[gyom]

That's kind of a cool approach. As long as you can "salvage" the trick, then nobody needs to know about the failed portion.

One of my friends had a card trick that involved me selecting a card. Before starting the trick, he jokingly picked a card at random from the deck, and asked me if that was my card. He had 1/52 chances of being right, but it would have been an insane trick if it had worked.

He guessed wrong (naturally), shrugged and went on with the actual trick as though the first attempt was just a joke, to be forgotten because an actual trick was about to take place.

[glomph]

He may also have been practising a risky method of forcing a card on you. It is standard advice to do this often as it is the only real way of getting good at it.