There are many ways and methods that people have used to attempt to cheat slot machines in the quest for a dishonest buck. Many of the earlier methods involved trying to get free credits through having a coin on a string that could be whipped into the pay mechanism and removed before it got swallowed, or through modifying coins or tokens so they could be similar enough to earn credits, but different enough to get rejected by the slots game and end up back in the reject box.
When these methods were clamped down on, people turned their ideas as to how to increase payouts. When most slots return more than 90% of the money put into them in prizes, it just takes a small change to put the odds in the favour of the player slot. The main two devices were the “monkey wire” and the “light wand”.
Both were based on similar premises of tampering with the way the payouts were measured. They would be inserted into the slot via the payout system, and moved up into the coin dispenser. The monkey wire was a high risk strategy as if you were caught tampering with the machine your motives would be obvious.
The light wand was more subtle and sophisticated. It was an invention of Tommy Glenn Carmichael, one of the most notorious slots cheats. The wand relied on a light bulb, a battery and a cheap wire and was again sneaked deep into the machine. As light is the main way used to count the win payouts, using the bulb in the right place could confuse the system no end and increase the cash the machine would spit out. This again required the player to risk or face expulsion from the casino.