21 Card Trick
Twenty-One Card Trick is a classic plot in card magic where three piles of seven cards are dealt on the table. The spectator is asked to remember one of the 21 cards. The piles are gathered and re-dealt then the spectator is asked to only identify which pile the card is in. This is repeated one more time and the magician is then able to identify the selected card.
The first card trick learn by many beginners.
This is an old mathematical effect based on principles developed by Joseph-Diez Gergonne (a French mathematician) called the Gergonne Pile Principle.
- 21 Card Trick Streamlined by Ed Marlo in The Cardician (1953)
- Nouveau 21 Card Trick can be found in Marlo Without Tears (1983)
- Jim Swain's handling in 21st Century Card Magic (1999)
- The World's Most Obscene 21 Card Trick in The Little Egypt Book of Numbers by Steve Bryant (2004)
- Tom Craven's 27-Card Trick, in Best of Friends, Vol. 3, written by Harry Lorayne (2007)
- Jon Racherbaumer's ebook, The 21-Card Trick: Rigged, Reconsidered, and Retro-fitted (2007)