Rook (chess) of a fifth daughter. Unicode defines two codepoints for rook: ♖ U+2656 White Chess Rook (HTML ♖) ♜ U+265C Black Chess Rook (HTML ♜) Rook (chess) A rook (; ♖,♜) is a piece in the strategy board game of chess. Formerly the piece (from Persian رخ "rokh"/"rukh") was called the "tower", "marquess", "rector", and "comes" . The term "castle" is considered informal, incorrect, or old-fashioned. Each player starts the game with two rooks, one on each of the corner squares on their own side of the board. The white rooks start on squares a1 and h1, while the black rooks
Chess and is provably less than 10, with a game-tree complexity of approximately 10. The game-tree complexity of chess was first calculated by Claude Shannon as 10, a number known as the Shannon number. Typically an average position has thirty to forty possible moves, but there may be as few as zero (in the case of checkmate or stalemate) or (in a constructed position) as many as 218. Chess has inspired many combinatorial puzzles, such as the knight's tour and the eight queens puzzle. The idea of creating a chess-playing machine dates to the 18th century; around 1769, the chess-playing automaton