Promotion (chess)

Promotion is a chess rule that a pawn that reaches its eighth rank is immediately changed into the player's choice of a queen, knight, rook, or bishop of the same color. The new piece replaces the pawn on the same square, as part of the same move. The choice of new piece is not limited to pieces that have already been captured; it is legal for promotion to result in a player controlling, for example, two Queens of the same color despite starting the game with one. Promotion is immediate and mandatory for any pawn that reaches its eighth rank, and the pawn may not remain a pawn. Pawn promotion, or the threat of it, often decides the result of a chess endgame.