High Quality Content by WIKIPEDIA articles! A rook ( borrowed from Persian rokh, Sanskrit rath, "chariot") is a piece in the strategy board game of chess. In the past the piece was called the castle, tower, marquess, rector, and comes (Sunnucks 1970), and non-players still often call it a "castle".[1] Using the rook in a specialized double-movement with the king is still refered to as castling. Each player starts with two rooks, one in each of the corners nearest their own side.