Most magicians have more than a passing knowledge of the workings of Las Vegas casinos. But George Joseph takes that insight several leaping bounds farther. Once a magician, he’s translated his knowledge of trickery and deception into an expertise in security and surveillance. He founded Worldwide Casino Consulting and is a leading expert in the field.

Joseph spoke to the Times Herald-Record about his work, including some of the preventive measures he’s helped implement to prevent cheating on casino floors. “Nothing on a table game is invisible,” he said, noting that digital cameras mean everything gets logged and monitored. But even as technology improves, there’s also no replacing that time-honored tradition of going with your gut. “In surveillance departments, they look for JLDR: Just Doesn’t Look Right,” he said.

So if you were thinking about plying your skills in magic to a less than honorable purpose at blackjack or roulette, here’s a tip: Don’t.

Penn Jillette & Teller are two of the most popular magicians in the world, and they’ve had a constant presence in Vegas for decades—so it’s about time that they had their own slot machine to fill the city’s many casinos. Fortune was with Penn during the unveiling, and actually hit the jackpot on his second spin on the machine, based on a report by KNTV.

According to the report, the duo was showing off the new, EVERI-manufactured machine at the Rio All-Suite Hotel and Casino, where the two have performed since 2001. Within a few minutes of sitting down to play, Penn won $286.20.

OK, so it wasn’t a jackpot, exactly, but it’s more than I’ve ever won at a casino, at any rate. The better trick is knowing when to walk away from the machine, which you can watch in action in the demo video below.