big_z said:there were two acts that i could swear penn and teller guessed right but the magician(s) lied anyway for the trip to vegas. one was the two guys predicting profile cards where they cut out a penn silhouette at the end. the other was some dude returning to the show but i cant remember the trick.
There's an independent judge who has been shown the trick - which the participants must not deviate more then cosmetically from - and the workings. The participants cannot lie. They *can* be extremely careful with their wording, mind you.