Without the magician seeing, the spectator can freely select any number on the die and place it inside a small black box with the chosen number facing up  -  and closes the lid. That box is placed inside another larger one and again capped with a lid.  Yet the magician always knows which number was selected by the audience - even though the choice was made out of sight.  This can be repeated with a different number - and the performer is always right.

This can be demonstrated as a "mind reading" trick or the magician can claim to have "X-ray vision"...either way, it's simply amazing and simple to do.
Includes the famous Trap Door Magic® easy-to-learn step-by-step video tutorial.