by John Racherbaumer
The 21 Card Trick is one of the single best known card tricks by non-magicians. Often when a magician is approached by a lay person who wants to show him a card trick -- it is the classic 21 Card Trick, where a thought-of-card is discovered by a series of deals where the magician or spectator deal three packets of seven cards and eventually reveal the thought-of selection. Within the underground of card magic there have been dozens of variations created where the procedure looks the same to a lay person but the results are impossible. You can literally blow the mind of a spectator by doing the trick he just showed you back to him and fooling him completely. But that is not all. The devious mathematical method has many other applications and they too are discussed, taught and presented here.