This is the effect Richard Osterlind has been carrying with him and using for over 40 years! It is one of the most baffling and mind-blowing pocket mental effects you will ever use. Here’s what happens:
A spectator puts a regulation casino die into a small wooden box and notes the number on top. The lid is closed and he verifies there is NO WAY to see the number. The performer takes the box and shakes it near his ear. He then names the number! This is repeated a second time with absolutely no clue as to the working. For the third time, the spectator puts a rubber band around the box and shakes the box himself! Still, the performer names the number!