Epic Experiment is a special Sorcery card from Time Spiral Remastered (TSR), collector number 376. Current market price: $0.52 (foil $2.34), TCGplayer market prices via Scryfall.
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.