The rook (; ♖, ♜) is a piece in the game of chess. It may move any number of squares horizontally or vertically without jumping, and it may an enemy piece on its path; additionally, it may participate in castling. Each player starts the game with two rooks, one in each corner on their own side of the board. Formerly, the rook (from Persian رخ rokh/rukh, meaning "chariot") was alternatively called the tower, marquess, rector, and comes (count or earl). The term "castle" is considered to be informal, incorrect, or old-fashioned. Placement and movement The white rooks start on the squares a1 and h1, while the black rooks start on a8 and h8. The rook moves horizontally or vertically, through any number of unoccupied squares. The rook cannot jump over pieces. The rook may capture an enemy piece by moving to the square on which the enemy piece stands, removing it from play. The rook also participates with the king in a special move called castling, wherein it is transferred to the square crossed by the king after the king is shifted two squares toward the rook. Strategy Relative value The rook is worth about five pawns. In general, rooks are stronger than bishops or knights and are considered greater in value than either of those pieces by nearly two pawns, but less valuable than two minor pieces by approximately a pawn. Two rooks are generally considered to be worth slightly more than a queen (see chess piece relative value). Winning a rook for a bishop or knight is referred to as winning the exchange. Rooks and queens are called major pieces or heavy pieces, as opposed to bishops and knights, the minor pieces. Development In the opening, the rooks are blocked in by other pieces and cannot immediately participate in the game, so it is usually desirable to connect one's rooks on the by castling and then clearing all pieces except the king and rooks from the first rank. In that position, the rooks support each other and can more easily move to occupy and control the most favorable . A common strategic goal is to a rook on the first rank of an open file (i.e., one unobstructed by pawns of either player) or a half-open file (i.e., one unobstructed by friendly pawns). From this position, the rook is relatively unexposed to risk but can exert control on