If an opponent had three or more cards put into their graveyard from anywhere this turn, you may pay {0} rather than pay this spell's mana cost. Exile all cards from target player's graveyard.
2009-10-01
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.
2009-10-01
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.
2009-10-01
Effects that increase or reduce the cost to cast a Trap will apply to whichever cost you chose to pay.