This way of cheating slots is not technically a fraud or scam. However, slots are programmed by people, who can make mistakes. A programming error can lead to a software glitch, which can later (consciously or unconsciously) be explored by players.
There are many documented instances of software glitches that have resulted in huge wins:
- In 2015, a 90-year-old woman from Illinois won $41 million while playing a Miss Kitty slot machine. The casino rejected to pay her out.
- A man in Austria won a €43 million jackpot. However, the casino insisted that he only hit 4 of the 5 symbols needed to trigger the jackpot. Therefore, his win wasn’t paid out and he was offered 100 bucks and a free meal instead.
- A woman in New York managed to hit an amazing $42.9 million jackpot. The machine had a maximum payout of $6,500 and the huge win was just a glitch. The casino insisted that she was only entitled to the $2.25 from her spin.
So the issue is that huge wins that happen due to software glitches are virtually never paid out. And what's even worse, some casinos may use that excuse to not pay out real wins, blaming a glitch.
However, a software glitch doesn’t always have to result in hitting a jackpot. It might instead provide a player with a stream of smaller wins, or misinterpret the money inserted into the machine in a way that favors the player. Instances of this kind can stay under the radar, and can be exploited by crafty players.
You have to be extremely lucky to find this type of bug though. And even if you managed to do it, you can never be sure that you will actually get to see the money.