
In 1992, a casino employee, William John Brennan, walked out of the Stardust casino with chips and cash amounting to half a million dollars in a sack and vanished. Despite the presence of surveillance cameras throughout the casino, there was absolutely no footage of his exit. It's been more than three decades, and he still hasn't been seen again.

In the early '90s, Ron Harris, a software developer, was appointed by the Nevada Gaming Control Board to code an anti-cheat program. But alongside the anti-cheat program, he secretly designed a hidden switch that triggered a jackpot when coins are put in the slot machines in a certain way. He stole from 30 slot machines together with his friends. He was later caught and sentenced for seven years.

Between 1970 and 1990, the MIT Blackjack Team devised scientific card-counting methods and used them against gambling clubs to steal millions. The team was comprised of undergraduates and graduates from reputable universities such as MIT, Harvard, and other institutions. The pioneer of the group, Bill Kaplan, supposedly made about $10 million throughout the years. Casinos discovered the plot, and individuals from the group were banished from betting. This scandal inspired the movie '21'.

After moving to Las Vegas, Richard Marcus became homeless but later found a job as a baccarat and blackjack dealer. As he learned the intricate details of the games, he discovered approaches to defraud the system. One of his best tricks was "past posting," or late wagering, in which he'd bet low amounts, hold back to check whether he'd won, and then secretly switched the low-denomination chips with higher-value ones to win big. He managed to swindle more than $5 million. He was finally caught by law enforcement but was never imprisoned.

For more than two decades, an individual named Tommy Glenn had been known to steal millions of dollars from gambling clubs by using devices that manipulated the slot machines. One of his creations was known as the'monkey paw.' It was a cable that he would insert into the payout space of the slot machine. The cable would tamper with the micro-switch, which would then release huge amounts of money.