Dice Switching Dixie Cup Set. One gaffed and two fair cups. A secret panel, concealed in the gaffed cup, allowed the operator to switch dice inside a seemingly empty receptacle, matching those passed to other players in the gamer that were entirely ordinary. A thumb-operated lever on the exterior of the cup switches one set of dice for the other inside. With two sets of dice of different colors for demonstration. A unique prototype and seemingly innocent version of the classic ?Butterfly? dice switching cups.