King (chess)
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| Chess pieces | ||
|---|---|---|
| King | ||
| Queen | ||
| Rook | ||
| Bishop | ||
| Knight | ||
| Pawn | ||
- This article uses algebraic notation to describe chess moves.
In chess, the King (♔ ♚) is the most important piece. The object of the game is to capture the opponent's king. If a player's king is threatened with capture, it is said to be in check, and the player must move so as to remove the threat of capture. If it cannot escape capture on the next move, the king is said to be in checkmate, and the player which owns that king loses the game.
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In a conventional game of chess, White starts with the king in the middle-right of their first rank (between the queen and the king-side bishop). Black starts with the king directly across from the white king. In algebraic notation, the white king starts on e1 and the black king on e8.
A king can move one square in any direction (horizontally, vertically, or diagonally), that is, all moves of Chebyshev distance 1. The exceptions to this rule are that it may not move onto a square that is threatened by an enemy piece, or one that is already occupied by another piece on its own side. As a result, the opposing kings may never occupy adjacent squares, but the king can give discovered check by unmasking a bishop, rook, or queen.
As with most pieces, it captures by moving onto a square occupied by an enemy piece.
In conjunction with a rook, the king may make a special move called castling. Castling consists of moving the king two squares toward either one of the original rooks, then moving the rook onto the square over which the king crossed. Castling is allowed only when neither the king nor the castling rook has previously moved, when no squares between them are occupied, when the king is not in check, and when the king will not move across or end its movement on a square that is under enemy control.
If a player's move places the opponent's king under attack, that king is said to be in check, and the player in check is required to immediately remedy the situation. There are three possible methods to remove the king from check:
- Moving the king to an adjacent non-threatened square
- Interposing a piece between the king in check and the attacking piece in order to break the line of threat (not possible when the attacking piece is a knight, or when in double check).
- Capturing the attacking piece. (not possible in double check, unless king is capturing piece)
If none of these three options are possible, the player's king has been checkmated and the player loses the game.
- Main article: Stalemate.
A stalemate occurs when, for the player with the move:
- The player has no legal moves, and
- The player's king is not in check
If this happens, the king is said to have been stalemated and the game ends in a draw. A player who has very little or no chance of winning will often try to entice the opponent to inadvertently place the player's king in stalemate in order to avoid a loss.
In the opening and middlegame, the king will rarely play an active role in the development of an offensive or defensive position. Instead, a player will normally try to castle and seek safety on the edge of the board behind friendly pawns. In the endgame, however, the king emerges to play an active role as an offensive piece as well as assisting in the promotion of their remaining pawns.
It is not meaningful to assign a value to the king relative to the other pieces, as it cannot be captured or exchanged. In this sense, its value could be considered infinite. As an assessment of the king's capability as an offensive piece in the endgame, it is often considered to be slightly stronger than a bishop or knight — Emanuel Lasker gave it the value of a knight and a pawn (i.e. four points on the scale of chess piece point value) (Lasker 1934:73).
- Lasker, Emanuel (1934). Lasker's Chess Primer. Billings (1988 reprint). ISBN 0-7134-6241-8.
- Piececlopedia: King by Hans L. Bodlaender and Fergus Duniho.