The ESP Deck is a set of 25 symbol cards. Originally designed by Dr. Joseph Rhine in 1927 to test extra Sensory Perception at Duke University, each set has five symbols (Circle, Cross, Waves, Square and Star) repeated five times. Magicians have used this decks for decades to perform demonstrations of mental telepathy, clairvoyance pre-cognition and other such demonstration of ESP. It is very easy to adapt many popular card tricks for use with the ESP cards to give them a pseudo scientific or mental favor.