Chess
From left, a white king, black rook and queen, white pawn, black knight, and white bishop in a set of Staunton chess pieces.
Players	2
Setup time	10–60 seconds
Playing time	1 minute - 7 hours*
Rules complexity	Medium
Strategy depth	High
Random chance	None
Skills required	Tactics, Strategy
* Games by correspondence may last much longer

Chess (Sanskrit: Chaturanga) is an abstract strategy board game and mental sport for two players. The object of the game is to checkmate the opponent's king. This occurs when the king is under immediate attack (in check) and there is no way to prevent it from being captured on the next move.

Chess is one of the world's most popular board games; it is played both recreationally and competitively in clubs, tournaments, online, and by mail or e-mail (correspondence chess).

Many variants and relatives of chess are played throughout the world. The most popular, in descending order by number of players, are xiangqi in China, shogi in Japan, janggi in Korea, and makruk in Thailand. The game described in this article is sometimes known as FIDE Chess, Western Chess or International Chess to distinguish it from other variants.

Gameplay

Overview of the game

The position of the pieces at the start of a game of chess.

A typical Staunton-design chess set and clock.

Chess is played on a square board of 8 rows (called ranks) and 8 columns (called files), giving 64 squares of alternating light and dark color, which are referred to as "light squares" and "dark squares".

Each player begins the game with 16 pieces which can move in defined directions (and in some instances, limited range) and can remove other pieces from the board: each player's pieces comprise 8 pawns, 2 knights, 2 bishops, 2 rooks, 1 queen and 1 king. All pieces remove (kill) opponent's pieces by landing on the space that the opponent's piece occupies.

One player controls the white pieces and the other player controls the black pieces; the player that controls white is always the first player to move. In chess, when a king is directly threatened with capture by one or more of the opponent's pieces, the player is said to be in check. When in check, only moves that can evade check, block check, or take the offending piece are permitted. The object of the game is to checkmate the opponent; this occurs when the opponent's king is in check, and no move can be made that would prevent the king's capture. Normally a checkmate will require the cooperation of several pieces, but can also be achieved with one. A stalemate, which is a draw, occurs if a player's king is not in check and no legal moves are available; A draw can also occur if there are insufficient pieces left on the board to produce a checkmate (for example, if only the two kings remain), if a position is repeated three times in a game, or if fifty moves occur without either a check or a piece being captured.

Chess has been described not only as a game but also as an art, a science, and a sport. It is sometimes seen as an abstract war game; as a "mental martial art", and teaching chess has been advocated as a way of enhancing mental prowess.

Rules of chess

Main article: Rules of chess

Name	Letter	Picture
Pawn	P
Knight	N
Bishop	B
Rook	R
Queen	Q
King	K

When a game begins, one player controls the sixteen white pieces while the other uses the sixteen black pieces. The colors are chosen either by a friendly agreement, by a game of chance such as pick-a-hand, or by a tournament director. The first player, referred to as White, always moves first and therefore has a slight advantage over the second player, referred to as Black. The chessboard is placed so that each player has a white square in the near right hand corner, and the pieces are set out as shown in the diagram.

Each kind of chess piece moves a different way. The rook (colloquially known as a "castle") moves any number of vacant spaces vertically or horizontally, while the bishop moves any number of vacant spaces in any direction diagonally (meaning a bishop will always remain on the same color; note that each side has a bishop for each colored square, and between them they cover the whole board. Losing one bishop often creates weaknesses on the same colored square as the lost bishop). The queen is a combination of the rook and bishop (it can move any number of spaces diagonally, horizontally, or vertically). The king can move only one square horizontally, vertically, or diagonally except when a player castles. The knight can jump over occupied squares and moves two spaces horizontally and one space vertically (or vice versa), making an L shape; a knight in the middle of the board has eight squares to which it can move. Note that every time a knight moves, it changes square color.

With the exception of the knight, pieces cannot jump over each other. One's own pieces ("friendly pieces") cannot be passed if they are in the line of movement, and a friendly piece can never replace another friendly piece. Enemy pieces cannot be passed, but they can be "captured". When a piece is captured (or taken), the attacking piece replaces the enemy piece on its square (en passant being the only exception). The king cannot be captured in regular chess, only put in check. If a player is unable to get the king out of check, checkmate results, with the loss of the game.

Pawns are the only pieces which capture differently than they move. They can capture an enemy piece on either of the two spaces adjacent to the space in front of them (i.e., the two squares diagonally in front of them), but cannot move to these spaces if they are vacant. Conversely, a pawn can move forward one square, but only if that square is unoccupied; a pawn can move two squares forward but only if it has not moved yet and both squares are empty. When such an initial two square advance is made which puts that pawn horizontally adjacent to an opponent's pawn, the opponent's pawn can capture that pawn ("en passant") as if it moved forward only one square rather than two, and only on the immediately subsequent move. A pawn cannot move backward. If a pawn advances all the way to the eighth rank, it can be promoted (converted) to any other piece, except a King or another pawn — in practice, the pawn is almost always promoted to a queen.

Chess games do not have to end in checkmate — either player may resign if the situation looks hopeless. Also, games may end in a draw (tie). A draw can occur in several situations, including draw by agreement, draw by impossibility of checkmate (usually because of insufficient material to checkmate), stalemate, threefold repetition, or the fifty move rule.

Until the 1970s, at least in English-speaking countries, chess games were recorded and published using descriptive chess notation. This has been supplanted by the more compact algebraic chess notation. Several notations have emerged, based upon algebraic chess notation, for recording chess games in a format suitable for computer processing. Of these, Portable Game Notation (PGN) is the most common. Apart from recording games, there is also a notation Forsyth-Edwards Notation for recording specific positions. This is useful for adjourning a game to resume later or for conveying chess problem positions without a diagram.

Sample game

A sample chess game is made to help understand how to play chess and its rules. It explains chess through a simple demonstration, move after move. Please read this sample chess game for details.

Strategy and tactics

Main article: Chess strategy and tactics

Chess openings are a sequence of moves, often memorized, which will help a player build up their position and prepare for the middlegame. Openings are often designed to take hold of the center of the board (e4, e5, d4 and d5), develop pieces, protect the king, and create a strong pawn structure. The Classical School of chess expounds the virtues of occupying the center early using pawns and/or pieces, while Hypermodernism advocates the control of the center not by using pawns but with distant pieces. It is often important for a player to castle (a special move that moves the king from the center of the board two squares towards one of the corners) to protect the king. While studying openings can greatly improve one's results, it is important to understand the underlying reasons for each sequence of moves in an opening. This can greatly reduce the need to rely on rote memorization of the opening phase of the game. Of the utmost importance in the opening is maintaining balance, or equality.

In this position, the black knight on e6 is pinned to its king by the white bishop, and the white knight is pinned to the queen on b1. Note that the knight on b4 is still free to move, while the knight on e6 cannot move.

When taking and trading pieces, the chess piece point values becomes important. Valuations differ slightly from book to book, but generally, queens are worth 9 points, rooks are worth 5, bishops and knights are worth 3, and pawns are worth 1. Since the king's loss ends the game, it is invaluable. Although, in the endgame, when there are few pieces left on the board and there is little danger of checkmate, the fighting worth of the king is about 4. The actual value and importance of a piece will vary based upon its position and the stage of the game. If a player performs a sacrifice (e.g. exchange sacrifice), they are choosing to ignore the standard valuation of their pieces for positional or tactical gains. The beginning player should be aware that points are not an inherent part of the game; there is no scoring and chess was played long before the idea of assigning points to pieces. Instead, points are used by a player to consider whether he will come out materiall