*** Welcome to piglix ***

Forcing (magic)


In stage magic, a force is a method of controlling a choice made by a spectator during a trick. Some forces are performed physically using sleight of hand, such as a trick where a spectator appears to selects a random card from a deck but is instead handed a known card by the magician. Other forces use equivocation (or "the magician's choice") to create the illusion of a free decision in a situation where all choices lead to the same outcome.


...
Wikipedia

...