How Does an RNG Work? – Expert Explanation Updated for 2024

In the beginning stages of the online gambling industry, in the absence of clear regulations and independent testing labs, rigged content was a prevalent worry for players. The emergence of the RNG technology completely changed the game and made our sessions fair and transparent. But how does an RNG work exactly? Our experts explain.

What Is an RNG and How Does It Work?

The acronym “RNG” stands for “Random Number Generator”, and refers to a computer algorithm that generates sequences of numbers or symbols that can’t be predicted in advance through any means. This technology is used in various industries where it’s paramount to produce unpredictable results, such as security applications, cryptography, and casino games.

In the context of online gambling, RNGs are used solely for casino games whose outcomes are based entirely on luck. Here we’d include titles like online slots, roulette, bingo, video poker, and lottery. Even though they are manned by a game coordinator, some hybrid titles such as may also include RNGs, especially if one bonus round requires the drawing of random numbers to determine the winners.

The RNG technology is the powerhouse that guarantees fair game outcomes, equal odds for all participants, and increased transparency from software providers and casino operators alike.

How Does the RNG work in Slot Machines and Other Games?

Let’s start with slot machines, because they are the most compelling examples to explain how an RNG works. When you click the spin button on these games, the algorithm generates random numbers every millisecond, which correspond to the different symbols on the reels. The result of the next spin is never connected with the previous one, so every outcome is completely dictated by pure chance.

Similarly, RNGs are used in online table games to generate various impartial outcomes, for example the result of a coin toss or a dice throw, the next card from the deck in video poker, the lucky numbers at roulette, bingo or lottery, and so on.

Practically speaking, RNGs are either computer algorithms or hardware devices, though they both fulfil the same basic task. In the hardware version, the RNG appears as a small microchip, which can be installed in slot machines, video poker, or keno machines. It’s incredibly complex, because it can generate values ranging from 0 to 4 billion, 24/7, as long as it’s powered

Different Types of RNGs

Depending on their applicability to different industries and how they produce end results, two main types of RNGs exist. Below we explain how each one works.

True Random Number Generators (TRNG)

TRNGs are the most mathematically-sound and sophisticated algorithms because they can’t be cracked or manipulated by any outside force. They are based on hardware devices, which is why they’re also named hardware random number generators (HRNGs).

Because we’re referring to a physical random number generator, it uses a device that replicates these results from outside forces that can’t be predicted. For example, the device may use natural phenomena to achieve true randomness, such as atmospheric noise, air temperature, or subatomic particles. These are ideal variables for any random system. Once they are measured, the device attributes values to them and produces unforeseeable results.

TRNGs are mainly used in industries where it’s essential for the outcomes to be 100% unpredictable, without the possibility to re-run number sequences. As such, you’ll find them in gambling machines, cryptography, and data encryption, among others.

Pseudo Random Number Generators (PRNG)

A PRNG is less reliable, considering that the numbers only appear random, but are actually predetermined.

That’s because PRNGs use an initial value called “a seed” or “a key”. This key determines what possible outcomes can be produced by the generators. In theory, if you know the seed and have a thorough understanding of the mathematical principles involved, you could determine what combinations will result. However, it’s much harder to do so in practice, and it involves advanced technical skills and time to analyse the algorithm.

PRNGs are primarily utilised to determine simulations, like the Monte Carlo method, which requires large amounts of randomly-generated numbers for statistics, but they’re also prevalent in certain electronic games.

How Does an RNG Affect Casino Games

As we previously mentioned, an RNG is solely used for luck-based games. To clarify, we are strictly referring to the online or video version of the games, not the live-dealer ones. For the latter, the croupier assumes the role of shuffling cards and coordinating other aspects of the game.

Below, we’ll show you exactly how the RNG works within each popular casino game, and why it’s instrumental in guaranteeing the fairness of your next session.

RNG in Slots

How does RNG work in slots? Well, if you’re playing video slots, the RNG algorithm basically simulates the outcomes produced by the microchip counterpart, which you’ll find installed in physical slot machines.

As such, neither the player, nor the house, can manipulate the game results to give themselves an edge. The present result (win or loss) is not dependent on a past outcome, so there’s no clear sequencing you can guess or anticipate.

Upon spinning the reels, the RNG starts producing hundreds of combinations per second, then chooses a set of symbols to appear on the screen, which generate monetary wins according to the paytable. This randomisation occurs 24/7. Moreover, since the software is impartial, it dispels the concept of hot/cold slots. To recap, these two terms are widely used in gambling communities. “Hot” slots refer to active games that have handed out regular payouts spin by spin in the recent past, while “cold” slots haven’t created any winning combinations in a while. In actuality, that’s just how the RNG algorithm works in practice.

Do remember that personal discernment is just as important. Only play on the top real-money slots sites, where you can trust the fairness of the RNG algorithm. These platforms are regulated by top industry authorities like the MGA or Curaçao, and some have also been subjected to independent software testing. In fact, be mindful that unregulated or rogue sites often present counterfeit copies of slot games from legitimate providers, only with skewed RNGs, RTPs, or both, so they should be avoided at all costs.

RNG in Online Roulette

In online roulette, this technology is used to generate an unforeseeable outcome for each spin of the wheel. The algorithm compiles random sequences and, upon spinning the roulette wheel, automatically picks one of them from this range to be the winner of the round. According to the game rules, the winner can either be a colour (red/black), a single number, a number type (high/low, odd/even), and so on.

RNGs are used for all popular online variations you can find on the top real-money roulette sites, including the European, American, and French variants.

RNG in Online Blackjack

As opposed to live-dealer blackjack, where the croupier shuffles the cards and hands them out to the players, in online blackjack, the RNG algorithm takes care of this aspect. After setting your bet, upon clicking on the “Deal” button, the technology ensures a random draw for both your starting cards and the dealer’s.

Many beloved versions of the game available on the top real-money blackjack sites make use of this technology, such as Single Deck Blackjack, Multihand Blackjack, American Blackjack, and European Blackjack.

RNG in Video Poker

Live poker is played alongside actual opponents who make their decisions in real time. On the other hand, video poker is a single-player game, meaning that you battle the house, which is essentially the RNG algorithm.

Video poker uses elements of regular poker, but also slot machines. Once again, your aim is to create the best five-card poker hand.

After setting your bet, the algorithm will randomly select playing cards on the screen that you can either hold or discard to create the best hand. As you’ve probably gathered, on trustworthy, regulated online gambling platforms, the casino can’t manipulate the algorithm to draw weaker cards for the player.

RNG in Lottery and Similar Titles (Video Bingo, Keno, Scratchcards)

Although it’s a popular game of chance, lottery has been subjected to the biggest controversies since inception when it comes to fairness.

Participants feared that organisers would rig the results or hand out the lucky numbers in advance to a selected group of people. In actuality, both the land-based and online version of lottery are reliant on the RNG technology. That means no rigging can occur, because the most important criteria for the proper organisation of the game are chance and unpredictability. Thankfully, that also removes any possibility of human error.

Likewise, RNG is used to determine and reward winning patterns at video bingo. It’s also utilised to decide whether or not you get a matching numbers sequence on an online scratchcards game.

Can I Trust the RNG? Key Arguments

In order to have peace of mind and know that the RNG algorithm functions properly, it’s essential to only register on legal online casinos. These are frequently subjected to third-party audits from testing authorities, but also reviewed by regulatory bodies to make sure their licence can remain in good standing.

The purpose of RNG audits is to confirm that the games are incorruptible, generate 100% random results, and are fair to players. If all of these verifications are passed with flying colours, you can trust the online casino site or software provider in question. That also means you won’t be able to beat the RNG yourself, because it’s bulletproof.

Here are more details about the key players who are either allowed to verify the RNG fairness, or reject operators who don’t have a certificate:

• The Malta Gaming Authority (MGA) – This renowned gambling authority has a special RNG request for all licensees who add new games onto their platforms. If the RNG is not approved in advance, they must supply a valid RNG certificate.
• BMM TestLabs – This is the oldest and most well-established independent testing lab in the world, with over 40 years’ experience. It provides third-party verifications for a wide range of verticals, including sports betting, iGaming, lottery, and tribal gaming. To be approved, the gaming content must meet sophisticated technical standards in terms of the RNG algorithm and its implementation, plus also abide by jurisdictional laws.
• iTech Labs – Founded in 2004, iTech Labs is an accredited testing laboratory for the online gambling industry, serving clients in numerous jurisdictions worldwide, such as Europe, Asia, and Australia. The company tests both hardware RNGs and virtual ones, through a very thorough process that includes statistical randomness; seeding, re-seeding, and cycling; unpredictability and non-repeatability. It also performs regular RTP and RNG audits on global casino operators.

The key takeaway to remember is that the top online casinos that take player safety and satisfaction seriously generally display seals of approval from independent testing authorities. This serves as an extra incentive to register, because members know they will be protected and will benefit from fair odds across the entire games catalogue.

Usually, you can find these certification stamps listed at the bottom of the homepage, and they typically belong to either of the authorities we listed above, or similar ones like GLI (Gaming Labs International) or eCOGRA (eCommerce Online Gaming Regulation and Assurance).

How RNGs Work – Our Verdict

If you engage in online casino games on the regular and had any worries about security, transparency, or your odds to win, understanding how RNGs work can definitely ease your concerns. We hope our in-depth guide helped explain the topic in easy terms. Oh, and don’t forge: only play on regulated platforms, so you never have to worry about RNG fairness!

The Workings of an RNG – Our Sources

1. Casino Gambling For Fun and Profit – This book by J. Edward Crowder analyses how the RNG algorithm is implemented in video poker and the gameplay implications.
2. Internet Gambling: The Relationship between Legality and Integrity – In this paper, author Anthony Cabot emphasises the importance of monitoring the activity of online casinos to ensure the RNG algorithm works as intended.
3. How do slot machines and other electronic gambling machines actually work? – Authors Nigel Turner and Roger Horbay performed an extensive research into how slot machines function, with a focus on the core differences between random vs pseudorandom algorithms.
4. Prior Approval Requirements from The Malta Gaming Authority – This reputable European regulator asks licensees to submit a valid RNG certificate for any new games added to their platforms.