The magician explains that he has made a prediction of an event yet to happen. He shows an envelope containing this prediction. Any spectator from the audience is invited to deal through a deck of cards face up, one at a time. The spectator may stop dealing at any time, or change his mind and continue dealing.
When the person is satisfied that he has randomly selected a card, the envelope is immediately opened to reveal a single card to be the matching card! Totally self-contained; has about a two minute learning time.