Once in every game, each king is allowed to make a special move, known as castling.Castling consists of moving the king two squares along the first rank toward a rook (which is on the player's first rank When a pawn advances two squares from its starting position and there is an opponent's pawn on an adjacent file next to its destination square, then the opponent's pawn can capture it en passant (in passing), and move to the square the pawn passed over.

FIDE also organizes the Women's World Championship, the World Junior Championship, the World Senior Championship, the Blitz and Rapid World Championships, and the Chess Olympiad, a popular competition among international teams.

FIDE is a member of the International Olympic Committee, which can be considered as a recognition of chess as a sport;) also recognize chess as a sport. There is also a Correspondence Chess World Championship and a World Computer Chess Championship.

This can only be done on the very next move, otherwise the right to do so is forfeit.

For example, in the animated diagram, the black pawn advances two squares from g7 to g5, and the white pawn on f5 can take it via en passant on g6 (but only on White's next move).

The rise of strong computer programs (called "engines") runnable on hand-held devices has led to increasing concerns about cheating during tournaments.

There are many variants of chess that utilize different rules, pieces, or boards.The pieces are set out as shown in the diagram and photo, with each queen on a square of its own color, the white queen on a light square and the black queen on a dark.The player with the white pieces always moves first.By convention, the game pieces are divided into white and black sets, and the players are referred to as White and Black respectively.Each player begins the game with 16 pieces of the specified color, which consist of one king, one queen, two rooks, two bishops, two knights, and eight pawns.A player cannot "pass"; at each turn one must make a legal move (this is the basis for the finesse called zugzwang).