Whenever Scion of Opulence or another nontoken Vampire you control dies, create a Treasure token. (It’s an artifact with “, Sacrifice this artifact: Add one mana of any color.”) , Sacrifice two artifacts: Exile the top card of your library. You may play that card this turn.
Playing a card this way follows all the normal timing rules for that card. For example, if you play a land this way, you may do so only during your main phase while the stack is empty and only if you haven't yet played a land (unless another effect allows you to play additional lands).
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.