Chess (the "Game of Kings") is a board game for two players, which requires 32 chesspieces (or chessmen) and a board demarcated by 64 squares. Gameplay does not involve random luck; consisting solely of strategy, (see also tactics, and theory). Chess is one of humanity's more popular games; it is has been described not only as a game, but also as both art and science. Chess is sometimes seen as an abstract wargame; as a "mental martial art".
The number of legal positions in chess is estimated to be between 1043 and 1050, and the game-tree complexity approximately 10123, while there are 0 (=(stale)mate) to 218 possibilities per move. Chess is played both recreationally and competitively in clubs, tournaments, on-line, and by mail (correspondence chess).
Many variants and relatives of chess are played throughout the world; amongst them, the most popular are Xiangqi (China), Buddhi Chal (Nepal) and Shogi (Japan), all of which come from the same historical stem as chess.