The warlock goes ended a deck of cards and has a Onlooker honour any card. While using this patter, double-lift the chosen card (now on top of the deck) to show that its back is blue while the rest of the pack is red. In actuality, the blue back belongs to your replaced card, not his.6.
Instructions
1. To prepare, remove one card from the blue-backed deck and place it on the bottom of the red-backed deck. Additionally, take the card of the same value from the red-backed deck and place it on the bottom of the blue deck.
Leave the blue deck on the table.
2. Spread the red deck face up and have the spectator choose any card. Whichever card he chooses, split the face-up deck in two, being sure to keep your replaced card on top of one of the piles.
3. While you remind the spectator that his choice was completely random, deal the chosen card right on top of the blue-backed card. In one fell swoop, reassemble the pack by placing the right-hand packet on top of the left. This leaves the spectator's card right on top of the replaced, different color card.
4. Remind the spectator once again that he could have selected any card in the deck. This serves as patter.
5. The wizard removes this card from the pack and turns it face down, showing it has a blue back. He spreads the rest of the deck face down to show that the deck is all red-backed. He then spreads a second deck, all with blue backs, to show that only one card has a red back-the card with the same value and suit that the spectator chose. Now let's try it.
Explain that you knew all along what card would be chosen. To prove it, take the blue deck just sitting there on the table and add the double card (his chosen card on top of the real blue card) to the deck.
7. Spread the blue deck face down to show one red-backed card. Turn it over to show his chosen card in red, not blue. In actuality, you're taking the actual card he chose and inserting it into the new deck, but because of the double-lift, he thinks his card originally had a blue back.
