Chess is a two-player game, where one player is assigned white pieces and the other black. Each player has 16 pieces to start the game: one king, one queen, two rooks, two bishops, two knights and eight pawns.

The object of the game is to capture the other player's king. This capture is never actually completed, but once a king is under attack and unable to avoid capture, it is said to be checkmated and the game is over.

The game is started in the position shown below on a chess board consisting of 64 squares in an 8x8 grid. The White player moves first. Then each player takes a single turn. In fact, a player must move in turn. In other words a move cannot be skipped.

A move consists of placing one piece on a different square, following the rules of movement for that piece.

A player can take an opponent's piece by moving one of his or her own pieces to the square that contains an opponent's piece. The opponent's piece is removed from the board and is out of play for the rest of the game.

If a King is threatened with capture, but has a means to escape, then it is said to be in check. A King cannot move into check, and if in check must move out of check immediately. There are three ways you may move out of check:

The primary objective in chess is to checkmate your opponent's King. When a King cannot avoid capture then it is checkmated and the game is immediately over.

The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in 'stalemate'. This immediately ends the game.

A regular chess clock is used to limit the length of a game. These clocks count the time that each player separately takes for making his own moves. The rules are very simple, if you run out of time, you lose the game, and thus must budget your time.

If the necessary conditions are met, a king and rook can move simultaneously in a castling move. The conditions are as follows:

When castling, the king moves two squares toward the rook, and the rook moves over the king to the next square; i.e., white's king on e1 and rook on a1 move to: king c1, rook d1 (long castling); white's king on e1 and rook on h1 move to: king g1, rook f1 (short castling). The move is similar for black.

A pawn, attacking a square crossed by an opponent's pawn which has [just] been advanced two squares in one move from its original square, may capture this opponent's pawn as though the latter had been moved only one square. This capture may only be made in [immediate] reply to such an advance, and is called an "en passant" capture.

On reaching the last rank, a pawn must immediately be exchanged, as part of the same move, for [either] a queen, a rook, a bishop, or a knight, of the same color as the pawn, at the player's choice and without taking into account the other pieces still remaining on the chessboard. The effect of the promoted piece is immediate and permanent!

The game is won by the player

The game is drawn when the king of the player who has the move is not in check, and this player cannot make any legal move. The player's king is then said to be "stalemated". This immediately ends the game.

The game is drawn upon agreement between the two players.

The game is drawn when one of the following endings arises:

The player to move can claim a draw if

The game is lost by a player who has not completed the prescribed number of moves in the allotted time, unless his opponent has only the king remaining, in which case the game is drawn.

The king is the most important piece on the chessboard. The king may move one square in any direction, including diagonally (except for castling). It can never be captured and if it is in danger then it must be made safe immediately. If it is not possible to make the king safe then the game is lost. When they are attacked by a piece of the opponent, it is called check, and when in a check that cannot be removed, they are checkmated, and the game is lost for their owner.

The queen is the most powerful piece on the board. This is because it can control more squares than any other chessman. It moves straight forward or backwards and diagonally any number of squares. However, it cannot jump over other pieces.

The rook moves any number of squares horizontally or vertically, but it cannot jump over other pieces.

The bishop moves to any square on the diagonals on which it stands. However, it is not allowed to jump over other pieces.

The knight's move is composed of two different steps; first, it makes one step of one single square along its rank or file, and then, still moving away from the square of departure, one step of one single square on a diagonal. It does not matter if the square of the first step is occupied.

The pawn normally moves only forward.

First move

It advances from its original square either one or two vacant squares along the file on which it is placed, and on subsequent moves it advances one vacant square along the file.

Capturing

it advances one square along either of the diagonals on which it stands.