This is an mechanical version of the classic "Find The Lady" effect. originally performed with years of practice using sleights, as a betting game. This version uses Giant cards (18" x 12"), thereby implying to the audience that no sleights are involved. It also makes the item suitable for stage or platform use.
Effect: Performer shows three cards, say two black Kings and one red Queen. Cards are turned back towards audience, and mixed, and a spectator invited to find the Queen. No matter which card he selects, he always gets one of the black Kings, and one of the other two cards proves to be the Queen.