Field guide

EMP Jammer / Magnetic Interference

How it works

A device that emits an electromagnetic pulse to disrupt a slot machine’s internal electronics, potentially causing malfunction, credit miscounting, or jackpot triggering. Cheaters conceal a high-voltage coil or spark gap device near the machine. The EMP interferes with the machine’s microprocessor, causing errors in the random number generator or credit system. Some versions use strong magnets to influence older mechanical reels.

On the record

EMP jammers have been sold on criminal forums and used in European and Asian casinos. Chinese authorities have arrested groups using high-powered jammers against slot machines and arcade games.

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.