Chess rules — how to play chess

Two armies of sixteen pieces, sixty-four squares, and one aim: trap the enemy king so that it has no way out. Nothing is hidden and nothing is left to chance.

This page covers every rule, including the three unusual moves — castling, en passant and promotion — that catch out people who learned from a friend.

The board and the starting position

The board is eight squares by eight, set so that each player has a light square in the corner on their right. The columns are files, lettered a to h from white's left; the rows are ranks, numbered 1 to 8 from white's side. So every square has a name, from a1 in white's left-hand corner to h8.

Each side has sixteen pieces:

• eight pawns across the second rank (the seventh for black);
• behind them, from each corner inwards, a rook, a knight and a bishop;
• the queen on the middle square of her own colour — white's on the light square d1, black's on the dark square d8. "Queen on her own colour" is the rule to remember;
• the king beside her, on the e-file.

White moves first, and then the players take turns. You choose your colour before the game — white, black, or a coin toss — both against the computer and when you open a table for a friend. At a friend's table the colours swap on every rematch.

How the pieces move

Every piece except the knight moves in straight lines and cannot jump over anything in its way. A piece captures by moving onto a square held by an enemy piece, which comes off the board.

• The king moves one square in any direction, but never onto a square an enemy piece attacks.
• The bishop moves diagonally, so it spends the whole game on squares of one colour.
• The knight moves in an L-shape: two squares one way, then one to the side. It is the only piece that jumps over others.
• The pawn moves one square straight forward, or two from its starting square if both are empty. It is the only piece that captures differently from how it moves: one square diagonally forward. It never moves backwards.

The values are a guide to whether a trade is good, not a rule. The king has none, because losing it loses the game.

Check and checkmate

A king that is attacked is in check, and must be got out of it on the very next move: by moving the king to a safe square, by capturing the piece giving check, or by putting a piece in the way. (Blocking does not work against a knight, or against a piece right next to the king.)

You may never make a move that leaves your own king in check. The table will not accept one.

When a king is in check and there is no way out, that is checkmate, and the side that gave it wins. The king is never actually captured.

Castling

Once per game, each side may move the king and a rook together. The king moves two squares towards a rook, and the rook jumps over it to the square right beside it.

• Short castling: the king goes from e1 to g1 and the rook from h1 to f1 (for black, e8 to g8 and h8 to f8).
• Long castling: the king goes from e1 to c1 and the rook from a1 to d1 (for black, e8 to c8 and a8 to d8).

You may castle only when:

• neither the king nor that rook has moved yet;
• every square between them is empty;
• the king is not in check;
• the king does not pass through or land on an attacked square.

Only the king's path matters. In long castling the rook crosses b1 (or b8), which may be attacked as long as it is empty.

En passant

A pawn that moves two squares from its start can slip past an enemy pawn that would have captured it had it moved one. So the enemy pawn gets one chance to capture it en passant ("in passing"): it moves diagonally onto the square that was skipped, and the pawn that moved is removed.

For example, a white pawn stands on e5 and black plays d7–d5. White may capture on d6, and the black pawn on d5 comes off. The capture must be made on the very next move, or the chance is gone for good.

Promotion

A pawn that reaches the far rank is promoted on the same move, into a queen, rook, bishop or knight of its own colour — the player picks. The queen is offered first because she is almost always right, but now and then a knight gives a winning check, or a queen would leave the opponent stalemated. You can have two or three queens at once.

How the game ends

You win by checkmate, when your opponent resigns, or when their time bank runs out. Either player may resign at any time; it takes two presses, so a stray click doesn't end a game.

The game is a draw in four cases:

• Stalemate: the player to move is not in check but has no legal move. However far ahead the other side is, it is a draw.
• Threefold repetition: the same position appears for the third time — same pieces on the same squares, same player to move, same castling and en passant rights. The three need not come in a row.
• The fifty-move rule: fifty moves by each side with no capture and no pawn move.
• Insufficient material: king against king, king and a single bishop or knight against king, or only bishops left, all on squares of one colour. Nobody can give checkmate.

Draws are declared automatically by the table the moment they happen. Nobody has to claim them.

At a table with a friend there is one more: a draw by agreement. Either player may offer one, and the other accepts or declines it — playing a move instead of answering declines it too. You can offer once per move.

Time control

Every game here is played with a clock, and each player has two kinds of time: a time bank for the whole game, and a per-move timer that starts afresh on every move.

On your turn the per-move timer runs first, and while it runs your bank is untouched. When it runs out, time starts coming out of the bank. Unused per-move time is not saved up: move in two seconds with ten on the timer, and your next move still gets exactly ten.

If your bank reaches zero, you lose on time — unless your opponent has only their king left. Then it is a draw, because a lone king can never checkmate.

There are four presets, written as bank + per-move:

You choose before the game, in the panel beside the board: against the computer before your first move, and at a friend's table while you wait for them — right up to the start. Play again keeps the clock and the score; after a game, whoever opened the table can press Change settings to change the clock or their colour first, and the score is kept then too.

Against the computer, your clock stops if you switch to another tab and restarts when you come back. At a friend's table, your friend presses Ready when they are set, and whoever opened the table presses Start; the clocks start then, and keep running even if a connection drops. If your opponent stays away for more than a minute, you can claim the win.

Reading chess notation

The move list beside the board records the game in algebraic notation, the standard way chess is written down.

• A move names the piece and the square it went to. K is the king, Q the queen, R a rook, B a bishop and N a knight. Pawns get no letter: e4 is a pawn moving to e4, Nf3 a knight moving to f3.
• x marks a capture: Bxc6. A pawn capture names the pawn's file: exd5.
• + is check and # is checkmate: Qh5+, Qxf7#.
• O-O is short castling, O-O-O long castling.
• e8=Q is a pawn promoting to a queen on e8.
• If two identical pieces could reach the same square, the one that moved is named by its file or rank: Nbd2, R1e2.

Ready? Play chess against the computer, or read how to win at chess first.