Rules of chess


The rules of chess are rules governing the play of the game of chess. While the exact origins of chess are unclear, modern rules first took form during the Middle Ages. 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, the standard rules are set by FIDE, the international governing body for chess. Slight modifications are made by some national organizations for their own purposes. There are variations of the rules for fast chess, correspondence chess, online chess, and Chess960.
Chess is a two-player board game using a chessboard and sixteen pieces of six types for each player. Each type of piece moves in a distinct way. The object of the game is to checkmate the opponent's king. Games do not necessarily end in checkmate; players often [|resign] if they believe they will lose. A game can also end in a draw in several ways.
Besides the basic moves of the pieces, rules also govern the equipment used, time control, conduct and ethics of players, accommodations for physically challenged players, and recording of moves using chess notation. Procedures for resolving irregularities that can occur during a game are provided as well.

Initial setup

Chess is played on a chessboard, a square board divided into 64 squares of alternating color, which is similar to that used in draughts . 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 ' and vertical rows are called '.
Each player controls sixteen pieces:
PieceKingQueenRookBishopKnightPawn
Number112228
Symbols






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:
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.

Gameplay

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 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 of each color in either hand; the other player chooses a hand to open, and receives the color of the piece that is revealed.

Movement

Basic moves

Each type of chess piece has its own method of movement. A piece moves to a vacant square except when an opponent's piece.
Except for any move of the knight and [|castling], pieces cannot jump over other pieces. A piece is captured when an attacking enemy piece replaces it on its square. The captured piece is thereby permanently removed from the game. The king can be put in check but cannot be captured.
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. It is not allowed to move both king and rook in the same time, because "Each move must be played with one hand only.". Castling is only permissible if all of the following conditions hold:
When a pawn advances two squares from its original square and ends the turn adjacent to a pawn of the opponent's on the same, it may be captured by that pawn of the opponent's, as if it had moved only one square forward. This capture is only legal on the opponent's next move immediately following the first pawn's advance. The diagrams on the right demonstrate an instance of this: if the white pawn moves from a2 to a4, the black pawn on b4 can capture it en passant, moving from b4 to a3 while the white pawn on a4 is removed from the board.

Pawn promotion

If a player advances a pawn to its eighth rank, the pawn is then promoted to a queen, rook, bishop, or knight of the same color at the choice of the player. The choice is not limited to previously 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 of their pawns are promoted. If the desired piece is not available, the player must call the to provide the piece.

Check

A king is in check when it is under attack by at least one enemy piece. A piece unable to move because it would place its own king in check may still deliver check to the opposing player.
It is illegal to make a move that places or leaves one's king in check. The possible ways to get out of check are:
If it is not possible to get out of check, the king is checkmated and the game is over.
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 check is rarely announced.

End of the game

Checkmate

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, capturing the opponent's king is not allowed.
The diagram shows an example checkmate position. The white king is threatened by the black queen; the square to which the king could move is also threatened; it cannot capture the queen, because it would then be in check by the rook.

Resigning

Either player may resign at any time and their opponent wins the game. Players typically resign when they believe they are very likely to lose the game. A player may resign by saying it verbally or by indicating it on their in any of three ways: by writing "resigns", by circling the result of the game, or by writing "1–0" if Black resigns or "0–1" if White resigns. Tipping over the king also indicates resignation, but it is not frequently used. Stopping both clocks is not an indication of resigning, since clocks can be stopped to call the arbiter. An offer of a handshake is not necessarily a resignation either, since one player could think they are agreeing to a draw.

Dead position

The rules speak of a when neither player can theoretically win the game.
The game ends in a draw if any of these conditions occur:
At one time, if a player was able to check the opposing king continually and the player indicated their 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 rule on threefold repetition or the fifty-move rule will eventually be applicable,.

Flag-fall

A game played under time control will end as a loss for a player who uses up all of their allotted time, which is called, unless the opponent cannot possibly checkmate him. 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.

Competition rules

The following rules are the rules used for "" games. They are defined by the FIDE Laws of Chess.. The FIDE Laws of Chess define the rules for Standard chess, Rapid chess, Blitz chess and guidelines for Chess960. Some rules are specifically adapted for disabled players. As the rules cover OTB play, they cannot be directly applied to computer chess or online chess, played on a computer device. The rules for correspondence chess are defined by the ICCF.

Moving the pieces

The movement of pieces is to be done with one hand. Once the hand is taken off a piece after moving it, the move cannot be retracted unless the. When castling, the player should first move the king with one hand and then move the rook with the same hand.
In the case of a pawn promotion, if the player releases the pawn on the eighth rank, the player must promote the pawn. After the pawn has moved, the player may touch any piece not on the board and the promotion is not finalized until the new piece is released on the promotion square.

Touch-move rule

In serious play, if a player having the move touches a piece as if having the intention of moving it, then the player must move it if it can be legally moved. So long as the hand has not left the piece on a new square, any legal move can be made with the piece. If a player touches one of the opponent's pieces then that piece must be if there is a legal move that does so. 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 the king and a rook, the player 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, the player 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.
If a player moves a pawn to its eighth rank, it cannot be substituted for a different move of the pawn when the player has stopped touching it. 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, the player must first alert the opponent of this 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.

Timing

Tournament games are played under time constraints, called time controls, using a chess clock. Players must make their moves within the time control or forfeit the game. There are different types of time controls applied. For standard chess, different periods can be defined with different fixed times. For rapid and blitz chess, only one period can be defined where all moves must be performed. Additionally, an increment or delay per move may be defined.
The United States Chess Federation rule is different. USCF Rule 14E defines "insufficient material to win on time", that is lone king, king plus knight, king plus bishop, and king plus two knights opposed by no pawns, and there is no forced win in the final position. Hence to win on time with this material, the USCF rule requires that a win can be forced from that position, while the FIDE rule merely requires a win to be possible.
In the last period of a standard chess game or rapid games, if played without increment, a special set of rules applies regarding the clock, referenced as "Quickplay Finishes". These rules allow a player with under two minutes time to request an increment introduced, or request a draw based on claiming no progress or no effort, to be ruled by the arbiter. These rules have been relevant when playing with mechanical clocks, which do not allow setting an increment and are today with digital clocks of second importance only, as playing with increment is recommended.

Recording moves

Each square of the chessboard is identified with a unique pair of a letter and a number. The vertical are labeled a through h, from White's left to White's right. Similarly, the horizontal are numbered from 1 to 8, starting from the one nearest White's side of the board. Each square of the board, then, is uniquely identified by its file letter and rank number. The white king, for example, starts the game on square e1. The black knight on b8 can move to a6 or c6.
In formal competition, each player is obliged to record each move as it is played in a chess notation in order to settle disputes about illegal positions, overstepping time control, and making claims of draws by the fifty-move rule or repetition of position. Algebraic chess notation is the accepted standard for recording games today. There are other systems such as ICCF numeric notation for international correspondence chess and the obsolete descriptive chess notation. The current rule is that a move must be made on the board before it is written on paper or recorded with an electronic device.
Both players should indicate offers of a draw by writing "=" at that move on their score sheet. Notations about the time on the clocks can be made. If a player has less than five minutes left to complete all of their moves, they are not required to record the moves. The score sheet must be made available to the at all times. A player may respond to an opponent's move before writing it down.

Adjournment

Irregularities

Illegal move

A player who makes an must retract that move and make a legal move. That move must be made with the same piece if possible, because the touch-move rule applies. If the illegal move was an attempt to castle, the touch-move rule applies to the king but not to the rook. The arbiter should adjust the time on the clock according to the best evidence. If the mistake is only noticed later on, the game should be restarted from the position in which the error occurred. Some regional organizations have different rules.
A player may correct an illegal move if the player has not pressed their clock. If a player has pressed their clock, the illegal move may be stated by the arbiter intervening or by the opponent claiming the illegal move. If the arbiter does not intervenes and the opponent moves, the illegal move is accepted and without penalty.
According to the FIDE Laws of Chess, the first stated completed illegal move results in a time penalty. The time penalty consists of giving the opponent two minutes extra time in standard and rapid chess, one minute extra time in Blitz. The second stated completed illegal move by the same player results in the loss of the game, unless the position is such that it is impossible for the opponent to win by any series of legal moves in which case the game is drawn. A move is completed when it has been made and the player has pressed the clock.

Illegal position

If it is discovered during the game that the starting position was incorrect, the game is restarted. If it is discovered during the game that the board is oriented incorrectly, the game is continued with the pieces transferred to a correctly oriented board. If the game starts with colours reversed, the game is restarted if less than 10 moves have been made by both players, otherwise the game is continued. Some regional organizations have different rules.
If a player knocks over pieces, it is their responsibility to restore them to their correct position on their time. If it is discovered that an illegal move has been made, or that pieces have been displaced, the game is restored to the position before the irregularity. If that position cannot be determined, the game is restored to the last known correct position.

Conduct

Players may not use any notes, outside sources of information, or advice from other people. Analysis on another board is not permitted. Scoresheets are to record objective facts about the game only, such as time on the clock or draw offers. Players may not leave the competition area without permission of the arbiter.
High standards of etiquette and ethics are expected. Players should shake hands before and after the game. Generally a player should not speak during the game, except to offer a draw, resign, or to call attention to an irregularity. An announcement of "check" is commonly made in informal games but is not recommended in officially sanctioned games. A player may not distract or annoy another player by any means, including repeatedly offering a draw.
Due to increasing concerns about the use of chess engines and outside communication, mobile phone usage is banned. The first forfeit by a high-profile player, for their phone ringing during play, occurred in 2003. In 2014 FIDE extended this to ban all mobile phones from the playing area during chess competitions, under penalty of forfeiture of the game or even expulsion from the tournament. However, the rules also allow for less rigid enforcement in amateur events.

Equipment

The size of the squares of the chessboard should be approximately 1.25 to 1.3 times the diameter of the base of the king, or 50 to 65 mm. Squares of approximately 57 mm normally are well-suited for pieces with the kings in the preferred size range. The darker squares are usually brown or green and the lighter squares are off-white or buff.
Pieces of the Staunton chess set design are the standard and are usually made of wood or plastic. They are often black and white; other colors may be used but they would still be called the "white" and "black" pieces. The height of the king should be 85 to 105 millimetres. A height of approximately 95 to 102 mm is preferred by most players. The diameter of the king should be 40 to 50% of its height. The size of the other pieces should be in proportion to the king. The pieces should be well balanced.
In games subject to time control, a chess clock is used, consisting of two adjacent clocks and buttons to stop one clock while starting the other, such that the two component clocks never run simultaneously. The clock can be analog or digital though a digital clock is highly preferred under both USCF and FIDE rulesets. This is since most tournaments now include either an increment or delay to their time controls. Before the start of the game, either the arbiter decides, or whoever is playing Black, where the chess clock is placed.

History

The rules of chess have evolved much over the centuries from the early chess-like games played in India in the 6th century. For much of that time the rules have varied from area to area. The modern rules first took form in Italy during the 13th century, giving more mobility to pieces that previously had more restricted movement. Such modified rules entered into an accepted form during the late 15th century or early 16th century. The basic moves of the king, rook, and knight are unchanged. Pawns originally did not have the option of moving two squares on their first move and promoted only to a queen if they reached the eighth rank. The queen was originally the fers or farzin, which could move one square diagonally in any direction. In European chess it became able to leap two squares diagonally, forwards, backwards, or to left or right on its first move; some areas also gave this right to a newly promoted pawn. In the Persian and Arabic game the bishop was a pīl or fīl which moved two squares diagonally with jump. In the Middle Ages the pawn could only be promoted to the equivalent of a queen if it reached its eighth rank. During the 12th century the squares on the board sometimes alternated colors, and this became the standard in the 13th century ; whence the word "chequered"/"checkered".
Between 1200 and 1600 several laws emerged that drastically altered the game. Checkmate became a requirement to win; a player could not win by capturing all of the opponent's pieces. Stalemate was added, although the outcome has changed several times. Pawns gained the option of moving two squares on their first move, and the en passant rule was a natural consequence of that new option. The king and rook acquired the right to castle.
Between 1475 and 1500 the queen and the bishop also acquired their current moves, which made them much stronger pieces. When all of these changes were accepted the game was in essentially its modern form.
The rules for pawn promotion have changed several times. As stated above, originally the pawn could only be promoted to the queen, which at that time was a weak piece. When the queen acquired its current move and became the most powerful piece, the pawn could then be promoted to a queen or a rook, bishop, or knight. In the 18th century rules allowed only the promotion to a piece already captured, e.g. the rules published in 1749 by François-André Danican Philidor. In the 19th century this restriction was lifted, which allowed for a player to have more than one queen, e.g. the 1828 rules by Jacob Sarratt.
Two new rules concerning draws were introduced, each of which have changed through the years:
Another group of new laws included the touch-move rule and the accompanying "j'adoube/adjust" rule; that White moves first ; the orientation of the board; the procedure if an illegal move was made; the procedure if the king had been left in check for some moves; and issues regarding the behavior of players and spectators. The Staunton chess set was introduced in 1849 and it became the standard style of pieces. The size of pieces and squares of the board was standardized.
Until the middle of the 19th century, chess games were played without any time limit. In an 1834 match between Alexander McDonnell and Louis-Charles Mahé de La Bourdonnais, McDonnell took an inordinate amount of time to move, sometimes up to 1½ hours. In 1836 Pierre Charles Fournier de Saint-Amant suggested a time limit, but no action was taken. At the 1851 London tournament, Staunton blamed his loss in his match against Elijah Williams on Williams' slow play; one game was adjourned for the day after only 29 moves. The next year a match between Daniel Harrwitz and Johann Löwenthal used a limit of 20 minutes per move. The first use of a modern-style time limit was in an 1861 match between Adolph Anderssen and Ignác Kolisch.

Codification

The first known publication of chess rules was in a book by Luis Ramírez de Lucena about 1497, shortly after the movement of the queen, bishop, and pawn were changed to their modern form. Ruy López de Segura gave rules of chess in his 1561 book Libro de la invencion liberal y arte del juego del axedrez. In the 16th and 17th centuries, there were local differences concerning rules such as castling, pawn promotion, stalemate, and en passant. Some of these differences persisted until the 19th century ; for example differences in castling rules persisted in Italy until the late 19th century.
As chess clubs arose and tournaments became common, there was a need to formalize the rules. In 1749 Philidor wrote a set of rules that were widely used, as well as rules by later writers such as the 1828 rules by Jacob Sarratt and rules by George Walker. In the 19th century, many major clubs published their own rules, including The Hague in 1803, London in 1807, Paris in 1836, and St. Petersburg in 1854. In 1851 Howard Staunton called for a "Constituent Assembly for Remodeling the Laws of Chess" and proposals by Tassilo von Heydebrand und der Lasa were published in 1854. Staunton had published rules in Chess Player's Handbook in 1847, and his new proposals were published in 1860 in Chess Praxis; they were generally accepted in English-speaking countries. German-speaking countries usually used the writings of chess authority Johann Berger or Handbuch des Schachspiels by Paul Rudolf von Bilguer, first published in 1843.
In 1924, Fédération Internationale des Échecs was formed and in 1929 it took up the task of standardizing the rules. At first FIDE tried to establish a universal set of rules, but translations to various languages differed slightly. Although FIDE rules were used for international competition under their control, some countries continued to use their own rules internally. In 1952 FIDE created the Permanent Commission for the Rules of Chess and published a new edition of the rules. The third official edition of the laws was published in 1966. The first three editions of the rules were published in French, with that as the official version. In 1974 FIDE published the English version of the rules. With that edition, English became the official language of the rules. Another edition was published in 1979. Throughout this time, ambiguities in the laws were handled by frequent interpretations that the Rules Commission published as supplements and amendments. In 1982 the Rules Commission rewrote the laws to incorporate the interpretations and amendments. In 1984 FIDE abandoned the idea of a universal set of laws, although FIDE rules are the standard for high-level play. With the 1984 edition, FIDE implemented a four-year moratorium between changes to the rules. Other editions were issued in 1988 and 1992,.
The rules of national FIDE affiliates are based on the FIDE rules, with slight variations. Kenneth Harkness published popular rulebooks in the United States starting in 1956, and the USCF continues to publish rulebooks for use in tournaments it sanctions.
In 2008, FIDE added the variant Chess960 to the appendix of the "Laws of Chess". Chess960 uses a random initial set-up of main pieces, with the conditions that the king is placed somewhere between the two rooks, and bishops on opposite-color squares. The castling rules are extended to cover all these positions.
In the 21st century, rules about such things as mobile phones and unauthorised use of chess engines were introduced.

Variations

From time to time, rules have been introduced at certain tournaments to discourage players from agreeing to short draws. One such case was the "no drawing or resigning during the first 30 moves" rule used at the.