Scarlet Deception

The deck is shuffled, the spectator decides how many cards they wanna use and what cards they wanna use. Through a very fair procedure, you deal the cards in two piles, one for you, one for them, with the face up, no sneaky business. You grab your pile and continue, until you have ONLY one card and your card is the only one with a different back. Easy to perform, and requires just a little bit of sleight of hands.