There’s usually a sign either on the slot machines themselves or prominently posted in each casino that all machine malfunctions void play. Here in Nevada there have been several court cases where a reel machine malfunctioned and stopped on what appeared to be a winning combination, but wasn’t. The gamblers always lost because of that warning.

However, it’s arguable that this was a malfunction. It wasn’t set up properly, nor was it tested properly to find that the wrong chip was in it, but it didn’t malfunction, technically.

I work for a slot machine company and I know that in most, if not all, jurisdictions (can’t say about Indiana — never been there) each machine has to be coin tested to ensure it’s set up right and it’s par (payback percentage) and other information recorded by the local, state or tribal gaming commission before it can be put on the floor. If this wasn’t done, the casino is liable for a huge fine up to being shut down.

As for going after those who took advantage of this, I think a court will have to determine if it was a malfunction or the casino’s fault. If you figure out that one machine pays back more than another and continue playing it, you aren’t breaking any laws. Is this that much different? It’s just the ‘why’. On the other hand, taking ‘extra’ money from an ATM that spits out too much is illegal, I think, so this may be a related situation. Depends on the laws of the jurisdiction. On the third hand, these people who didn’t report it, kept playing and kept the winnings are amazingly stupid. With every square inch of a casino watched from multiple angles by cameras recording every move, there’s no way to escape them finding out who you are when they catch the problem. You at least knew that, didn’t you?

Is Winning on Faulty Slot Machine a Crime?

Prosecutors are considering criminal charges against casino gamblers who won big on a slot machine that had been installed with faulty software.

The machine at Caesars Indiana credited gamblers $10 for each dollar they inserted because the software wasn’t designed for U.S. currency, state police said. More than two dozen people played the machine before one gambler alerted Caesars employees.

A decision on whether to bring criminal charges could come in a couple of weeks, said John Colin, chief deputy prosecutor for Harrison County. He said “criminal intent” may be involved when people play a machine they know is faulty.

When a slot machine jams and gamblers lose money, they don’t get it back, she said.

“It doesn’t work in the reverse,” Ford said. “They need to forget it and move on.”