[ECO code B07]
Black's King on K1(e8) is forced to exchange queens and forfeits all privilege of castling in the game, giving White a slight advantage.
White Black 1. P-Q4 P-Q3 2. P-K4 P-K4 3. PxP PxP 4. QxQ ch KxQ fcd
Example ends: Undo or Jump or Clear