The game is played on a square chequered chessboard with 64 squares arranged in an eight-by-eight square. At the start, each player (one controlling the white pieces, the other controlling the black pieces) controls sixteen pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. The object of the game is to checkmate the opponent's king, whereby the king is under immediate attack (in "check") and there is no way to remove it from attack on the next move.
The tradition of organized competitive chess started in the sixteenth century and has developed extensively. Chess today is a recognized sport of the International Olympic Committee. The first official World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; Viswanathan Anand is the current World Champion. Theoreticians have developed extensive chess strategies and tactics since the game's inception. Aspects of art are found in chess composition.
One of the goals of early computer scientists was to create a chess-playing machine, and today's chess is deeply influenced by the abilities of current chess programs and the ability to play other players online. In 1997, Deep Blue became the first computer to beat the reigning World Champion in a match when it defeated Garry Kasparov by a score of 3.5-2.5.
History
Chess originated in India,where its early form in the 6th century was chaturanga, which translates as "four divisions of the military" – infantry, cavalry, elephants, and chariots, represented respectively by pawn, knight, bishop, and rook. In Persia around 600 the name became shatranj and the rules were developed further. Shatranj was taken up by the Muslim world after the Islamic conquest of Persia, with the pieces largely retaining their Persian names. In Spanish "shatranj" was rendered as ajedrez, in Portuguese as xadrez, and in Greek as zatrikion, but in the rest of Europe it was replaced by versions of the Persian shāh ("king").
Knights Templar playing chess, Libro de los juegos, 1283.The game reached Western Europe and Russia by at least three routes, the earliest being in the 9th century. By the year 1000 it had spread throughout Europe. Introduced into the Iberian Peninsula by the Moors in the 10th century, it was described in a famous 13th century manuscript covering shatranj, backgammon, and dice named the Libro de los juegos.
Another theory, championed by David H. Li, contends that chess arose from the game xiangqi, or at least a predecessor thereof, existing in China since the 2nd century BC.
Around 1200, rules of shatranj started to be modified in southern Europe, and around 1475, several major changes rendered the game essentially as it is known today. These modern rules for the basic moves had been adopted in Italy and in Spain. Pawns gained the option of advancing two squares on their first move, while bishops and queens acquired their modern abilities. This made the queen the most powerful piece; consequently modern chess was referred to as "Queen's Chess" or "Mad Queen Chess". These new rules quickly spread throughout western Europe, with the exception of the rules about stalemate, which were finalized in the early nineteenth century.
The first modern chess tournament was held in London in 1851 and won, surprisingly, by German Adolf Anderssen, relatively unknown at the time. Anderssen was hailed as the leading chess master and his brilliant, energetic — but from today's viewpoint strategically shallow — attacking style became typical for the time. Sparkling games like Anderssen's Immortal game or Morphy's Opera game were regarded as the highest possible summit of the chess art.
Deeper insight into the nature of chess came with two younger players. American Paul Morphy, an extraordinary chess prodigy, won against all important competitors, including Anderssen, during his short chess career between 1857 and 1863. Morphy's success stemmed from a combination of brilliant attacks and sound strategy; he intuitively knew how to prepare attacks. Prague-born Wilhelm Steinitz later described how to avoid weaknesses in one's own position and how to create and exploit such weaknesses in the opponent's position. In addition to his theoretical achievements, Steinitz founded an important tradition: his triumph over the leading German master Johannes Zukertort in 1886 is regarded as the first official World Chess Championship. Steinitz lost his crown in 1894 to a much younger German mathematician Emanuel Lasker, who maintained this title for 27 years, the longest tenure of all World Champions.
The rules of chess (also known as the laws of chess) are rules governing the play of the game of chess. While the exact origins of chess are unclear, the modern rules first took form in Italy during the 16th century. The rules continued to be slightly modified until the early 19th century, when they reached essentially their current form. The rules also varied somewhat from place to place. Today FIDE (the World Chess Organization) sets the standard rules, with slight modifications by some national organizations for their own purposes. There are variations of the rules for fast chess, correspondence chess, online chess, and chess variants.
Chess is a game played by two persons on a 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 checkmate, i.e. to threaten the opponent's king with inevitable capture. Games do not necessarily end with checkmate – a player often resigns if he believes he will eventually lose. In addition, there are several ways that a game can end in a draw (a tie).
Besides the basic movement of the pieces, rules also govern the equipment used, the time control, the conduct and ethics of players, rules for handicapped players, the recording of moves using chess notation, as well as procedures for irregularities that occur during a game.
Chess is played on a chessboard, a square board that is divided into sixty-four squares (eight-by-eight) of alternating color, which is similar to that used in draughts (checkers) (FIDE 2008). No matter what the actual color 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 the near-right corner, and a black one in the near-left.
Each player has control of one of the two sets of colored pieces and are typically referred to by the nominal color of their respective pieces, i.e., White or Black. White moves first and, as in most board games, the players alternate moves. Making a move is compulsory, it is not legal to "pass", 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 lose if they exceed the time limit.
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.
Each chess piece has its own style of moving. Moves are made to vacant squares except when capturing an opponent's piece.
With the exception of the knight, pieces cannot jump over each other. When a piece is captured (or taken), the attacking piece replaces the enemy piece on its square (en passant being the only exception). The captured piece is thus removed from the game and may not be returned to play for the remainder of the game. The king cannot be captured, only put in check.
The king can move exactly one square horizontally, vertically, or diagonally. At most once in every game, each king is allowed to make a special move, known as castling.
The rook moves any number of vacant squares vertically or horizontally. It also is moved while castling.
The bishop moves any number of vacant squares in any diagonal direction.
The queen can move any number of vacant squares diagonally, horizontally, or vertically.
The knight moves to the nearest square not on the same rank, file, or diagonal. Equivalently, the knight moves two squares like the rook and then one square perpendicular to that. Its move is not blocked by other pieces, i.e. it leaps to the new square.
Pawns have the most complex rules of movement:
A pawn can move forward one square, if that square is unoccupied. If it has not yet moved, the pawn has the option of moving two squares forward provided both squares in front of the pawn are unoccupied. A pawn cannot move backward.
Pawns are the only pieces that capture differently from how 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.
The pawn is also involved in the two special moves en passant and promotion.
Castling consists of moving the king two squares towards a rook, then placing the rook on the other side of the king, adjacent to it. Castling is only permissible if all of the following conditions hold:
The king and rook involved in castling must not have previously moved;
There must be no pieces between the king and the rook;
The king may not currently be in check, nor may the king pass through or end up in a square that is under attack by an enemy piece (though the rook is permitted to be under attack and to pass over an attacked square);
The king and the rook must be on the same rank.
Pawn promotion
If a pawn advances all the way to its eighth rank, it is then promoted (converted) to a queen, rook, bishop, or knight of the same color, the choice being at the discretion of its player (usually a queen is chosen). The choice is not limited to previously captured pieces. Hence it is theoretically possible for a player to have up to nine queens or up to ten rooks, bishops, or knights if all his or her pawns are promoted. If the desired piece is not available, the player should call the arbiter to provide the piece.
End of the game
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. Unlike other pieces, the king is never actually captured or removed from the board because checkmate ends the game.
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.
Touch-move rule
In serious play, if a player having the move touches one of his pieces as if having the intention of moving it, then he must move it if it can be legally moved. So long as the hand has not left the piece on a new square, the latter can be placed on any accessible square. If a player touches one of the opponent's piece then he must capture that piece if it can be captured. If none of the touched pieces can be moved or captured there is no penalty.
When castling, the king must be the first piece touched. If the player touches his rook at the same time as touching the king, he must castle with that rook if it is legal to do so. If the player completes a two-square king move without touching a rook, he must move the correct rook accordingly if castling in that direction is legal. If a player starts to castle illegally, another legal king move must be made if possible, including castling with the other rook.
When a pawn is moved to its eighth rank, once the player takes his hand off the pawn, it can no longer be substituted for a different move of the pawn. However, the move is not complete until the promoted piece is released on that square.
If a player wishes to touch a piece with the intention of adjusting its position on a square, he must first alert his opponent of his intention by saying "J'adoube" or "I adjust". Once the game has started, only the player with the move may touch the pieces on the board.
Time control
A game played under time control will end if one player uses up all of his allotted time, see the Timing section below. There are different types of time control. Players may have a fixed amount of time for the entire game or they may have to make a certain number of moves within a specified time. Also, a small increment of time may be added for each move made.
