How Does RNG Work in Online Casinos?

Online casino games use random number generators (RNG) to create certifiable outcomes during each round of gameplay. An RNG is essentially an algorithm that is constantly generating sequences of numbers. Each sequence directly translates to an outcome in the game. For example, slot games will have any given outcome of symbols mapped out within the algorithm. The moment you press the spin button, the algorithm stops at the number in the sequence and then displays the outcome tied to it.

Which games use RNG?

Any given random number generator in casinos is widely used across a selection of games. It is easy to spot which ones use RNG, though, as they exclude any table game with an actual croupier. Online slots and virtual games all use RNGs to determine the outcome of any spin or game round. Land-based casinos also use them in most of their automated games. Any slot or virtual casino game that you play online will be operated by an RNG algorithm. This includes games like virtual roulette, virtual blackjack, and video poker.

Why is RNG important?

Online casino RNG is important as it ensures fairness in each game round. As the algorithms are created and tested by 3rd parties, there is no way for the game providers or casinos themselves to influence them. The outcomes tied to each number sequence are hard-coded into the algorithm. Essentially, this means that the games can’t be purposefully rigged or set up in a way to secretly change over the course of a gameplay session. 

Casino RNG FAQ

Are RNGs tested?

Online casinos are regularly audited by third-party testing organisations. Auditors like TST or GLI are independent organisations that do regular checks on the RNGs used by online casino games. Sites can then be certified, which is a stamp showcasing that their games are verifiably fair. That is how online casinos use random numbers in a trustworthy way.

How do I know if a game is rigged?

The best way to avoid rigged games is by playing at a licensed online casino. Licensed sites are regularly audited and required to prove that their site is fair and safe. Failure to adhere to the rules set out by the licensor can result in heavy fines or their licence being revoked, making them illegal to operate. The MGA and UKGC are two examples of widely used and highly respected licensing bodies.

Do previous rounds affect future outcomes?

Random number generators ensure that each round is independent from the last. Any win or loss streak is, therefore, purely coincidental. Game providers and casinos have no way of affecting the RNG, and each round is determined the moment you press the button.

Does RNG affect payouts?

RNG does affect the return to player percentage (RTP) due to the different combinations being set in place within the algorithm. The return to player (RTP) percentage reflects how much return a player can expect over an extended period of gameplay. For slot games, this tends to hover around 96%. As the percentage can vary, this does mean that the RNG algorithm has been integrated with the game in mind. The way the different game symbol combinations have been mapped out within the RNG algorithm can change the probability that a jackpot round will hit, for example.