There’s a simpler variation I learned as a kid.
Start with a limited pool of items, say five or six, and arrange them in a line on a table or tray. If you really want to make it seem hard, have the marks choose the items themselves on the spot.
The patter for this bit went something like “I’m going to form a psychic bond with the items, so that they can speak to me and tell me when they have been chosen.”, in an effort to explain why I couldn’t guess just any old item at will.
Once the psychic is turned around/blindfolded/out of the room, the helper then fills in the psychic with a simple alphabetic code where the first letter of the comment or question is the position from left to right; Say the third item is chosen, the helper would hold it up and ask “Can you see what I’m holding?” or “Crap, I don’t know how you keep getting these right.”
After a while, someone will inevitably try to cheat. For items not on the tray, or no item chosen, we’d use the name of the person trying to cheat. “Sarah has made her choice! What item am I holding?”, to which the response ran “Of course not. None of the items are speaking to me, so Sarah didn’t choose any of them.”
For multiple items we used the psychics name as a tell. If the first and third items were chosen, the patter would run something like “Frank? Are you ready?” / “Yes” / “Can you tell me what I’m holding?” / “I see the [third item], but there’s more than one speaking to me. There are two of them, [third item] and [first item]!”
