Rules of chess

Movement

Basic moves
Each type of chess piece has its own method of movement. A piece moves to a vacant square except when capturing an opponent's piece.
Except for any move of the knight and castling, pieces cannot jump over other pieces. A piece is captured (or taken) when an attacking enemy piece replaces it on its square (en passant is the only exception). The captured piece is thereby permanently removed from the game. The king can be put in check but cannot be captured.

The king moves exactly one square horizontally, vertically, or diagonally. A special move with the king known as castling is allowed only once per player, per game.

A rook moves any number of vacant squares in a horizontal or vertical direction. It also is moved when castling.

A bishop moves any number of vacant squares in any diagonal direction.

The queen moves any number of vacant squares in a horizontal, vertical, or diagonal direction.

A knight moves to the nearest square not on the same rank, file, or diagonal. (This can be thought of as moving two squares horizontally then one square vertically, or moving one square horizontally then two squares vertically—i.e. in an "L" pattern.) The knight is not blocked by other pieces: it jumps to the new location.

Pawn have the most complex rules of movement:
A pawn moves straight forward one square, if that square is vacant. If it has not yet moved, a pawn also has the option of moving two squares straight forward, provided both squares are vacant. Pawns cannot move backwards.
Pawns are the only pieces that capture differently from how they move. A pawn can capture an enemy piece on either of the two squares diagonally in front of the pawn (but cannot move to those squares if they are vacant).
The pawn is also involved in the two special moves en passant and promotion.

Castling
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.[2] 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.

En passant (Pass Pawn)
Three images showing en passant. First, a white pawn moves from the a2-square to a4; then, the black pawn moves from b4 to a3; finally, the white pawn on a4 is removed
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 rank, 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 (converted) to a queen, rook, bishop, or knight of the same color at the choice of the player (a queen is usually 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 of their pawns are promoted. If the desired piece is not available, the player should call the arbiter 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 (it is pinned against its own king) may still deliver check to the opposing player.
A player may not make any move which places or leaves his king in check. The possible ways to get out of check are: * Move the king to a square where it is not threatened. * Capture the threatening piece (possibly with the king). * Block the check by placing a piece between the king and the opponent's threatening piece.
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.

Competition rules
These rules apply to games played "over the board". There are special rules for correspondence chess, blitz chess, computer chess, and for handicapped players.

Act of 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 move is illegal. 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 captured 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.[5] If the player touches the rook at the same time as touching the king, 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 game clock. Each player must make his moves within the time control or forfeit the game. There are different types of time controls. In some cases each player will have a certain amount of time to make a certain number of moves. In other cases each player will have a limited amount of time to make all of his moves. Also, the player may gain a small amount of additional time for each move made, either by a small increment added for each move made, or by the clock delaying a small amount of time each time it is started after the opponent's move. * If a player delivers a checkmate, the game is over and that player wins, no matter what is subsequently noticed about the time on the clock. * If player A calls attention to player B being out of time while player A is not out of time and some sequence of legal moves leads to B being checkmated then player A wins automatically. * If player A does not have the possibility of checkmating B then the game is a draw.

There are various rates of play in use. The following indicates the different options available:

Blitz has typical time limits of 5 minutes for each player for all of the moves.
Rapidplay is played with typical time limits of 30 minutes for each player for all the moves.
Local league chess has typical time controls of 35 moves in 75 minutes and then perhaps 15 or 20 minutes to finish the game.
International chess has a standard time control of 40 moves in 2 hours and then an extra hour to reach move 60. After this, if the game is still in progress a quickplay finish decides the game.

With the use of digital clocks it is common to play with an increment such as 2 12. This means that each person has 2 minutes to make their moves and on each move they make 12 seconds is added to the time they have remaining on the clock. Increments can also be used for longer games.

Clock Tips

There are some things to bear in mind when using a clock:
1. Always remember to press your clock after you have moved.
2. Don't forget to check whether your opponent has lost on time. It is the responsibility of the player to point out that his opponent has lost on time.
3. Press the clock with the same hand with which you have moved the piece. It is against the rules to keep a finger on the button or to hover over it.
4. You must not pick up the clock or punch it forcibly. This can lead to you forfeiting the game.
5. Keep score carefully so that you know when you have reached the time control.
6. Make sure you know what the time limit is before you start to play!

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, the king is never actually captured or removed from the board because checkmate ends the game.
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. This normally happens when the player believes he or she is very likely to lose the game. A player may resign by saying it verbally or by indicating it on their scoresheet in any of three ways: (1) by writing "resigns", (2) by circling the result of the game, or (3) by writing "1–0" if Black resigns or "0–1" if White resigns (Schiller 2003:21). Tipping over the king also indicates resignation, but it is not frequently used (and should be distinguished from accidentally knocking the king over). 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.

Draws
The game ends in a draw if any of these conditions occur:

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.
The game is immediately drawn when there is no possibility of checkmate for either side with any series of legal moves. This draw is often due to insufficient material, including the endgames * king against king; * king against king and bishop; * king against king and knight; * king and bishop against king and bishop, with both bishops on squares of the same color.
Both players agree to a draw after one of the players makes such an offer.

The player having the move may claim a draw by declaring that one of the following conditions exists, or by declaring an intention to make a move which will bring about one of these conditions:
Fifty-move rule: There has been no capture or pawn move in the last fifty moves by each player.
Threefold repetition: The same board position has occurred 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.

If the claim is proven true, the game is drawn.

At one time, if a player was able to check the opposing king continually (perpetual check) 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.

Time control
A game played under time control will end as a loss for a player who uses up all of their allotted time, unless the opponent cannot possibly checkmate him (see the Timing section above). 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.