Inevitable (DVD and Gimmicks) by Brian Caswell & Alakazam Magic - Tricks Specify Red or Blue Back
In this effect the behaviour of a spectator is predicted not once, but three times over. Your spectator examines a blank faced deck of cards. On six of the cards you have drawn symbols - two cards with a circle, two with a square and two with a cross.
She observes you position three different symbols cards at various locations inside the pack of blank cards. The deck is then turned face down and she is asked to position the matching three symbol cards face down at various places in the deck. She is given complete freedom where she places her three cards.
This completed, you explain that you are not now going to pick up the deck and do a lot of jiggery pokery or sleight of hand with it, because this is not a trick. We like to think our actions are under our control, or at least maybe just random. But actually our behaviour is curiously predictable.
You simply turn the deck face up and spread the cards across the table. Each time she placed a symbol right next to one of yours. But not only that, astonishingly, each of the pairs match precisely.
This version of the card matching effect has a number of points to recommend it. Three matches make a big effect, the ESP symbols give a strong mentalism feel, you are completely clean at the end, there is no tell-tale evidence that the effect was anything other than entirely genuine, there are no gaffs of any type, it's easy to do, and the only requirements are a blank deck and a marker pen to draw on the symbols.
Comes complete with an instructional DVD and custom printed ESP cards. Add your own deck or blank faced deck!