Chess

Chess (English: Chess, Arabic: شطرنج) is a strategy game played by two people on a board of 64 squares alternating between black and white. Each player begins with 16 pieces: a king, a queen, two bishops, two knights (called by different names in some languages), two rooks, and eight pawns. The primary objective is to reach a condition called 'checkmate', in which the opponent's king is under attack with no means of escape.

The game is based on calculation and planning: each player attempts to move their pieces effectively, control the centre of the board, and create opportunities to shift the course of play in their favour. Play proceeds in turns: one player moves, then the other.

History

The game is said to have originated in India, where it existed as a game called chaturanga. It later passed to Persia, where the name 'shatranj' derives from, and then spread through the Islamic world. In the Middle Ages it reached Europe, where the rules were altered: the power of the queen and bishop was increased, making the game faster. The modern form of the rules was established in the later centuries of European medieval period.

Rules and moves

Each piece has its own manner of moving: the rook moves in straight lines (ranks and files), the bishop moves diagonally, the queen can move in both ways, and the knight moves in an 'L' shape and can jump over other pieces. The pawn advances forward but captures diagonally; if it reaches the furthest rank it transforms into another piece, usually a queen. There are also special moves such as castling (an exchange of moves between king and rook) and en passant.

The game can end in victory (checkmate), a draw when no legal move remains but the king is not under attack (stalemate), agreement between both sides, repetition of the same position, or time expiration when a clock is used.

Competition and rating

Chess is governed by the world federation FIDE, which certifies world champions and sets tournament rules. The skill of players is measured by a point-based system (Elo), while titles such as Grandmaster and International Master are awarded on the basis of achieved results at qualifying levels.

Computers

Chess computer programs have become an important tool for learning and analyzing the game. Since the late 20th century, machines have reached a level superior to the strongest players, which has changed how the game is prepared in opening and endgame phases. Modern programs use machine learning.