If you're borrowing a penny from a mark (someone in the crowd), then some sleight of hand skills will need to be mastered in order to swap out the real penny for the gimmicked one. THEN, the mark signs your gimmicked penny. This is the trouble for me, I'm no good at sleight and if the mark is wise, they WILL catch your sleight. Thus, I'd have to have more information b4 I bought the trick. I see on here where guys are having to practice for months on other tricks to learn them. Not for me. Gotta be self working with little practice.