Rules of chess

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Main article: Chess

While the exact origins of chess are unclear, the modern rules of chess first took form in Italy during the 16^th century. The rules kept being slightly modified until the early 19^th century, when they reached their current form.

Chess is a two-player game that is played on an 8-by-8 chessboard, with thirty-two pieces (sixteen for each player) of six types; each type of piece moves in a distinct way. The goal of the game is to protect the most valuable piece, the king, and trap (checkmate) the opposing king.

Contents 1 Initial setup 2 Gameplay 2.1 Movement 2.2 Check and checkmate 2.3 Draws 2.4 Timing 3 See also 4 External links

[edit] Initial setup

Chess is played on a square board that is divided into sixty-four squares (8-by-8) of alternating color, which is very similar to that used in draughts (checkers). The chess boards used at chess tournaments have squares of approximately 50 to 65 mm (2.0 - 2.5 inches). The chess boards used at chess tournaments are usually green and buff, which is considered "easier on the eyes" than black and white, and because it is easier to distinguish occupied and empty squares when the board colors are different from the piece colors [1][2][3][4]. No matter what the true color of the board (which come in a wide variety of colors), the (thirty-two) lighter colored squares are called "white", and the (thirty-two) darker colored squares are called "black". Upon the board move sixteen "white" and sixteen "black" pieces. The chess pieces used at chess tournaments are usually "new Staunton style" shapes, and (unlike the board) often are black and white.

Sets used for play are commonly made of wood or plastic, although ornamental sets exist made of stone, glass, or metal, which are often used to decorate homes. Ivory was fairly commonly used at one time. Likewise, the chessboards themselves can be made of wood, cardboard, leather, stone, glass, or any other material that the design can be placed on. Chess tables (either of wood or stone) are sometimes made with a chess board designed into the surface. Sometimes human chess boards are drawn on the floor or ground. Many travel boards fold into a box that the pieces fit into and some of them use magnets to hold the pieces in place.

The board is placed so that a light-colored square is in the near-right corner; a dark one in the near-left. Each player controls sixteen pieces:

• 1 king
• 1 queen
• 2 rooks
• 2 bishops
• 2 knights
• 8 pawns

Note that in chess terminology, the pawn is often not called a 'piece'; with this usage, it would be said that each player has eight pieces and eight pawns. The terms 'man' or 'chessman' may be used to mean a piece or pawn.

At the beginning of the game, the pieces are arranged as shown in the diagram to the right.

• The second row from the player contains the 8 pawns
• The row nearest the player contains the remaining pieces
  • Outside corners are the rooks
  • Inside of the rooks are the knights
  • Inside of the knights are the bishops
  • Queen on her own color: white queen on the white square and black queen on the black square
  • King takes the vacant spot next to the queen.

Popular phrases used to remember the set-up, often heard in beginner's clubs, are "queen on 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.

To describe moves and locations on the board, either algebraic chess notation or the almost obsolete descriptive chess notation is used.

[edit] Gameplay

The players choose colors by mutual agreement or by random means such as coin flipping. Commonly, one player conceals a white pawn in one hand and a black pawn in the other. The other player selects a hand and plays that color.

The player controlling the white pieces moves first. While this gives white an advantage, it is not known that white can force a win if black plays perfectly. After the initial move by white, players alternate moves. Play continues until a draw is called, a player resigns or a king is trapped by means of a checkmate (see below).

[edit] Movement

Chess pieces
	King
	Queen
	Rook
	Bishop
	Knight
	Pawn

Each piece moves in a different way. Generally, a piece cannot pass through squares occupied by other pieces, but it can move to a square occupied by an opposing piece, which is then "captured" (removed from the board). Only one piece can occupy a given square.

• The rook moves orthogonally to the players (forward, backward, left or right) any number of squares.
• The bishop moves diagonally any number of squares and always stays on one of the two chequered colours.
• The queen moves orthogonally or diagonally, any number of squares.
• The king moves orthogonally or diagonally only one square at a time.
• The knight moves in an "L"-shape (two spaces in one direction and one space orthogonally to it). It is the only piece that can jump over other pieces.
• The pawn moves one space straight forward (away from the player). On its first move it can optionally move two spaces forward. If there is an enemy piece diagonally (either left or right) one space in front of the pawn, the pawn may move diagonally to capture that piece. A pawn cannot capture or jump over a piece directly in front of it.

Besides these moves, the king and either rook can do a special combination move called castling: if the king and rook have not moved yet, and all spaces between them are empty, then the king can move two squares toward the rook, and in the same turn the rook can move to the space the king has just skipped over. It is not permitted to castle when the king is threatened or would have to move through a threatened square. In serious play, care must be taken to make clear that castling is intended, e.g. by verbal announcement or by moving the king first (since the king cannot move two squares except in castling).

A pawn reaching the final rank becomes a queen in a process known as "queening" or "promotion" (or, if the player prefers, a rook, bishop or knight; this is called "underpromotion").

Unlike games such as shogi or checkers, once a chess piece is captured it is never returned to the board during the game, and individual pieces are not "promoted" to a different piece, except for pawn promotion.

If a pawn moves two squares forward on its first move, it can be captured on the square it has skipped over, as if it had moved only one square, but only during the turn immediately after its two-square move and only by an opposing pawn on its fifth rank. This is called capturing en passant.

A player may not make any move which places or leaves his king in check (see below).

In serious play, if a player having the move touches one of his pieces then he must move it if it can be legally moved. If a player touches a hostile piece then he must capture it if the piece can be captured. So long as the hand has not left the piece to be moved, the latter can be placed on any accessible square. If a player wishes to touch a piece with the sole intention of adjusting its position on a square, he must first apprise his opponent of his intention by saying J'adoube or I adjust. Only the player whose turn it is to move may adjust a piece.

A player who makes an illegal move with a piece must retract that move and make another one, if possible, with the same piece. If the mistake is only noticed later on, the game should be restarted from the position in which the error occurred. However, if blitz chess is being played (where both players have a limited time, e.g. five minutes) and the player who has made a mistake has pressed his/her clock, the other player may call the illegal move and win the game.

[edit] Check and checkmate

Main article: Checkmate

When a player makes a move that threatens the opposing king with capture, the king is said to be in check. If a player's king is in check then the player must make a move that eliminates the threat of capture, which does not necessarily mean the king must be moved. The possible moves to remove the threat of capture are:

• Move the king to a square where it is not threatened.
• Capture the threatening piece.
• Place a piece between the king and the opponent's threatening piece.

Note that the king may be in check by two pieces ("double check"). In that case, only a king move will get out of check (which could be the capture of one of the attacking pieces.) A player may never leave his king in check at the end of his move.

In informal games, it is customary to announce check when making a move that puts the opponent's king in check. However, in formal competitions this is not only unnecessary but is against the rules.

If a player's king is placed in check and there is no legal move that player can make to escape check, then the king is said to be checkmated, the game ends, and that player loses. The diagram to the right shows a typical checkmate position. The white king is threatened by the black queen; every square to which the king could move is also threatened; and he cannot capture the queen, because he would then be threatened by the rook.

Either player may resign if he feels his position is hopeless. This is common in master play.

[edit] Draws

Main article: Draw (chess)

The game ends in a draw in any of these conditions:

• The game is automatically a draw if the player to move is not in check but has no legal move. This situation is called a stalemate. An example of such a position is shown in the diagram to the right.
• There is no possibility for either player to checkmate the opponent. For example one player has a king and a knight and another only a king.
• Both players agree to a draw (Draw by agreement).

Either player may claim a draw by indicating that one of the following conditions exists:

• fifty moves have been played by each player without a piece being captured or a pawn moved.
• The same board position has been repeated three times, with the same player to move and all pieces having the same rights to move, including the right to castle or capture en passant.

At one time, if a player was able to check the opposing king continually (perpetual check) and he indicated his intention to do so, the game was drawn. This rule is no longer in effect; however, players will usually agree to a draw in such a situation, since either the threefold repetition rule or the fifty move rule will eventually go into effect.

[edit] Timing

Tournament games are played under time constraints using a Game clock. Each player must make all his moves in a specified time, or be in danger of forfeit.

• If there is a checkmate on the board, the player delivering checkmate wins, no matter what is subsequently noticed about the time.
• If player A calls attention to the fact that player B is out of time, but it is then noted that player A is also out of time, the game is drawn.
• If player A calls attention to the fact that player B is out of time, player A is not out of time, and player A has sufficient material to checkmate (either a pawn, a knight and a bishop, two bishops, a rook, or a queen), then player A wins automatically.
• If player A calls attention to the fact that player B is out of time, and player A does not have sufficient material to checkmate, the game is drawn.

Various tournament rules have been devised to prevent players from playing on with no practical chances of winning on the board, intending merely to win when their opponent runs out of time. For example, a king and rook versus a king, bishop, and pawn cannot be won by either player virtually all of the time, even though both sides theoretically have enough material to checkmate. The player with more time might play quickly in hopes of inducing a blunder or running out the opponent's clock. If a player believes his opponent is attempting to win a drawn position on time, he may appeal to a tournament official, who may impose a result or a penalty in accordance with whatever rules are in effect for that tournament.

In formal competition, each player is obliged to record each move as it is played in order to settle disputes about illegal positions and overstepping time control. Algebraic chess notation is presently used for this, though some players still use descriptive chess notation.

[edit] See also

• Chess piece
• Chessboard
• Chess terminology
• Chess strategy
• Chess tactics
• Sample chess game - a sample game, with commentary.
• Chess opening
• Middlegame
• Endgame

[edit] External links

• FIDE Laws of Chess

Chess v • d • e
Rules • Openings • Strategy • Tactics • Endgames • History • Championship