Casino Random Number Generators Explained: Why Online Casino Games Aren’t Rigged

How do you know the online casino games you’re playing are fair? The answer is casino random number generator (RNG) technology. Despite being the fairest way to create random results, some people still doubt the integrity of RNGs.

I’m here to explain how random number generators work. In doing so, I’ll prove that online casino games aren’t rigged and show you why it’s important to use licensed gambling sites.

So, if you’re a little unsure about online casino gaming and want to know why it’s completely legit, here’s the lowdown on RNGs.

What is RNG?

A casino random number generator, also known as an RNG, determines the outcome of games. Specifically, RNGs are algorithms that ensure the result of every game you play is fair within expected parameters.

The “expected parameters” part of my last sentence is important for reasons I’ll explain in a moment. For now, just hold onto the idea that a random number generator ensures casino games are unpredictable and fair.

How Do Casino Random Number Generators Work?

The name alone tells you what a casino random number generator does. However, for the purposes of clarity, let’s get technical for a moment.

An RNG generates thousands of numbers every second. A casino random number generator never stops, so numbers are being produced constantly.

These numbers correspond to different outcomes in whatever casino game you’re playing. The number produced at the exact time you place a bet determines the outcome.

That’s how you get random results every time you play casino games at licensed gaming sites. An algorithm is constantly creating sequences of numbers, and one is chosen at random based on a trigger point. The trigger point is the moment you place a bet.

Types of Random Number Generator

I said earlier that random number generator casino technology is “fair within expected parameters.” That’s important because all casino games have an expected value. This is known as the house edge.

In simple terms, the house (aka the casino) has a slight advantage in all its games. The casino house edge, in combination with your average bet size, determines your expected long-term win rate.

Software developers have to take these factors into account when they’re creating casino games. That’s why an online casino’s random number generator has to include a rule for the game’s house edge.

This is why I said games are fair within expected parameters rather than truly random. The results are always random, but they’re random within a framework governed by the game’s expected long-term payout potential.  

In line with this, there are two types of RNGs: true random number generators (TRNGs) and pseudo-random number generators (PRNGs).

True Random Number Generators (TRNGs)

TRNGs produce random numbers based on atmospheric noise. What is atmospheric noise? Atmospheric noise refers to random electrical signals generated by natural phenomena like lightning storms, solar activity, or other environmental factors. Someone with the requisite skills can record these noises and use the audio files to code a random number generator.

The atmospheric noise not only ensures that the results are genuinely random but also that a seed value isn’t required. In essence, the lack of seed values is the fundamental difference between TRNGs and PRNGs, as will become clear in a moment.

Pseudo-Random Number Generators (PRNGs)

PRNGs produce random numbers based on seed values. Seed values are selected at random and initiate a sequence of numbers. These sequences of numbers are predetermined according to specific rules.

For casino random number generators, the rules reflect a game’s betting conditions and the house edge. This goes back to what I said earlier about numbers being generated at random within a framework of expected values.

The “rules” create sequences of numbers that fall within predetermined parameters. The system remains random and fair because seed values are chosen at random.

Seeds Don’t Make Games Predictable

The process isn’t truly random because seed values are programmed into the software based on specific rules. However, even though the seed values are known, you can’t predict which one is going to be used in any given instance.

Furthermore, it’s impossible to know which number within the current sequence you’re going to hit. Therefore, the process is fair and random. The way I think of random number generators for online casino games is that they operate within a framework.  

An analogy I like to use is a bingo drum made of see-through plastic. The transparent drum is the framework because it controls how the balls are mixed up, but a ball is chosen at random. Therefore, even though you can see the balls, you can’t predict which one is going to be selected.

It’s the same with seed values. You might know the seed values for an RNG, but it doesn’t mean you can predict the outcome.

Why Are RNGs Important in Online Casino Gaming?

Random number generator casino technology makes games fair. When you play games in a land-based casino, you can see cards being shuffled, roulette wheels spinning, and other random processes taking place in real time.

You don’t have that luxury when you’re playing online casino games. That’s why we rely on RNGs to ensure the results are unpredictable and fair within defined parameters.

Of course, as smart players, we know to be skeptical, which is why legit online casino operators have their RNGs certified by independent testing agencies.

What are RNG Certificates?

Every random number generator online casino operators use is audited by a third party. These companies use Monte Carlo simulations to test an RNG’s results. Monte Carlo simulations run thousands of trials to determine whether the results fall in line with mathematical expectations.

So, when a testing agency audits the RNG for a slot game, it spins the reels thousands of times to see if the average win rate falls in line with the game’s pre-determined RTP (return to player value).

Once a game passes these tests, it gets certified as fair, but that’s not the end. Game developers and operators must provide open access to their source codes. This allows testing agencies to monitor games continually.  

Some of the testing agencies used by the top online casinos are:

• Gaming Labs International (GLI)

• iTech Labs

• eCOGRA

Common Misconceptions About RNGs

Some people wrongly assume that online casino games are rigged. Everything I’ve explained in this guide to casino RNG technology should tell you why that’s not the case. But just so you’re absolutely clear, online casino RNGs can’t be tampered with.

An operator could, in theory, change an RNG's source code and make it harder for you to win. However, as I’ve said, testing agencies continually monitor online casinos and other gambling sites.

What’s more, there are plenty of smart people out there who understand the nuances of casino random number generators. They’d quickly spot a dodgy algorithm and report it to whichever regulator licensed the casino in question.

In short, all online casino games are fair because random number generators are audited by reputable companies. So, as long as you stick to licensed online gaming sites, you can be confident that their games are 100% fair.