Fwiw, I operated these games when they were new. You must use the cards with the plain cardboard backing. The cards that are slick on both side will not work, the rubber wheels will not grip them. Also, very important to insert the cards with the rough side facing the wheels. We eventually gave up and took the units off the machines after about a year. If I remember right, the card companies all went to the nicer glossy cards right after the machine came out, making it hard to vend current year cards.