How does an RNG work?

Whether you play the latest console games or you’re a regular at Paddy Power, it’s extremely likely you’ve come into contact with random number generating (RNG) software.

Its use in games is so ubiquitous that it’s extremely unlikely you’ve played something that doesn’t use it at all. But despite how often it’s used, the technology itself is only dimly understood by a number of players. Getting your head around RNGs can help you understand the games you’re playing and you may be surprised by how many different applications they have in your day to day life.

Essentially, a random number generator is any method used to generate a number that is, for all intents and purposes, unpredictable or at least could not be predicted any better than by random chance.

One of the most interesting things about this is that from one perspective, there is no such thing as a true random number generator.

A large amount of the RNG software available today is better described as a pseudo-random number generator. This software requires a seed number to work from and then this will generate the random numbers as the start point, essentially you enter a number and the generator works from there.

The removal of the randomness element is that the number selected will have an effect on what the results you receive will be and the mathematical formula (such as the linear congruential method) will be at least somewhat deterministic meaning it can be repeated. While this is beneficial if you need to repeat the results, for instance if you are seeking to simulate or model as you can try again while testing variables, it is a detrimental feature if you are, say, using it to simulate a dice roll.

Fortunately, there is also the option to use a true random number generator which, rather than use a selected seed number, uses an observable phenomenon that can be generated at random. The most common example is the point of time a radioactive source decays as it is something that we are unable to predict but is very easy for a computer to observe and use as a randomized starting point. Other elements that can be used are background atmospheric noise and one former generator used the movements of lava lamps as a starting point.

With how random these phenomena are, it may seem odd to say that true randomness isn’t achievable but there are elements that make it debatable. One is systematic biases in how the natural event is recorded, resulting in recordings that are not uniformly random, and the other is that the observable events may not truly be random. Just because it is currently beyond human understanding to predict when a radioactive isotope will decay, does not mean that the event itself is not predictable and could mean that the events are not truly random (even if we are not able to predict them).

How often do you find yourself using an RNG? Do you think they’re really random? Let us know in the comments below!