After moving one of their own pieces, a player must move one of the opponent's pawns forward one square.
Rules are as normal chess except that after making a legal move, a player must move one of the opponent's pawns exactly one square straight forward (i.e. towards the player) to complete the turn, if possible.
Capturing with an opponent's pawn is not permitted.
If an opponent's pawn is moved to promotion, then the opponent chooses to what piece it promotes; if the promotion gives check, the opponent wins the game.
If every legal pawn move forward gives check, then the opponent wins immediately, even if the player checked or mated the opponent previously that same turn.