EFFECT

A spectator is asked to drop 3 dice into a glass of water, raise the glass over their head and count the total of the dice on the bottom. The spectator then sets the glass back down , the bartender dips his finger in the water, rubs his finger on his forehead and after a little concentrating , announces the total of the dice on the bottom to the spectators amazement.

METHOD

You need a glass of water and 3 dice. All you have to do is add up the total of the numbers on top of the dice and subtract this total from 21. This will give you the bottom total.