If an opponent searched their library this turn, you may payrather than pay this spell's mana cost.
Target opponent puts the top thirteen cards of their library into their 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.
10/1/2009 Archive Trap checks only whether an opponent searched their library. It doesn’t matter whether that player found a card during the search.
10/1/2009 A spell or ability causes a player to search their library only if it specifically contains the word “search” in its text. For example, if a spell or ability lets a player look at the top four cards of their library and do something with one of those cards, that’s not a search.
10/1/2009 If a search effect is affected by Aven Mindcensor’s ability (which causes a player to search the top four cards of their library instead), that still counts as searching that library.
10/1/2009 The opponent you target doesn’t have to be the opponent who searched their library.
10/1/2009 If the targeted opponent has fewer than thirteen cards in their library, that player puts their entire library into their graveyard.