A pawn that reaches a player's eighth or ninth ranks can elect to either promote or remain a pawn, but it "must" promote upon reaching the tenth rank. Unlike standard chess, a pawn may be promoted only to a captured piece of the same colour. (So, it is impossible for either side to own two queens, or two marshals, or three rooks, etc.) If, and for as long as, no captured piece is available to promote to, a pawn on a player's ninth rank must stay on the ninth rank, but it can still give check.