While your back is turned, a spectator deals cards off a deck that THEY shuffled while you wait for them to reach a card that you ‘sense’ might be near their card. Then they are asked to deal a few cards from that spot onto the table side by side, and they are to hover their hand over each one – your back still turned. At some point, you tell them to slam their hand on a certain one — it is their card!
A few points to consider:
– They have a free selection of card; no force or psy-forces.
– You never touch their card, not before, during, or after they pick it. You never alter, e.g. crimp, bend, etc., the card.
– You are not touching the deck when they return their card to it, nor when they shuffle or after they shuffle, or beyond that. You never need to touch it during the key parts of the effect.
This is exactly how it would look if genuine psychic power were being used. The 1st card they slam their hand on (and only the 1st card) could possibly not be their card, upon which you say “Yeah, I typically am off by at least one when I do this. Let me try again” and you will definitely nail it the second time. You won’t be wrong beyond that 1st card, ever. Or, you’ll nail it the very first time. The ‘mistake’ on the first time suggests that you must be relying on something other than already knowing the card’s location (and even that would be a miracle), which strengthens the notion that you are trying to ‘sense’ where their card is located.
With the right presentation, this comes off as one of the closest things to real psychic powers that the spectator could witness. This is Shadowsight, taking ‘find a card’ to a whole new level.