might be a prize token ...like if you break a balloon with a dart you then check to see what the metal disk on the nail it was attached to reads as your prize (the disk would face inwards )if you managed to hit a "big prize" like say the "watch" ( a pocket watch) thru slight of hand the barker would block your view with his body and drop the legit disc to the ground and then show you a "palmed" different disc instead with a "el crappo" prize instead