Chess is a game played by two people on a chessboard, with sixteen pieces (of six types) for each player. Each type of piece moves in a distinct way. The goal of the game is to checkmate, that is, to threaten the opponent’s king with inevitable capture. Games do not necessarily end with checkmate – players often resign if they believe they will lose. In addition, there are several ways that a game can end in a draw.
Besides the basic movement of the pieces, rules also govern the equipment used, the time control, the conduct and ethics of players, accommodations for physically challenged players, the recording of moves using chess notation, as well as provide procedures for resolving irregularities which can occur during a game.
Chess is played on a chessboard, a square board divided into 64 squares (eight-by-eight) of alternating color, which is similar to that used in draughts (checkers) (FIDE 2008). No matter what the actual colors of the board, the lighter-colored squares are called “light” or “white”, and the darker-colored squares are called “dark” or “black”. Sixteen “white” and sixteen “black” pieces are placed on the board at the beginning of the game. The board is placed so that a white square is in each player’s near-right corner. Horizontal rows are called ranks and vertical rows are called files.
At the beginning of the game, the pieces are arranged as shown in the diagram: for each side one king, one queen, two rooks, two bishops, two knights, and eight pawns. The pieces are placed, one on a square, as follows:
The rooks are placed on the outside corners, right and left edge.
The knights are placed immediately inside of the rooks.
The bishops are placed immediately inside of the knights.
The queen is placed on the central square of the same color of that of the player: white queen on the white square and black queen on the black square.
The king takes the vacant spot next to the queen.
The pawns are placed one square in front of all of the other pieces.
Popular mnemonics used to remember the setup are “queen on her own color” and “white on right”. The latter refers to setting up the board so that the square closest to each player’s right is white (Schiller 2003:16–17).
The player controlling the white pieces is named “White”; the player controlling the black pieces is named “Black”. White moves first, then players alternate moves. Making a move is required; it is not legal to skip a move, even when having to move is detrimental. Play continues until a king is checkmated, a player resigns, or a draw is declared, as explained below. In addition, if the game is being played under a time control players who exceed their time limit lose the game.
The official chess rules do not include a procedure for determining who plays White. Instead, this decision is left open to tournament-specific rules (e.g. a Swiss system tournament or Round-robin tournament) or, in the case of non-competitive play, mutual agreement, in which case some kind of random choice is often employed. A common method is for one player to conceal a piece (usually a pawn) of each color in either hand; the other player chooses a hand to open and reveal their color. Play then commences with white.
Each type of chess piece has its own method of movement. A piece moves to a vacant square except when capturing an opponent’s piece.
Except for any move of the knight and castling, pieces cannot jump over other pieces. A piece is captured (or taken) when an attacking enemy piece replaces it on its square (en passant is the only exception). The captured piece is thereby permanently removed from the game. The king can be put in check but cannot be captured.
- The king moves exactly one square horizontally, vertically, or diagonally. A special move with the king known as castling is allowed only once per player, per game.
- A rook moves any number of vacant squares in a horizontal or vertical direction. It also is moved when castling.
- A bishop moves any number of vacant squares in any diagonal direction.
- The queen moves any number of vacant squares in a horizontal, vertical, or diagonal direction.
- A knight moves to the nearest square not on the same rank, file, or diagonal. (This can be thought of as moving two squares horizontally then one square vertically, or moving one square horizontally then two squares vertically—i.e. in an “L” pattern.) The knight is not blocked by other pieces: it jumps to the new location.
- Pawns have the most complex rules of movement:
- A pawn moves straight forward one square, if that square is vacant. If it has not yet moved, a pawn also has the option of moving two squares straight forward, provided both squares are vacant. Pawns cannot move backwards.
- Pawns are the only pieces that capture differently from how they move. A pawn can capture an enemy piece on either of the two squares diagonally in front of the pawn (but cannot move to those squares if they are vacant).
- The pawn is also involved in the two special moves en passant and promotion.