Part III: Slot Machine Cheating · Physical Cheating Methods

SCAM #15: The Tongue

How it works

Tommy Carmichael’s final major invention, developed as the industry transitioned to TITO (ticket-in/ticket-out) systems that eliminated coin hoppers. The tongue exploited a flaw in how machines counted inserted coins using three light sensors. When a coin dropped in, it passed by three light sensors that tracked how many coins were being inserted. Carmichael discovered that by inserting the tongue device into the coin slot and moving it back and forth in front of the middle light sensor, he could trick the machine into thinking hundreds of coins were passing through. The device could rack up approximately 35 credits per second on a quarter machine. One person could load credits, leave, and an accomplice could later collect them, making detection extremely difficult.

Where it appears

TITO-era slot machines that still accepted coins for credit, using multi-sensor coin counting systems.

On the record

The tongue was the device Carmichael was developing when he was arrested in Atlantic City in 1999. FBI wiretaps recorded Carmichael and his crew discussing the device. He dreamed of making $1 million in six months and retiring. The planned rate was approximately $2,000 per second on $5 slots. Carmichael was sentenced to 11 months in prison in 2001 and added to Nevada’s Black Book.

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.