by user24 » Mar 29th, '11, 09:23
Why not make actual lottery scratchcards (why make the cards stand out by being different?), and then you can do a mentalism routine where you take out a normal-looking lottery scratchcard and place it on the table. Talk about the way they're actually easier to guess than you'd think. Ask the spectator to doodle 3 objects on a pad, then scratch off the card and wow - the exact symbols on the card match!
As to the method... I'll leave that as an exercise for the reader (in other words I don't have a clue yet).