Meet history's most famous slots scammers

Over the years, many people have tried to scam the online gambling for real money slot machines. Scamming slot machines was more popular before the introduction of the automatic hopper and the random number generator but even then, it wasn’t easy. Today, with modern technology, it’s harder than ever. However, the challenge doesn’t keep people from trying.

It’s more common to hear about attempted scams at a brick-and-mortar casino than at an online casino because the land-based casino machines still involve an element of physicality where, some people think, it’s easier to cheat the system than at a technology-based site. 

Slot machine cheats have included techniques such as using fake coins or slugs, trying to adjust the spins using magnetic force, tying a string to the coin that was placed in the machine and using programmed chips.

Remember – cheating the slot machines is a felony and, when you’re caught, you could serve jail time for your troubles. Don’t bother.  But it’s still interesting to read about some of the attempts of the past 


Yo-yoing is the granddaddy of all slot machine scam techniques. It’s the basis for most other scam attempts, even though it’s simplistic and primitive. Yo-yoing a slot machine basically involves tying a string around a coin and dropping the coins into the machine.

As soon as the machine registers the credit, the person holding the string yanks out the coin and plays the machine, collecting whatever wins are delivered. The coin can, theoretically, be used again and again. 

In today’s non-coin-operated slot machines, the yo-yo technique doesn’t work but in the early decades of slot machines, it was relatively successful. 

Fake Coins

A variation on the yo-yo technique is the fake coin scam in which fake coins that are sufficiently similar to real coins are used. These sorts of coins were actually manufactured commercially (illegally, of course) by Louis “The Coin” Colavecchio who pressed counterfeit slot machine coins out of metal. Colavecchio’s coins succeeded in tricking machines along the East Coast for years as recently as the ‘90s.

Coin Shaving

Coin shaving is similar to yo-yoing which came into being when casinos put optic verification sensors into their slot machines. Instead of preventing the scams, the technology gave rise to a new way to cheat at slots.

Scammers found a way to turn the sensor on itself. They discovered that, if a coin was slightly shaved around the edge, it would be registered as a normal coin by the optic sensor. However, the machine would toss the coin out the bottom because of a slight weight discrepancy when the coin reached the machine’s comparator mechanism. This allowed scammers to pull the coin out without using a string.

Monkey’s Paw

Tommy Glenn Carmichael discovered that slot machines contained a switch which was designed to release the coin hopper. He built a contraption out of a guitar or piano string that was attached to a bent metal rod. The device would be jammed into the machine through an air vent.  Carmichael then used his device to locate the switch and flick the switch. This would trigger the release mechanism and the coins would come pouring out.


Dennis Nikrash was named as the “mastermind of the biggest slot-cheating schemes in Nevada history”. 

He used a key to beat the slot machine system in the 1970s and early ‘80s. Nikrasch and his gang would distract the slot machine mechanics and use the time to make imprints of the slot machine’s cabinet key.

They would return to the machine at a later time and use the key to open the machine and rig it in such a way that the reels would be set on a winning jackpot combination.

Nikrasch was caught and served time in prison but after he was released he returned to Vegas and devised more sophisticated methods to cheat the machines. It’s said that he netted about $16 million from his slot machine scams, was sentenced to prison twice and was banned from casinos altogether in 2004.

Computer Hacking

The most recent, successful, hacking operation was conducted in US casinos in 2014 by Russian operatives who succeeded in identifying the components that go into creating a pseudorandom number generator. PRNGs are programs that produce undetermined results by design. The scammers succeeded in using that knowledge to predict the PRNG’s output. Once again, this can only be accomplished with a land-based slot machine as opposed to an online casino video slot.

The process of reverse engineering gave the hackers the secret algorithms that a slot machine uses to create pseudorandom results. They then analyzed the gameplay, discerned the machine’s pattern and used that knowledge to create timed spins that result in higher payouts than a machine normally awards. 

This scam is, evidently, still operating, though now at an even more technologically-advanced level. Game developers can thwart this scam using encryption that protects the PRNG’s mathematical secrets but that doesn’t protect the older, compromised machines that still populate many casinos.