Castling is a move in the game of chess involving a player’s king and either of the player’s original rooks. It is the only move in chess in which a player moves two pieces in the same move.
Castling consists of moving the king two squares towards a rook on the player’s first rank, then moving the rook to the square that the king crossed. Castling may be done only if the king has never moved, the rook involved has never moved, the squares between the king and the rook involved are unoccupied, the king is not in check, and the king does not cross over or end on a square attacked by an enemy piece. Castling is one of the rules of chess and is technically a king move .