a draft to a measured score, with what each step costs. From a saved draft you can queue the full measurement and nominate the game for the library. The page draws the family of drafts you have saved as a tree. All of this works on your own machine. On the public site these steps stay off until the project decides which to offer.

The site counts its own use, without counting anybody

The site can now keep hourly totals of what gets used: requests per page and action, the computer time they take, and how many different signed-in people made them. Visitors without an account count only as activity. No total names a person, stores an address or sets a cookie, and the privacy page says so. The totals are held in memory for now and start being saved once the five-minute sampler lands, which should happen before more people are invited.