Wrong rook pawn

A rook pawn is a pawn on either edge file, named for starting in front of a rook. It becomes a wrong rook pawn when its promotion square is on the color that the attacking bishop can never control.

The classic consequence appears in king, bishop, and rook pawn versus king. If the defending king reaches the corner where the pawn must promote, the bishop cannot drive it out because the bishop travels only on the other color. The attacking king also cannot stand next to the enemy king. Despite being a bishop and pawn ahead, the attacker may have no way to progress, so the game is drawn.

The pawn is not wrong in every position. The defense depends on the king reaching the safe corner and on no other material changing the problem. The term describes the mismatch between the pawn and the wrong bishop, not a permanent defect in the pawn. The motif can also arise in some opposite-colored bishop endings.