- Promotion is mandatory for a pawn reaching the last rank. However, they can only
- promote into a friendly piece captured (which is back on the board). If none is
- available, the promotion on last rank is impossible and the pawn cannot move
- (but still gives check).
+ Promotion is mandatory for a pawn reaching the last rank. However, they can
+ only promote into a friendly piece captured (which is back on the board).
+ If none is available, the promotion on last rank is impossible and the pawn
+ cannot move (but still gives check).