Promotion rank

The promotion rank is the horizontal row farthest from a pawn's initial side. For White's pawns it is rank 8; for Black's pawns it is rank 1. The board has eight ranks, numbered from White's starting side.

When a pawn reaches that rank by advancing or capturing, it must immediately become a queen, rook, bishop, or knight. It may not remain a pawn or postpone the choice. The promoted piece begins controlling squares as soon as the exchange is completed.

The promotion rank contains eight squares. The exact destination reached by the pawn is called the promotion square. This distinction matters in endgames: a pawn advancing on a rook file reaches a corner square; if it captures earlier and changes files, it can reach another square on the same rank.