RNG in Online Casinos – How Random Number Generators Work

If you are wondering what the RNG casino software is, you’ve come to the perfect place. In the iGaming industry, randomness and fairness go hand in hand, but it isn’t always clear how these components are achieved.

Keep reading to learn how casino random number generator works, which games have it, and why it is important to find a gambling site with an RNG certification.

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What Is a Casino Random Number Generator (RNG)?

RNG CasinoThe random number generator, or RNG algorithm, guarantees transparency and fairness of online casino games. It is a sophisticated system that ensures an unbiased outcome of casino games by generating random numbers and results.

Simply put, RNG is an algorithm that generates and outputs the outcome of the action. Specifically, the generated number is mapped on the game’s outcome table, and the result of the action is then displayed on the screen.

This doesn’t sound too exciting, but professional slot developers like NetEnt, Pragmatic Play, Microgaming, and others know how to package these functions. Features like sticky wilds, cascading symbols, expanding symbols and others add more complexities.

In other words, there are other factors that influence the outcomes in RNG of online casino games and make the whole experience more dynamic.

How Does RNG in Online Casinos Work: TRNG and PRNG

There are several kinds of RNGs, but the two most commonly used are true random number generator (TRNG) and pseudo random number generator (PRNG). Each of these two relies on different mechanisms to generate random numbers.

true random number generator, also known as hardware random number generator, relies on physical phenomena, such as clock drifts, air temperature, and atmospheric noise,  which are inherently unpredictable.

Therefore, they usually have a measuring device to read the current value of some naturally occurring phenomenon. Although this is a very reliable method for generating random numbers, it’s not cost-effective, so online casinos don’t use it.

On the other hand, the pseudorandom number generator is completely computer-generated, and it’s not truly arbitrary. It uses a deterministic procedure to generate random number sequences that approximate randomness.

In general, it produces random numbers using an equation or formula. The element of randomness is the seed number added to that equation, which changes in every subsequent calculation. Then, the result of the previous equation is taken as the value of the new seed number.

However, the problem is that the initial seed number will be repeated at one point, and the cycle will reset. In other words, there is a finite number of possible outcomes, hence the name pseudorandom number generators.

To solve the issue of repetition or looping, random number generators in casinos are constantly working, even when the game isn’t played. When you press play, the last number generated is used from the memory to map the outcome of the spin/card draw/dice roll.

Discovering RNG Casino Games: Which Games Use It?

RNG Casino

Now that we covered the RNG casino definition, we should emphasize that almost all types of games use random number generators. You can take a look at the list of RNG casino games below:

  • Slot machines
  • Automatic table games
  • Video poker
  • Craps
  • Lotteries and bingo
  • Keno
  • Scratch cards
  • Crash games

RNG in casino games is used differently depending on the type of game. For card games, the number is used to map out the order of the cards in the virtual deck; in other words, the algorithm constantly shuffles cards.

In bingo and keno, the system lists out possible combinations of the numbers from the limited pool. Scratch cards work the same as slots, as they use symbols and their position on the board. The generated number just maps out the arrangement of those symbols.

How RNGs Work in Slot Machines?

As stated, RNG in slot games is constantly working, but when you press the spin button, you command the machine to map out and display the outcome. Because the reels are virtual, the designers can fit in as many symbols in there as they want.

This is relevant because only certain combinations allow you to win or win big. Suppose there is a 3-reel slot machine game with seven symbols per reel and only one payline. The number of possible combinations isn’t that high.

So, if each symbol is a number, then casino RNG software would need to generate an outcome in the range from 111 to 777 and display it. However, virtual reels have many empty spots, and symbols aren’t plain numbers and can have different functions like wild and scatter.

RNG Casino

What’s more, modern slots have multiple paylines, so the actual number of possible outcomes is measured in millions. As mentioned, they are all pre-mapped and pre-determined, and you have no agency whatsoever.

So, if you ever encounter online slots with a hold-and-spin feature or something similar, don’t bother thinking you can affect the outcome of the spin. You only affect the speed at which the reel will stop; the final outcome is loaded the moment you press the button.

Finally, online RNG casinos use the same random number generator for base game and bonus rounds. So, you shouldn’t beat your head over which box to select, as the result will be the same regardless of which one you pick.

Random Number Generators and Live Casino Games

A casino random number generator isn’t necessary for live dealer games or shows. It’s all done manually using a real deck of cards, dice, or roulette wheel.

When you play on the top live casino sites in the US, you and other players are constantly looking at the dealer and what he is doing. Studios provide multi-camera views, meaning you can keep track of all the action on the table.

Every game is streamed live and recorded, making it easy to settle any dispute using footage. Basically, it’s almost impossible to cheat, and more importantly, games work in a way that’s originally intended.

For example, blackjack, poker, and baccarat are played with six or more decks of cards, and cards aren’t reshuffled after each round. This makes card-counting strategies possible, as cards that were previously drawn are removed from the shoe.

RNG vs. RTP: Understanding the Difference

RTP, or Return-to-Player, is a theoretical percentage of stakes returned to you as winnings from a slot, table game, or some other casino game. The best slot machine games made by certified studios are transparent about RTP and players can easily find it.

But, there is a connection between casino RNG and RTP. We’ll go over a simplified example of how all online casino games calculate the RTP based on a random number generator and potential payouts.

Suppose a slot machine has only one winning combination that has a chance of appearing 1/1000 and that the payout is 1000x bet for that combination. In that case, the RTP would be 100% because the player reward is equal to the chance of that reward happening.

RTP RNG

However, payouts cannot function like that and the risk-reward ratio is slightly skewed in the casino’s favor so that they can make a profit. So, a more accurate representation of the example is that the reward would be 995x the stake.

Of course, each game has numerous winning combinations, but they are all designed in a way that the casino gets up to 8% of the money wagered. Again, win probability is always used to calculate that markup.

For instance, roulette has 1:1 bets (high-low, red-black, pair-odd) that seem 50/50. However, there are 1 or 2 zeros, and if the ball lands here the player also loses, which means a real chance of winning is around 49%.

So, the statistical RTP for roulette is 99%, and the remaining 1% is the amount of money the casino is allowed to keep.

Can You Outsmart Random Number Generator Casinos?

Not really, mainly because there is nothing to outsmart. If you look at the game’s code, you can find the section that issues a command for generating random numbers. However, the game doesn’t know what to do with those numbers until way later.

People have managed to cheat in casinos though, but it had nothing to do with RNG manipulation. The RNG in casinos is designed to be unpredictable, and trying to crack seed numbers would be a fool’s errand.

That said, people have cheated by manipulating the payout structure. In retail casinos, they would use devices that block the scanner, which verifies the amount of coins that have been paid. Even if they get a low payout combination, the machine would continue to spit out money.

The same can be done in an online casino, assuming you have access to the game’s code. You can just change how payouts are calculated and win more money. Again, the method doesn’t rely on outsmarting the RNG, and it’s still incredibly difficult to pull off.

RNG Casinos Fairness: Ensuring Integrity in Online Gaming

Players can access all virtual games for free by using the demo mode. This allows them to test RNG in online casinos and see how the payout structure works. That’s just one aspect of how these businesses handle transparency.

Casino operators regularly use independent auditors to confirm the integrity and authenticity of their RNG games. Upon confirmation, auditors grant operators a certificate that they can display on their site. Thanks to this transparency, fair gaming is guaranteed at best RNG casinos.

Casinos that try to manipulate or modify the code of a game in any way will face a hefty fine. Not only that but their license can also be revoked, which will seriously harm their business.

The Importance of RNG Certification in Online Gaming

Just like in any business, third-party quality assurance adds legitimacy to claims that the product works as intended or as advertised. In a way, someone else vouches for the game, and their reputation and business are at stake if those claims aren’t true.

RNG certificate

This also means more parties are accountable if something goes wrong. As a player, if you notice something isn’t right, you have the right to complain to those organizations. This model of shared accountability is an essential feature of safe online casinos.

Therefore, if the operator hacked the code, changed the seed number generation, or reduced the chance for bigger winnings in any way, you can take legal action against them. Companies that certify games should be on the side of players so they can help you make your case.

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Why Are RNG Audits Essential for Gaming Platforms?

A single independent RNG audit is a step in the right direction. However, having multiple certificates and audits will inspire more trust in players. There is a range of organizations and RNG tools that are used to verify the fairness of the games and their RTP.

Some of the most well-known testing services include eCogra, iTech Labs, Gaming Labs International, and BMM Testlab. These RNG testing processes consist of the following stages:

  1. An RNG in online casino games’ source code undergoes evaluation through a simulated scenario.
  2. After thousands of simulations, the system generates a graph of win-frequencies, the win-loss ratio, and the overall amount of money spent and received.
  3. This is performed multiple times for consistency.
  4. Then, the results are used to determine the approximate RTP and the game’s volatility.

These statistical tests are also known as diehard tests, and their sole purpose is to test the quality or authenticity of randomly generated numbers. There are also Chi-square tests, which are used to validate whether expected results correspond to observed results.

By verifying the statistical randomness and non-repeatability of RNGs, the agency can make sure the game is fair. They also confirm whether the RTP and random number generator in casino games adhere to the regulatory standards.

Casino RNG Testing: How Often Should It Be Done?

The best RNG online casinos undergo testing every twelve months. The same can be said for software providers who develop and code these games. Fairness certificate is also mandatory for acquiring a license.

Given that licenses need to be renewed, it’s only natural that the operators undergo multiple audits to ensure fairness.

Players can also verify the validity of the certifications. They can go to the auditor’s or licensor’s website and search their databases to see if the operator still has an active license and certification.

Why You Need to Choose a Legitimate Online Casino

Knowing that the RNG online in casino games has been tested gives you peace of mind. Because certain games have a low win rate, it can be difficult to tell on your own whether someone has tinkered with the code.

Technically, you can always check the payout table and pay close attention to payouts, but who wants to spend their time doing that? You’ve come to play and have fun, not to see if an operator is trying to pull a fast one on you.

It is crucial to find top US casino sites with RNG certification, or else you could risk playing games whose outcome is easily manipulated. In that sense, you may be playing forever without the game paying out any winnings.

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RNG vs. Live Dealer Games Comparison

rng vs live dealer

Fully digital or automated games might not feel as authentic as their live dealer counterparts. That being said, this automation does have its advantages.

RNG-based Games Live Dealer Games
Use automated software algorithms to ensure fairness. Real people manually operate the game; it’s still fair but at a slower pace.
You can play at your own pace and don’t have to wait for others to finish their turn. You need to wait for the dealer, other players, or for a place at the virtual table to open up.
You can play for free and test the game in a demo mode You can neither spectate nor play for free
Games are audited and certified You should pay attention and monitor the dealer

Are RNGs Also Used in Land-Based Casinos?

Land-based casinos use RNG algorithms across games like slot machines and video gaming terminals (poker, blackjack, lotteries, bingo, etc.). They use both HRNG and PRNG systems. As mentioned, HRNG is more costly to use which is why most machines now solely rely on PRNG.

Strategies for Playing Random Number Generator Casino Games

rng casinos

Although everything is luck-based, it is possible to play around the RNG in casino games. There are multiple tried and tested strategies that work in roulette, blackjack, baccarat, and even in slots. Here are a few suggestions:

  • Try the demo version to see how payouts work and to gauge the game’s hit frequency or volatility.
  • Start with the smallest bet possible and increase it after each loss, then return to the original value when you score.
  • Play with the smallest bet possible and make a big increase when you are on a losing streak.
  • Set a budget, and don’t bet more than you can afford; always remember there is no strategy that you can use to win at 100% consistency.
  • Test the bonus-buy feature and see if it’s worth it; this is also possible through a demo mode.
  • Claim bonuses so you can gamble risk-free; ideally, you should look for no-wager promos or a no-deposit bonus.
  • All games use RNG, but they don’t have the same rules, so there is no one-size-fits-all strategy. Make sure to go through online gambling guides for each specific game.

Expand Your Knowledge: Suggested Guides

Conclusion

RNG online casinos ensure a secure gaming environment, as they feature games whose outcomes are entirely random, unpredictable, and cannot be manipulated. All games, except live dealer games that rely on human intervention, are based on this technology.

Players should still look for certified random number generators in online casinos because it’s safer when more parties vouch for fairness.

FAQ

Can online casinos manipulate RNG to affect outcomes?

Do RNGs in online casino games follow a predictable pattern?

What are the chances of a big win if a slot hasn’t paid out recently?

Is it possible to control slot game outcomes by stopping the reels?

Responsible Gambling

RNG casinos offer a safe and transparent gaming environment, but for maximum security, you need to follow responsible gambling practices whenever you are gaming. This means setting stake limits, managing the time you spend playing, etc.

Also, if you feel like your gambling has become an issue, don’t hesitate to contact one of the following help organizations:

For help with gambling problems, you can dial 1-800-522-4700 any time of the day.

Resources

About ReadWrite’s Editorial Process

The ReadWrite Editorial policy involves closely monitoring the tech industry for major developments, new product launches, AI breakthroughs, video game releases and other newsworthy events. Editors assign relevant stories to staff writers or freelance contributors with expertise in each particular topic area. Before publication, articles go through a rigorous round of editing for accuracy, clarity, and to ensure adherence to ReadWrite's style guidelines.

Djordje Todorovic
Casino Expert

Djordje is a seasoned casino writer and a game reviewer at ReadWrite, who closely follows news in the iGaming sphere. He loves to cover industry-shaping developments and reveals during events like Las Vegas (G2E) Global Gaming Expo. He aims to provide unbiased and insightful evaluation of online/mobile slots, table games, and mini-games along with some beginner tips for the same.

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