ソーサリー
協約
あなたのライブラリーからカード1枚を探し、裏向きで追放する。その後、ライブラリーを切り直す。この呪文が協約されているなら、その追放されたカードを、それの呪文としてのマナ総量が4以下であるなら、マナ・コストを支払うことなく唱えてもよい。これによりそれを唱えなかったなら、その追放されたカードをあなたの手札に加える。
Bargain means "As an additional cost to cast this spell, you may sacrifice an artifact, enchantment, or token."
Bargain represents an optional additional cost. A spell cast with that additional cost paid is "bargained."
Some instant and sorcery spells require additional targets if they're bargained. You ignore those targeting requirements if those spells aren't bargained, and you can't bargain those spells unless you can choose the appropriate targets. On the other hand, you can bargain a permanent spell even if you won't be able to choose targets for an enters-the-battlefield ability of that permanent once the spell resolves.
If you copy a bargained spell, the copy is also bargained. If a card or token enters the battlefield as a copy of a permanent that's already on the battlefield, the new permanent isn't bargained, even if the original was.
You may sacrifice only one artifact, enchantment, or token to pay a spell's bargain cost.