Editing Chess (section)

==Rules==
{{Main|Rules of chess}}
The rules of chess are published by [[FIDE]] (Fédération Internationale des Échecs; "International Chess Federation"), chess's world governing body, in its ''Handbook''.<ref name="FideLawsOfChess">{{cite web |url=https://handbook.fide.com/chapter/E012023 |title=Fide Laws of Chess taking effect from 1 January 2023 |access-date=1 January 2023 |publisher=FIDE |df=dmy-all |archive-date=1 January 2023 |archive-url=https://web.archive.org/web/20230101083033/https://handbook.fide.com/chapter/E012023 |url-status=live }}</ref> Rules published by [[List of chess federations|national governing bodies]], or by unaffiliated chess organizations, commercial publishers, etc., may differ in some details. FIDE's rules were most recently revised in 2023.

===Setup===
[[File:ChessStartingPosition.jpg|thumb|left|upright=1.0|Setup at the start of a chess game]]
[[Chess set]]s come in a wide variety of styles. The [[Staunton chess set|Staunton pattern]] is the most common, and is usually required for competition.<ref name=fideequip>{{Cite web |title=C. General Rules and Technical Recommendations for Tournaments / 02. Chess Equipment / 01. Standards of Chess Equipment / FIDE Handbook |url=https://handbook.fide.com/chapter/StandardsOfChessEquipment2022 |access-date=2025-01-19 |website=International Chess Federation (FIDE) |language=en}}</ref> Chess sets come with [[chess piece|pieces]] in two colors, referred to as [[White and Black in chess|''white'' and ''black'']], regardless of their actual color; the players controlling the color sets are referred to as ''White'' and ''Black'', respectively. Each set comes with at least the following 16 pieces in both colors: one [[King (chess)|king]], one [[Queen (chess)|queen]], two [[Rook (chess)|rooks]], two [[Bishop (chess)|bishops]], two [[Knight (chess)|knights]], and eight [[Pawn (chess)|pawns]].<ref name=FideLawsOfChess/>

The game is played on a square [[Chessboard|board]] of eight rows (called ''{{chessgloss|ranks}}'') and eight columns (called ''{{chessgloss|files}}''). Although it does not affect gameplay, by convention the 64 squares alternate in color and are referred to as {{em|light}} and {{em|dark}} squares.<ref name="FideLawsOfChess"/><!--FIDE uses "white and black squares" in the citation; new citation needed--->
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{{Chess diagram   
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|rd|nd|bd|qd|kd|bd|nd|rd
|pd|pd|pd|pd|pd|pd|pd|pd
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|pl|pl|pl|pl|pl|pl|pl|pl
|rl|nl|bl|ql|kl|bl|nl|rl
| Initial position: {{em|first row:}} rook, knight, bishop, queen, king, bishop, knight, rook; {{em|second row:}} pawns
}}
To start the game, White's pieces are placed on the first rank in the following order, from left to right: rook, knight, bishop, queen, king, bishop, knight, rook. Pawns are placed on each square of the second rank. Black's position mirrors White's, with equivalent pieces on every file.<ref name="FideLawsOfChess"/> The board is oriented so that the right-hand corner nearest each player is a light square; as a result the white queen always starts on a light square, while the black queen starts on a dark square. This may be remembered by the phrases "white on the right" and "queen on her color".<ref>{{harvp|Hooper|Whyld|1992|p=47}}</ref>

In competition, the piece colors are allocated to players by the organizers. In informal games, colors may be decided either by mutual agreement, or randomly, for example by a coin toss, or by one player concealing a white pawn in one hand and a black pawn in the other and having the opponent choose.{{citation needed|date=January 2025}}

===Movement===
White moves first, after which players alternate turns. One piece is moved per turn (except when [[castling]], during which two pieces are moved). In the diagrams, dots mark the squares to which each type of piece can move if unoccupied by friendly pieces and there are no intervening piece(s) of either color (except the knight, which leaps over any intervening pieces). With the sole exception of ''[[en passant]]'', a piece captures an enemy piece by moving to the square it occupies, removing it from play and taking its place. The pawn is the only piece that does not capture the way it moves, and it is the only piece that moves and captures in only one direction (forwards from the player's perspective). A piece is said to ''control'' empty squares on which it could capture, ''attack'' squares with enemy pieces it could capture, and ''defend'' squares with pieces of the same color on which it could recapture. Moving is compulsory; a player may not skip a turn, even when [[zugzwang|having to move is detrimental]].

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{{Chess diagram  
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|Moves of the king
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|Moves of a rook
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|oo|oo|oo|rl|oo|oo|oo|oo
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}}
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{{Chess diagram  
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|Moves of a bishop
|  |  |  |  |  |  |  |oo
|oo|  |  |  |  |  |oo|
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|  |  |oo|  |oo|  |  |
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|oo|  |  |  |  |  |oo|
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{{Chess diagram  
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|Moves of a queen
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|oo|oo|oo|ql|oo|oo|oo|oo
|  |  |oo|oo|oo|  |  | 
|  |oo|  |oo|  |oo|  | 
|oo|  |  |oo|  |  |oo| 
}}
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{{Chess diagram 
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|Moves of a knight
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{{Chess diagram  
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|Moves of a pawn
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|  |ox|oo|ox|  |  |pd|
|  |  |pl|  |  |xx|xo|xx
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|ox|oo|ox|  |  |pd|  |
|  |pl|  |  |xx|xo|xx|
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* The [[king (chess)|king]] moves one square in any direction. There is also a special move called ''[[#Castling|castling]]'' which moves the king and a rook. The king is the most valuable piece—it is illegal to play any move that puts one's king under attack by an opponent piece. A move that attacks the king must be parried immediately; if this cannot be done, the game is lost. (See {{seclink|#Check and checkmate}}.)
* A [[rook (chess)|rook]] can move any number of squares along a rank or file. A rook is involved in the king's castling move.
* A [[bishop (chess)|bishop]] can move any number of squares diagonally.
* A [[queen (chess)|queen]] combines the power of a rook and bishop and can move any number of squares along a rank, file, or diagonal.
* A [[knight (chess)|knight]] moves to any of the closest squares that are not on the same rank, file, or diagonal. (Thus the move forms an "L"-shape: two squares vertically and one square horizontally, or two squares horizontally and one square vertically.) The knight is the only piece that can leap over other pieces.
* A [[pawn (chess)|pawn]] can move forward to the unoccupied square immediately in front of it on the same file, or on its first move it can optionally advance two squares along the same file, provided both squares are unoccupied (diagram dots). A pawn can capture an opponent's piece on a square diagonally in front of it by moving to that square (diagram crosses). It {{em|cannot}} capture a piece while advancing along the same file, nor can it move to either square diagonally in front without capturing. Pawns have two special moves: the [[#Special pawn moves|''en passant'' capture]] and [[#Special pawn moves|promotion]].
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====Check and checkmate====
{{Main|Check (chess)|l1=Check|Checkmate}}
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{{Chess diagram small 
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|The black king is in [[Check (chess)|check]] by the rook.
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|White is in [[checkmate]], being unable to escape attack by the bishop on f3.
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When a king is under immediate attack, it is ''in [[Check (chess)|check]]''. A move in response to a check is legal only if it results in a position in which the king is no longer in check. There are three ways to counter a check:
* Capture the checking piece.
* Interpose a piece between the checking piece and the king (possible only if the attacking piece is a queen, rook, or bishop and there is a square between it and the king).
* Move the king to a square where it is not under attack.

The object of the game is to [[checkmate]] the opponent; this occurs when the opponent's king is in check, and there is no legal way to get it out of check. In casual games, it is common to announce "check" when putting the opponent's king in check, but this is not required by the rules of chess and is usually not done in tournaments.<ref>{{Cite book|last=United States Chess Federation.|title=U.S. Chess Federation's official rules of chess|others=Just, Tim., Burg, Daniel B.|year=2003|isbn=0-8129-3559-4|edition=5th|publisher=Random House Puzzles and Games|location=New York|oclc=52859422}}</ref>

====Castling====
{{Main|Castling}}
[[File:ChessCastlingMovie en.svg|thumb|upright=0.95|Examples of [[castling]] ([https://upload.wikimedia.org/wikipedia/commons/5/55/ChessCastlingMovie_en.svg view animation])]]
Kings can ''castle'' once per game. Castling consists of moving the king two squares toward either rook of the same color, and then placing the rook on the square that the king crossed.

Castling is possible only if the following conditions are met:<ref name="FideLawsOfChess"/>
* Neither the king nor the rook has previously moved during the game.
* There are no pieces between the king and the rook.
* The king is not in [[#Check|check]] and does not pass through or finish on a square controlled by an enemy piece.

Castling is still permitted if the rook is under attack, or if the rook crosses an attacked square. 
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====Special pawn moves====
{{Anchor|en passant}}
{{Main|En passant|Promotion (chess)|l2=Promotion}}
[[File:ChessPawnSpecialMoves.gif|thumb|right|upright=1.15|Examples of special pawn moves: ({{em|left}}) [[Promotion (chess)|promotion]]; ({{em|right}}) ''[[en passant]]'']]
Pawns have two special moves:
* ''En passant'': when a pawn makes a two-square advance to the same rank as an opponent's pawn on an adjacent file, that pawn can capture it ''en passant'' ("in passing"), moving to one square behind the captured pawn. A pawn can only be captured ''en passant'' on the turn after it makes a two-square advance. In the animated diagram, the black pawn advances two squares from g7 to g5, and the white pawn on f5 takes it ''en passant'', landing on g6.
* ''Promotion'': when a pawn advances to its {{chessgloss|eighth rank|last rank}}, it is ''promoted'' and replaced with the player's choice of a queen, rook, bishop, or knight. Usually, pawns are promoted to queens; choosing another piece is called [[underpromotion]]. In the animated diagram, the c7-pawn is advanced to c8 and promoted to a queen. If the required piece is not available (e.g. a second queen), an inverted rook is sometimes used as a substitute, but this is not recognized in FIDE-sanctioned games.
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===End of the game===

====Win====
A game can be won in the following ways:
* ''[[Checkmate]]:'' The opposing king is in check and the opponent has no legal move. (See {{seclink|#Check and checkmate}}.)
* ''[[Rules of chess#Resigning|Resignation]]:'' A player may resign, conceding the game to the opponent.<ref>{{harvp|Burgess|2000|p=481}}</ref> If, however, the opponent has no way of checkmating the resigned player, this is a draw under FIDE Laws.<ref name="FideLawsOfChess" /> Most tournament players consider it good etiquette to resign in a hopeless position.<ref>{{Cite book |title=The Right Way to Play Chess |edition=2008 revised |author=[[David Pritchard (chess player)|David Brine Pritchard]] |others=Updated by Richard James |publisher=Right Way |date=2008-11-06 |orig-date=1950 |isbn=978-0-7160-2199-5 }}</ref><ref>{{cite web|url=https://www.latimes.com/archives/la-xpm-2001-may-18-cl-64946-story.html|work=[[Los Angeles Times]]|title=Why Grandmasters Rarely Checkmate|date=2001-05-18|access-date=2020-12-03|author=Jack Peters|archive-date=29 December 2020|archive-url=https://web.archive.org/web/20201229221956/https://www.latimes.com/archives/la-xpm-2001-may-18-cl-64946-story.html|url-status=live}}</ref> 
* ''Win on time:'' In games with a [[time control]], a player wins if the opponent runs out of time, even if the opponent has a superior position, as long as the player has a theoretical possibility to checkmate the opponent were the game to continue.
* ''Forfeit:'' A player who cheats, violates the rules, or violates the rules of conduct specified for the particular tournament can be forfeited. Occasionally, both players are forfeited.<ref name="FideLawsOfChess"/>

====Draw====
There are several ways a game can end in a [[Draw (chess)|draw]]:
* ''[[Stalemate]]:'' If the player to move has no legal move, but is not in check, the position is a stalemate, and the game is drawn.
* ''[[Rules of chess#Dead position|Dead position]]:'' If neither player is able to checkmate the other by any legal sequence of moves, the game is drawn. For example, if only the kings are on the board, all other pieces having been captured, checkmate is impossible, and the game is drawn by this rule. On the other hand, if both players still have a knight, there is a highly unlikely yet theoretical possibility of checkmate, so this rule does not apply. The dead position rule supersedes an older rule which referred to "insufficient material", extending it to include other positions where checkmate is impossible, such as blocked [[Chess endgame#King and pawn endings|pawn endings]] where the pawns cannot be attacked.
* ''[[Draw by agreement]]:'' In tournament chess, draws are most commonly reached by mutual agreement between the players. The correct procedure is to verbally offer the draw, make a move, then start the opponent's clock. Traditionally, players have been allowed to agree to a draw at any point in the game, occasionally even without playing a move. More recently efforts have been made to discourage early draws, for example by forbidding draw offers before a certain number of moves have been completed, or even forbidding draw offers altogether.
* ''[[Threefold repetition]]:'' This most commonly occurs when neither side is able to avoid repeating moves without incurring a disadvantage. The three occurrences of the position need not occur on consecutive moves for a claim to be valid. The addition of the [[fivefold repetition|fivefold repetition rule]] in 2014 requires the arbiter to intervene immediately and declare the game a draw after five occurrences of the same position, consecutive or otherwise, without requiring a claim by either player. FIDE rules make no mention of [[perpetual check]]; this is merely a specific type of draw by threefold repetition.
* ''[[Fifty-move rule]]:'' If during the previous 50 moves no pawn has been moved and no capture has been made, either player can claim a draw. The addition of the [[seventy-five-move rule]] in 2014 requires the arbiter to intervene and immediately declare the game drawn after 75 moves without a pawn move or capture, without requiring a claim by either player. There are several known endgames where it is possible to force a mate but it requires more than 50 moves before a pawn move or capture is made; examples include some endgames with [[two knights endgame|two knights against a pawn]] and some [[pawnless chess endgame|pawnless endgames]] such as queen against two bishops. Historically, FIDE has sometimes revised the fifty-move rule to make exceptions for these endgames, but these have since been repealed. Some [[correspondence chess]] organizations do not enforce the fifty-move rule.{{refn|The fifty-move rule is not applied at FICGS.<ref>{{cite web |url=http://www.ficgs.com/membership.html#chess |title=50 moves rules |access-date=1 December 2009 |publisher=FICGS |url-status=live |archive-url=https://web.archive.org/web/20100209034210/http://www.ficgs.com/membership.html#chess |archive-date=9 February 2010}}</ref>|group=note}}
* ''Draw on time:'' In games with a [[time control]], the game is drawn if a player is out of time and no sequence of legal moves would allow the opponent to checkmate the player.<ref name="FideLawsOfChess"/>
* ''Draw by resignation:'' Under FIDE Laws, a game is drawn if a player resigns and no sequence of legal moves would allow the opponent to checkmate that player.<ref name="FideLawsOfChess" />

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{{Chess diagram small  
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|Black (to move) is not in check and has no legal move. The result is [[stalemate]].
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{{Chess diagram small 
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|A dead position; White's king and bishop are insufficient to deliver [[checkmate]].
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{{Chess diagram small 
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|Also a dead position; neither king can capture the other's pawns in order to promote a pawn and give checkmate.
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===Time control===
{{Multiple image
| image1            = DGT 2010 digital chess clock.ajb.jpg
| image2            = Garde Schachuhr 1.jpg
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| footer            = Typical digital and analog chess clocks
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In competition, chess games are played with a [[time control]]. Time controls are generally divided into categories based on the amount of time given to each player, which range from classical time controls, which allot about 2 hours or more to each player and which can take upwards of seven hours (even longer if [[adjournment (chess)|adjournments]] are permitted), to [[bullet chess]], in which players receive less than three minutes each. Between these are [[rapid chess]] (ten to sixty minutes per player), popular in amateur tournaments, and [[blitz chess]] (three to ten minutes), popular online. Non-classical chess is sometimes referred to as [[fast chess]].

Time is controlled using a [[chess clock]] with two displays, one for each player's remaining time. Analog chess clocks have been largely replaced by digital clocks, which allow for time controls with increments.

There are some aspects unique to online chess. A [[premove]] allows a player to submit a move on the opponent's turn, which gets played automatically if possible using little to no time. Premoves, alongside the relative ease of digital inputs, make [[ultrabullet|faster time controls]] feasible online.

Time controls are also enforced in [[correspondence chess]] competitions. A typical time control is 50 days for every 10 moves. Time is usually allotted per move in online correspondence chess.