In the simplest format, a trader is given a prize or cash amount of medium value (on the order of a few hundred dollars), and the host offers them the opportunity to trade for an unknown prize. This latter item may be concealed on the stage behind one of three curtains, within a large "box" onstage (large panels painted to look like a box), inside a smaller box carried on a tray, or occasionally in other formats. On occasion, the initial prize may itself be hidden behind a curtain, or in a box or some other container.