インスタント — 罠
3体以上のクリーチャーが攻撃している場合、あなたは無気力の罠のマナ・コストを支払うのではなく、

を支払ってもよい。
攻撃しているクリーチャーはターン終了時まで-3/-0の修整を受ける。
Effects that increase or reduce the cost to cast a Trap will apply to whichever cost you chose to pay.
Casting a Trap by paying its alternative cost doesn't change its mana cost or mana value. The only difference is the cost you actually pay.
You may ignore a Trap's alternative cost condition and simply cast it for its normal mana cost. This is true even if its alternative cost condition has been met.