If an opponent had three or more cards put into their graveyard from anywhere this turn, you may payrather than pay this spell's mana cost.
Exile all cards from target player's graveyard.
10/1/2009 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.
10/1/2009 Casting a Trap by paying its alternative cost doesn’t change its mana cost or converted mana cost. The only difference is the cost you actually pay.
10/1/2009 Effects that increase or reduce the cost to cast a Trap will apply to whichever cost you chose to pay.