Seated at the table the performer invites a spectator to sit opposite him and assist in a straight-forward process. On the table in a row is a poker chip, a ball from a roulette wheel and a single die. Behind this row is a card case stood on its edge. All potent symbols of gambling in a casino.
The performer explains that competitive gambling, particularly poker, relies as much upon psychology and reading body language as it does luck. Clearly the ability to predict an individual's intentions and preferences would give you a big advantage at the gambling table.
The spectator selects any of the three items - and it is a free choice. The performer removes the card case, to reveal behind it what the spectator merely thought of!
It is super-simple, demonstrating yet again how resourceful Mr. Dobson is when taking a fresh look at a classic premise. Rarely will you wring this much impact from such a direct effect and simple but devilish means. In other words, all the hallmarks of 'The Dobson Approach'.
Quick, and to the point.