Pawn

The pawn may move forward to the unoccupied square immediately in front of it on the same file; or on its first move it may advance two squares along the same file provided both squares are unoccupied; or it may move to a square occupied by an opponent's piece which is diagonally in front of it on an adjacent file, capturing that piece. The pawn has two special moves: the en passant capture and pawn promotion.