Set includes 25 Rider backed ESP playing cards. 5 of each symbol (star, square, circle, cross, wavy lines). Set of 5 allows for layering of most mentalism routines to create unbelievable predictions, "proving" Extra Sensory Perception (ESP). ESP cards are a staple of mentalists -- but perfect for kids shows and everyday use. Printed by USPCC for top quality and using the familiar Rider Back design so you can seamlessly predict an ESP symbol from your regular BicycleÂ? deck. Originally developed and used at Duke University for the testing of ESP, these easy-to-remember symbols, along with a commonly-used but secret numbering system, will allow you to create miracles: Circle = 1 line Cross = 2 lines Wavy Lines = 2 lines Square = 4 lines Instructions not