Full legal rules — castling, en passant, promotion, check, checkmate. Take on the computer, hand the device to a friend, or send a friend a link and play them from wherever they are. Any position can be sent on as a plain link too. No account, nothing to install.
Black
Capturednothing yet
White
Capturednothing yet
Each strip lists the pieces that side has taken. Counting material: pawn 1, knight 3, bishop 3, rook 5, queen 9 — the values every beginner's book uses. The king carries no number because it is never captured. The figure beside a name, like +3, is the difference between the two totals: three points more material on the board. Promote a pawn and the new piece counts at its own value, so a queen made on the eighth rank is worth 9 like any other. This counts wood and nothing else — a rook up is no help if you are being mated next move, and a pawn down is a normal price for a safer king or a rook on an open file. Click an earlier move in the list and the strips follow the position you are reading, not the live one. The two lessons behind this row are on the front page: what the pieces are worth, the same five numbers with three playable cards on when to trade and when the count is beside the point, and three endgames for finishing a won game — king and queen, king and rook, king and pawn — because a queen up is not a result until it is mate.
White to move
Game on — good luck.
Mode — who do you want to play?
Two players means two people at this one device, taking turns on the same board. Play a friend is the online version of that: each move travels through our relay — the /relay endpoint on this same domain — and when either tab closes, or the relay restarts, the relay session ends. The relay sees which two addresses paired and when, and each player’s browser learns the other’s IP address.
Play by link — take turns whenever you like, no need to be online together. Play your move, then copy the resume link from Position & game record below and send it however you already talk.
What this way costs you — no chat, and whoever holds the link holds the game
Whoever opens it lands on this exact board, seated on the other colour, with every move so far replayed into the game record; they answer, copy the new link the board hands them, and send it back. Nothing is waiting on anybody: a reply an hour later or a week later opens the same game. What this way costs you, and both halves are real. There is no chat on this path — the chat box exists only inside a live Play a friend game, because it is a direct browser-to-browser channel and there is no second browser here to open one to. And whoever holds the link holds the game: the position, the move list and both colours all travel inside the link itself, after the #, so anyone you forward it to opens the same board and can move for either side. Nothing on this path is checked, kept or refereed by us — and no move on it goes through our relay, which is the one thing it does better than Play a friend.
Play a friend online
Read this before you press the button — exactly what leaves your device, in full
Read this before you press the button.Two players means two people at this one device, taking turns on the same board; Play a friend is the online version of that, and the one mode that leaves your device: you send someone a link, and each move goes to /relay on this domain, a small process we run that pairs the two browsers by a random game id and copies the move across. It holds no account, no game and no history; it decodes nothing and stores nothing, but it does see which two addresses paired and when. Chat is a separate path: it goes straight to the other browser, browser-to-browser and never through the relay, which means each of you learns the other’s IP address — fine for a friend you sent the link to, a bad trade with a stranger — and because nobody but the two of you can see those messages, nobody moderates them either. If either tab closes, or the relay restarts, the relay session ends where it stood and nothing re-pairs you automatically. Your own board survives that: the position stays in this tab, and the resume link on this page starts a fresh game from the same position. Two players and vs Computernever open the socket at all.
If you switch apps, lock the phone or a tab closes — what keeps the game and what ends it
Sending the link is safe to leave for. While you are still waiting for the other person, this tab may lose its connection — you switch to a chat app, your phone locks the screen — and the link keeps working: when you come back, this tab quietly takes the same game id again, so the link you already sent still opens the game you are sitting in. That holds only until they arrive. Once you are both in, the game lives in your two tabs and nowhere else: if either of you closes it, or the relay restarts, that game ends and nothing re-pairs you.
Ending a game on purpose is different: if one of you resigns, or you both agree a draw, the connection stays up and a Rematch button appears for both of you. Only a closed tab or a relay restart takes the pairing away.
Chat with your opponent
No messages yet.
Where these messages go. A message you send here goes straight to the other player’s
browser over a WebRTC data channel — it does not take the relay path your moves take.
Your moves do go through our relay, every one of them. Two honest caveats, neither of which we can
remove: setting that channel up needs one offer and one answer passed between the two tabs, and the
only thing they share at that point is the relay socket, so the relay still sees which two
addresses paired and when — never a word of what you type. And a direct connection means
each player’s browser learns the other’s IP address; that is how peer-to-peer
works everywhere, it is why there is no public matchmaking here, and it is a fair trade with someone
you already sent a link to. There is no TURN server, so no third party carries your messages; one
outside machine is involved, the public STUN server stun.l.google.com:19302, and its
whole job is to tell your browser what its own address looks like from the internet. Nothing is
kept: no transcript, no history, nothing written to this device, and closing either tab ends it.
Play as
Computer strength
What Easy, Normal and Hard change.
Each setting looks a different number of half-moves ahead — Easy
1, its own move and nothing after it; Normal
2, its move and your best reply; Hard
3, its move, your reply and its own follow-up
— and all three then keep following captures a few moves further before
scoring what is left. The bigger difference is the variety pool: each level
picks at random among the moves it scored within a fixed margin of its best,
250 hundredths of a pawn on Easy (two and a
half pawns of slack),
90 on Normal and
0 on Hard, so Easy and Normal often answer the
same position with a different move next game while Hard, given no margin at
all, repeats its top-scoring move every time. Easy is the one to learn on
— a pool narrower than a knight can leave a pawn hanging but will not
hand you a piece — Normal is a real game, Hard is the same search with
the randomness taken away, and if the board reports a backup opponent,
that simpler engine caps its search at
2 half-moves, so Hard is a shallower
Hard there while the three pools stay the same.
Position & game record
Copy link to this position (under the board) puts the position — and the moves that led to it, if they fit — after the # in the URL. Browsers never send that part of a URL, so it travels inside the link itself and is not in anyone's request log. Whoever opens it sees exactly this board.
This tab already keeps the game you are playing: reload it, or come back after your phone locks the screen, and the board is exactly where you left it. That copy lives in this tab’s own history entry — not in site storage, and it does not reach a second tab, another browser or another device. The resume link does: unlike the share link above it also carries who plays which colour, so whoever opens it is seated on the side the link names, on the position the link names. It is a fresh board for two people, not a reconnection: the relay session behind a friend game is gone the moment either tab closes, and nothing re-pairs you automatically, so opening this link is you two starting a new game on the position the old one stopped at — the relay had kept nothing to give back.
Moves
No moves yet — White starts.
Click a piece to see its legal moves, then click a square — or just drag it. Click any move above — or tab into the list and use ← → — to see that position again; nothing is taken back and the game plays on.