How Does RNG Work in Online Casinos?

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Back in time when mechanical slot machines were the thing, players believed they could influence the payout by “feeding” the machine with coins. On the other hand, rumor h

as it that casinos used to take control of the number of coins in machines to prevent frequent cashouts. However, even if this has been possible before, it is no longer the case.

Once we stepped into the age of technological development and online casinos, these theories faded to dust due to the invention called the Random Number Generator. The RNG is a software meant to secure fairness and randomness of casino games, and you can read about in the text below.

What Is RNG and How Does it Work?

The Random Number Generator is a program code that uses the MD5 algorithm built into a casino’s software. Its job is to generate random symbols or numbers used in a variety of casino games and completely exclude the possibility of tampering with their outcome.

The goal is to avoid the repetition of any particular pattern and ensure different results every time, which is achieved by mathematical equations and formulas that make up the RNG’s algorithm. Finally, the randomness of games in online casinos should resemble the one in land-based establishments.

Let’s say that you are in a land-based casino playing poker. Before every game, the dealer will shuffle the cards, thus securing the randomness of the game. After that, the cards you will get will be the first top cards from the deck that are absolutely unknown to anyone.

However, in online casinos, there is no dealer to shuffle the deck of cards, and so the casino software has to do it instead. This is when RNG comes in and provides random numbers that consequently determine the card you will get.

Types of RNG

There are two types of Random Number Generators — Hardware RNG and Pseudorandom RNG. While the aim is the same for both, they do differ in some ways.

Hardware Random Number Generator

Hardware Random Number Generator is a sort of an external gadget that casinos connect to their server through a USB port. It represents a small board or a chip packed into a device that produces a random series of numbers triggered by the unstable atmospheric phenomena or physical processes.

This type of RNG is also called a True Random Number Generator and has been used in land-based casinos. Once connected, the device uses compound values as a starting point for developing a result of, for example, a roulette game. Contrary to the belief of many, the Hardware RNG cannot be rigged, as it is placed inside the machine and properly secured.

Pseudorandom Number Generator

Pseudorandom Number Generator is a tool used to secure randomness of games in online casinos. As opposed to Hardware RNG, Pseudorandom Number Generation is a software that features a mathematical algorithm instead of a physical device. This program code alone is in charge of generating random numbers and determining the outcome of the games.

PRNG is constantly producing new random number sequences. Its starting point is the number with millions of digits after the decimal. Then, from this starting number, numerous mathematical operations follow to calculate the further value and generate a game’s result. Apart from online casinos using PRNG, game providers also incorporate it when producing games to secure the fairness of the titles.

Why Is RNG Vital for Online Casinos?

RNG is a crucial part of the online gaming industry, as it promises fair play and random games. If casinos failed to provide randomness of games, the gameplay alone would soon become predictable and unappealing for players. Furthermore, if there was a pattern connected to a particular game, players would easily discover it and use it to their advantage, which would lead a casino to bankruptcy.

How Do I Know If a Casino Uses RNG?

Nowadays, online casinos have to comply with specific rules and regulations implied by the online gaming regulatory bodies. Apart from operating under a legal license, casinos must ensure that their games are fair and random.

To be able to prove the randomness of the games, online casinos hire independent audit companies in charge of testing a casino’s RNG. After such an agency determines that the outcome of games is completely random, the casino is awarded an RNG certificate of compliance.

This certificate serves as a guarantee of the casino’s integrity and can usually be found on the homepage of the site. However, in order to protect the sensitive data that the original report contains, online casino operators only share the logo of the auditor who did the testing and their seal of approval.

Is it Possible to Cheat RNG?

While this whole story about Random Number Generators making online gaming 100% fair and random is pretty much trustworthy, in theory, it is possible to go around this layer of protection. Virtually, RNG is a part of computer software, and it is well-known that everything dealing with computers can be hacked.

However, hacking casino software is easier said than done. Moreover, if we take an average casino player as an example, there’s no way they would ever be able to break into the system created by thousands of mathematicians. And even if they somehow managed to trick the software and make use of it, sooner or later they would be discovered and prosecuted for such actions.


To wrap it up, if you are thinking of playing any games in online casinos, always look for an RNG certificate of compliance. Such a sign means that casino games have been checked by an independent auditing company and are officially fair and random. Finally, even though there is a small chance that RNG can be hacked, try to avoid such actions and remember it’s always best to use online casino games only as a time-killing activity.


Chief editor and creator, Tom drives the direction of with the goal to provide the best and most honest resource for online gambling enthusiasts in Canada