結界
在你的維持開始時,展示你的牌庫頂牌。 若該牌為生物牌,且與由你操控的一個生物有共通的生物類別,則你可以施放該牌,且不需支付其魔法力費用。若否,將該牌置於你的牌庫底。
If you cast a card "without paying its mana cost," you can't pay any alternative costs. You can pay additional costs, such as kicker costs. If the card has mandatory additional costs, you must pay those.