The rules of chess

This article is an excerpt of the number one chess website bestofchess. Chess rules, the laws of chess:

The rules of chess are set by The  the World Chess Organization (FIDE), with some modifications made 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 people on a chessboard, with sixteen pieces (of six types) for each player. Each type of piece moves in a distinct way. The goal of the game is to checkmate, that is, to threaten the opponent’s king with inevitable capture. Games do not necessarily end with checkmate – players often resign if they believe they will lose. In addition, there are several ways that a game can end in a draw.

Setup of chessboard:

The chessboard is a square board divided into 64 squares of alternating color. 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 ranks and vertical rows are called files.
Each player controls sixteen pieces:Each player begins the game with sixteen pieces: 1 king, 1 queen, 2 bishops, 2 knights, 2 rooks, and 8 pawns.
At the beginning of the game, the pieces are arranged as shown in the picture: The pieces are placed, one on a square, as follows:
The rooks are placed on the outside corners, right and left edge.
The knights are placed immediately inside of the rooks.
The bishops are placed immediately inside of the knights.
The queen is placed on the central square of the same color of that of the player: white queen on the white square and black queen on the black square.
The king takes the vacant spot next to the queen.
The 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. 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 such as Round-robin tournament or Swiss system tournament 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 reveal their color. Play then commences with white.

Movement of each piece:

First of all, we should mention that white always moves first. After the first move, players move by alternance one piece per turn. Pieces are moved to either an unoccupied square or one occupied by an opponent’s piece, which is captured and removed from play. With the sole exception of en passant, all pieces capture opponent’s pieces by moving to the square that the opponent’s piece occupies. A player may not make any move that would put or leave his or her king under attack. If the player to move has no legal moves, the game is over; it is either a checkmate if the king is under attack, or a stalemate (a draw) if the king is not.

The king moves:

The king moves one square in any direction. The king has also a special move which is called castling and involves also moving a rook.

The rook moves:

The rook can move any number of squares along any rank or file, but may not leap over other pieces. Along with the king, the rook is involved during the king’s castling move.

The bishop moves:

The bishop can move any number of squares diagonally, but may not leap over other pieces.

The queen moves:

The queen can move any number of squares along rank,file, or diagonal, it combines the power of the rook and bishop, but it may not leap over other pieces as the knight can do.

The knight moves:

The 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.

The pawn moves:

The pawn may move forward to the unoccupied square immediately in front of it on the same file, or on its first move it may advance two squares along the same file provided both squares are unoccupied; or the pawn may capture an opponent’s piece on a square diagonally in front of it on an adjacent file, by moving to that square. The pawn has two special moves: the en passant capture and pawn 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.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

If player A’s pawn moves forward two squares and player B has a pawn on his fifth rank on an adjacent file, B’s pawn can capture A’s pawn as if A’s pawn had moved only one square. This capture can only be made on the immediately subsequent move. In this example, if the white pawn moves from a2–a4, the black pawn on b4 can capture it en passant, ending up on a3.

Pawn promotion

If a pawn advances 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 (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.

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 picture 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; it cannot capture the queen, because it would then be threatened 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: by writing “resigns”,  by circling the result of the game, or by writing “1–0″ if Black resigns and “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 .

Draws

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

• The result 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 picture 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 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.

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 .
The United States Chess Federation (USCF) 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.
If a player is out of time and also calls attention to his opponent running out of time, then:
If a sudden death time control is not being used, the game continues in the next time control period .
if the game is played under a sudden death time control, then if it can be established which player ran out of time first, the game is lost by that player; otherwise the game is drawn .
If a player believes that his opponent is attempting to win the game on time and not by normal means (i.e. checkmate), if it is a sudden death time control and the player has less than two minutes remaining, the player may stop the clocks and claim a draw with the arbiter. The arbiter may declare the game a draw or postpone the decision and allot the opponent two extra minutes.

Read the full chess rules article here: chess rules.