How do slot machines really work—pseudo-random or totally random?

The RNGs used in slots are actually PRNGs, or “pseudo-random” number generators. They’re mathematical algorithms that produce a sequence of numbers that mimic randomness, though not quite as perfectly as phenomena like radioactive decay or thermal noise do. But they’re good enough for players and regulators.

But imagine an infinitely long, random sequence of numbers. The RNG is always running, whether or not anyone is playing the machine, generating a new number every millisecond. Pressing the spin button (or pulling the lever) simply selects whichever number happens to be on tap at that moment, and translates it into a reel result.

Governments are fond of PRNGs because they’re predictable, traceable, and verifiable. Gamblers use them because the numbers that come out conform to the advertised probability distribution. You know you’re getting cheated – but at least it’s fair cheating.

In other words: yes, the video poker machines are not “truly” random, only pseudo, but that’s close enough for government work.

Las Vegas slot machines don’t actually rely on genuine randomness. Instead, they employ pseudorandom number generators (PRNGs) – computer algorithms that simulate randomness. The outcome of each spin depends entirely on the timing (or some other factor), so the casino can control how often the machine pays out. It’s not truly random from a mathematical standpoint, even if you can’t figure out what the pattern is. But people do win big! You can think of your odds here as more of a probability than a coin toss.