Rules

Introduction

Chess is played on a square board of eight rows (called ranks and numbered 1 to 8) and eight columns (called files and labelled a to h) of squares. The colours of the sixty-four squares alternate and are referred to as "light squares" and "dark squares". The pieces are divided into two matching sets, by convention called White and Black. Each player, referred to by the colour of his pieces, begins the game with sixteen pieces: these comprise one king, one queen, two rooks, two bishops, two knights and eight pawns.

The colours are chosen either by a friendly agreement, by a game of chance or by a tournament director. The chessboard is placed with a light square at each player's right on the nearest rank, and the pieces are set out on the first and last two ranks as shown in the diagram. Each queen stands on a square of its own colour.

White makes the first move. The players then alternate moving one piece of their own at a time (with the exception of castling, when a rook and the king are moved simultaneously). Pieces are moved to either an unoccupied square, or one occupied by an opponent's piece, capturing it and removing it from play. With one exception (en passant), all pieces capture opponent's pieces by moving to the square that the opponent's piece occupies. When a piece can be captured on the opposing player's next move, it is said to be "threatened" or "under attack".

When a player's king is under direct attack, it is said to be in check. A player is not permitted to make any move that would place his king in check, and if his king is put in check he is then required to immediately make a move that takes the king out of check. If no such move is available, the player is checkmated. The object of the game is to checkmate the opponent.

Movements

Each chess piece has its own style of moving.

The king can move only one square horizontally, vertically, or diagonally. Once in every game, each king is allowed to make a special move, known as castling. Castling consists of moving the king two squares towards a rook, then placing the rook immediately on the far side of the king. Castling is only permissible if all of the following conditions hold:
- The player must never have moved either the king or the rook involved in castling;
- 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 squares that are under attack by enemy pieces. As with any move, castling is illegal if it would place the king in check.
- The king and the rook must be on the same rank (to exclude castling with a promoted pawn).

The rook moves any number of vacant squares vertically or horizontally (it is also involved in the king's special move of castling);

The bishop moves any number of vacant squares in any direction diagonally. Note that a bishop never changes square colour, therefore players speak about "dark-squared" or "light-squared" bishops, depending on the colour of square on which the bishop resides. Alternatively, bishops may be identified as a "queen's bishop" or a "king's bishop", depending on whether they are next to the queen or the king when on their home square.

The queen can move any number of vacant squares diagonally, horizontally, or vertically;

The knight can jump over occupied squares and moves two spaces horizontally and one space vertically or vice versa, making an "L" shape. A knight in the middle of the board has eight squares to which it can move. Note that every time a knight moves, it changes square color.

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, if both squares in front of the pawn are unoccupied. A pawn cannot move backward.
- When such an initial two square advance is made that puts that pawn horizontally adjacent to an opponent's pawn, the opponent's pawn can capture that pawn "en passant" as if it moved forward only one square rather than two, but only on the immediately subsequent move.
- Pawns are the only pieces that capture differently than 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.
- 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. In practice, the pawn is almost always promoted to a queen.

With the exception of the knight, pieces cannot jump over each other. One's own pieces ("friendly pieces") cannot be passed if they are in the line of movement, and a friendly piece can never replace another friendly piece. Enemy pieces cannot be passed, but they can be "captured". 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.[1] The king cannot be captured, only put in check. If a player is unable to get the king out of check, checkmate results, with the loss of the game.

Endings

Chess games do not have to end in checkmate - either player may resign if the situation looks hopeless. Games also may end in a draw (tie). A draw can occur in several situations, including draw by agreement, stalemate, threefold repetition of a position, the fifty move rule, or a draw by impossibility of checkmate (usually because of insufficient material to checkmate).

Timing

Besides casual games without exact timing, chess is also played with a time control, mostly by club and professional players. This involves measuring each player's cumulative total of time taken to move. If a player's time runs out before the game is completed, he automatically loses. The timing ranges from long games played up to seven hours to shorter rapid chess games lasting usually 30 minutes or one hour per game. Even shorter is blitz chess with a time control of three to fifteen minutes for each player and bullet chess (under three minutes).

FIDE rules

The international rules of chess are described in more detail in the FIDE Handbook, section Laws of Chess (FIDE Handbook).