What is RNG?

An RNG (random number generator) is a crucial part of any slot game’s inner workings, underpinning the gameplay and ensuring that outcomes are determined fairly. As its name suggests, an RNG is a verified way of guaranteeing randomness. It’s essential that players believe and understand they are playing a game that is fair, not rigged.

What does an RNG do?

Slots are games of chance, but for this to truly work, online video slots need to be based on an RNG, which essentially determines the outcome of every spin. 

Whether it’s the position of an online slot game’s reels, an animated roulette wheel, the shuffle of digital cards, or the roll of a virtual dice, the outcome is determined by an RNG.

Why were RNGs introduced?

In old-fashioned mechanical slots, outcomes were literally determined by the physical reels and gears of the machine. However, these were limited in the number of outcomes and bonuses that could be included. 

As technology advanced, manufacturers began using electronic systems to simulate randomness, which led to the development and adoption of RNGs as we now know them.

The development of RNGs has paved the way for modern slots, allowing for things like bonus rounds, progressive jackpots, and other mechanics that require calculated randomness.

How do RNGs work?

Essentially, an RNG is an algorithm that produces numbers at random, so that the outcomes of a game are entirely unpredictable – which is key to player perception of fairness.

They produce strings of numbers constantly, thousands every second, even when you’re not playing. When a slot is spun, the RNG randomly selects a number, which corresponds to a particular position on the reels. 

Pseudo RNGs

Most slots use a ‘pseudo RNG’, which generates numbers based on mathematical formulae and a seed value. Also widely used outside gaming, a pseudo-random number generator (PRNG), is an algorithm that generates a sequence of numbers whose properties approximate the properties of sequences of random numbers. It's also known as a DRBG (deterministic random bit generator).

True RNGs

A true RNG (TRNG), on the other hand, uses physical phenomena such as atmospheric noise to determine outcomes and are more awkward to use. They aren't needed for slots, however.

The difference between pseudo and true RNGs is explained here.

Why are RNGs important?

RNGs ensure fairness and unpredictability, so that every spin stands an equal chance of having any particular outcome. 

Also, the use of RNGs is a condition of regulatory compliance. Regulators like the UK Gambling Commission (UKGC) will only issue licenses to casino operators and game developers who have demonstrated that the RNGs underpinning their games are 100% fair.

Proving fairness

This process of proving fairness involves testing and auditing. Audits are carried out by the UKGC directly, as well as by independent organisations like eCOGRA, Gaming Laboratories International, and iTech Labs. Tests are run to confirm randomness, and certificates are issued.

RNGs are essential to players’ peace of mind. Before the use of verified RNGs, it was possible for games to be ‘fixed’, and the modern system makes this a virtual impossibility. 

RNG myths

There’s a lot of misinformation surrounding the mechanics and workings of slot games. Here are a few important truths to keep in mind:

• You can’t ‘beat’ an RNG. There is no way to accurately predict the outcome of an RNG.
• A slot is never ‘due’ or ‘ready’ to pay out. Every spin has the same chance of winning as the one before it, contrary to gambler’s fallacy.
• There aren’t degrees of randomness. RNGs are independently tested, and even casinos can’t manipulate the outcome of games.
• RNGs aren’t time-sensitive. Some have suggested that slots pay out at certain times, to keep players playing. This isn’t the case; random is random.
• Land-based slots aren’t rigged. Whether physical or digital, modern slot games use the same fundamental rules to ensure fairness. Outcome (and house edge) is determined by the mathematical model of a game.

Summary

RNGs are a vital part of making the online casino experience safe and fair for players. These verifiable algorithms are responsible for determining the outcomes of each and every spin of the reels.