This trick very easy, yet it amuses even clever people. It can be used for all kinds of prediction tricks involving cards, depending on the magician's innovation.
The magician writes down a card on a piece of paper. The paper is then folded and handed over to a spectator. The magician then takes a pack of cards and shows that it is only a normal pack. He then shuffles the pack and asks the spectator to make a cut. The cut pack of cards is turned over the rest of the cards.