When responder raises a preempt below game, whether competitively or not, and an opponent overcalls, opener may not bid and there is no special agreement over whether he may double.

• 当应叫者对阻击开叫加叫但未成局时,不管是否为竞叫场合,若敌方再叫牌,开叫者可能不叫牌,但是否可能加倍则没有约定。