Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent’s king. It is sometimes called international chess or Western chess to distinguish it from related games, such as xiangqi (Chinese chess) and shogi (Japanese chess). The recorded history of chess goes back at least to the emergence of a similar game, chaturanga, in seventh-century India. The rules of chess as we know them today emerged in Europe at the end of the 15th century, with standardization and universal acceptance by the end of the 19th century. Today, chess is one of the world’s most popular games, played by millions of people worldwide.
Chess is an abstract strategy game that involves no hidden information and no use of dice or cards. It is played on a chessboard with 64 squares arranged in an eight-by-eight grid. At the start, each player controls sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns. White moves first, followed by Black. Checkmating the opponent’s king involves putting the king under immediate attack (in “check”) whereby there is no way for it to escape. There are also several ways a game can end in a draw.
Organized chess arose in the 19th century. Chess competition today is governed internationally by FIDE (the International Chess Federation). The first universally recognized World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; Ding Liren is the current World Champion. A huge body of chess theory has developed since the game’s inception. Aspects of art are found in chess composition, and chess in its turn influenced Western culture and art, and has connections with other fields such as mathematics, computer science, and psychology.
One of the goals of early computer scientists was to create a chess-playing machine. In 1997, Deep Blue became the first computer to beat the reigning World Champion in a match when it defeated Garry Kasparov. Today’s chess engines are significantly stronger than the best human players and have deeply influenced the development of chess theory.
Chess pieces are divided into two different colored sets. While the sets might not be literally white and black (e.g. the light set may be a yellowish or off-white color, the dark set may be brown or red), they are always referred to as “white” and “black”. The players of the sets are referred to as White and Black, respectively. Each set consists of sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns. Chess sets come in a wide variety of styles; for competition, the Staunton pattern is preferred.
The game is played on a square board of eight rows (called ranks) and eight columns (called files). By convention, the 64 squares alternate in color and are referred to as light and dark squares; common colors for chessboards are white and brown, or white and dark green.
Each piece has its own way of moving. In the diagrams, the crosses mark the squares to which the piece can move if there are no intervening piece(s) of either color (except the knight, which leaps over any intervening pieces). All pieces except the pawn can capture an enemy piece if it is on a square to which they would be able to move if the square were unoccupied.
The king moves one square in any direction. There is also a special move called castling that involves moving the king and a rook. The king is the most valuable piece—attacks on the king must be immediately countered, and if this is impossible, the game is immediately lost (see Check and checkmate below).
A rook can move any number of squares along a rank or file, but cannot leap over other pieces. Along with the king, a rook is involved during the king’s castling move.
A bishop can move any number of squares diagonally, but cannot leap over other pieces.
A queen combines the power of a rook and bishop and can move any number of squares along a rank, file, or diagonal, but cannot leap over other pieces.
A knight moves to any of the closest squares that are not on the same rank, file, or diagonal. (Thus the move forms an “L”-shape: two squares vertically and one square horizontally, or two squares horizontally and one square vertically.) The knight is the only piece that can leap over other pieces.