The World Chess Federation, which is officially known as FIDE, an acronym for Federation Internationale des Echecs, is responsible for the official chess rules, also called laws of chess. These rules govern the basic movements of the pieces, the equipment used and the conduct of players at world competitions. As of 2015, the official laws of chess are those adopted at the 84th FIDE Congress, implemented in July 2014.
The norms for the basic movements of chess have not substantially changed since the 19th century. Chess is a two-players game, with a goal to checkmate the opponent's king and win the game. A player checkmates if she can capture the opponent's king with one of her pieces, and the opponent cannot legally move the king. If neither player can checkmate the opponent's king, the game is drawn.
There are two sets of 16 pieces each; one set is black and the other is white. Each player starts the game with one of these sets, which contain eight pawns, two knights, two bishops, two rooks, a queen and a king. The pieces are displayed on the chessboard, and each player takes turns to move one piece to any other square on the chessboard that is not occupied by a piece of the same color. If a player moves a piece to a square that was occupied by a piece of the other color, she captures the latter piece, taking it out of the game. The FIDE official chess rules also regulate how to proceed at chess competitions, including the use of the chessclock, the role of the arbiter and the recording of the moves.