Chess

How to play

Two players, White and Black, move one piece per turn. White moves first. The aim is to checkmate the opponent's king: attack it so that it cannot escape.

• Each side starts with a king, a queen, two rooks, two bishops, two knights and eight pawns.
• Rooks move in straight lines, bishops diagonally, queens both ways, knights in an L-shape (and may jump over pieces), kings one square in any direction.
• Pawns move forward one square (two from their starting square) and capture diagonally. A pawn that reaches the far rank is promoted, usually to a queen.
• Special moves: castling (king and rook move together), and en passant (a pawn captures a pawn that has just moved two squares past it).

You may never leave your own king in check.

Draws and the clock

A game is drawn by stalemate (no legal move but not in check), by agreement, by insufficient material, or by repetition and the fifty-move rule.

• Threefold repetition and the fifty-move rule can be claimed by the player to move: a button appears when it is available.
• Fivefold repetition and the seventy-five-move rule end the game automatically.
• If your opponent runs out of time but you could never checkmate with your remaining pieces, the game is a draw.

Clocks show the total time each player has, plus an optional bonus after every move. The first move of each side is free: if someone does not move within 30 seconds the game is aborted without changing ratings.

Chess960

The pieces on the back rank are shuffled at the start (960 possible setups, chosen at random), always with the king between the two rooks and the bishops on opposite colours. Both sides get the same arrangement.

All other rules are the same. Castling works as usual in effect: the king and the chosen rook end up on the squares they would reach in normal chess. To castle, drag your king onto your own rook.

Crazyhouse

Pieces you capture join your pocket and can be dropped back onto the board as your own, instead of making a normal move.

• A dropped piece can be placed on any empty square, except that pawns cannot be dropped on the first or last rank.
• A promoted pawn turns back into a pawn when it is captured.
• Drops may give check and checkmate.
• Because pieces keep coming back, there are no draws by insufficient material.

Three-check

Normal chess, with an extra way to win: the first player to give check three times wins immediately. The number of checks each side has given is shown next to the board.

King of the Hill

Normal chess, with an extra way to win: if your king reaches one of the four centre squares (d4, e4, d5, e5) you win at once, provided it got there legally.