Part III: Slot Machine Cheating · Physical Cheating Methods

SCAM #21: Zip Strip (Bill Stringing)

How it works

The paper equivalent of the coin yo-yo. A cheat attaches a string (sometimes dental floss) to a high-denomination bill, often coated with Zinc Stearate (“zinc soap” or magician’s fanning powder) to make it slippery. The bill is inserted into the bill validator, credits are registered, and then the bill is pulled back out through the validator using the string. The ratchet mechanism in the validator is supposed to prevent backward movement, so cheats would attach a paperclip to the bill to try to hook and hold down the ratchet paw, allowing extraction.

Where it appears

Early bill validators with inadequate ratchet/paw mechanisms.

On the record

George Joseph noted that the discovery of very few paperclips in bill validator cans suggested this method “was not very good” and rarely succeeded. However, the attempt alone is evidence of intent to cheat.

Published as a detection reference for surveillance, compliance and gaming-operations professionals. Thresholds and tuning are set by the property. Nothing here is instruction — the method is described so it can be recognised.