How Cheaters Used to Prosper: 5 Slot Machine Tricks and Scams

For as long as there have been slot machines, there have been scammers trying to cheat the casinos. Thanks to modern tech and top-notch security systems, it’s now almost impossible for cheaters to prosper. But that hasn’t always been the case, according to the casino experts from

Check out 5 tricks and scams slot machine fraudsters once used to fatten their pockets. Just remember not to attempt any yourself because (a) they’re unlikely to work and (b) you’ll get yourself arrested.

1.  The Yo-Yo Coin

There’s nothing high-tech about the yo-yo coin trick.

Scammers would drill a hole into a coin and attach it to a piece of string. The money could then be dropped into a slot to trigger the coin-counting mechanism before being yanked back out. This would allow the cheater to play without losing any cash.

The hack used to be very popular in Las Vegas. Even if it wasn’t totally illegal, it’s pointless trying to pull the yo-yo coin trick off today though. Most slot machines no longer accept coins, and instead operate with a ticket-in-ticket-out system.

2.  The Slug

Back when slot machines accepted coins, casinos also had to watch out for slugs.

We’re not talking about the garden pests that chew holes in your vegetables. We’re talking about fake coins that can trick slot machines into thinking they’re the real deal.

In the 1980s, a hardware manufacturer produced a line of washers that happened to be the same shape and weight as an American coin. It wasn’t long before cheaters were dropping them into slot machines to spin the reels illegally.

3.  The Monkey Paw

You can’t talk about slot machine cheats without mentioning Tommy Glenn Carmichael. One of history’s most notorious cheaters, Carmichael was responsible for several common casino hacks, including the Monkey Paw.  

The Monkey Paw was a foot-long device with a clawed end. It could be forced into a slot machine’s payout mechanism to trigger a win without any wagering.

Luckily, after a lengthy prison stretch, Carmichael saw the error of his ways. He teamed up with the Nevada Gaming Commission to help casinos protect themselves against Monkey Paws and other inventions used to cheat the slots.

4.  The Magnet

Before slot machines went digital, it was possible to force a winning combination onto the reels using nothing more than a magnet.

Tricksters would hover a magnet over the reels to make the symbols float. Once they had created a winning combination, they would remove the magnet to make the machine pay out.

Magnets no longer pose a threat to casinos for two reasons. Firstly, modern slot machines are protected against magnets. And secondly, the symbols you see on today’s reels are purely superficial, and do not determine the outcome of spins.

Instead, whether you win or lose is determined by an RNG (or pseudo random number generator). And cracking the code of the RNG is seriously hard – as a group of Russian criminals found out in 2017.

5.  The Russian Hack

Just over a decade ago, gambling was made illegal almost everywhere in Russia. This led to a lot of slot manufacturers having to sell their machines.

Many wound up in the hands of fraudsters, who pulled the machines apart to try and figure out the RNG’s complicated algorithm.

In 2017, some of these fraudsters headed for the casinos of the USA. They used their smartphones to record a dozen or so spins on the old slot machines, then sent the footage back to their teams in Russia. Their teams calculated when a big win would strike and told them when to spin.

You may be impressed by how clever this scam sounds. Unfortunately for the Russian hackers, it wasn’t clever enough to fool today’s casino bosses. Four were arrested for conspiracy to commit fraud in casinos in Missouri and Illinois.