Exile the top X cards of your library. You may cast instant and sorcery spells with mana value X or less from among them without paying their mana costs. Then put all cards exiled this way that weren't cast into your graveyard.
"One need not know the specific details of a spell to suppress its effect. Simply rearrange the rules of the reality within which the spell operates."
—Imbraham, Quandrix dean