Casino RNG Guide: Random Number Generators Explained
Casino RNG is often mentioned when online gambling games are discussed. But what is it, what does it do and how does it impact gameplay? In this guide, we’ll explain how RNG determines outcomes, ensures fairness and how to check RNG certification.
What is a Casino RNG?
Casino RNG (random number generator) systems generate unpredictable numbers that determine game outcomes. For example, in crypto slots, the RNG system determines the position of the reels at the end of the spin. In roulette games, the RNG selects the winning pocket and so on.
This system generates random outcomes based on the game’s probabilities. At the same time, the previous results have no effect on future outcomes. Still, RNG doesn’t mean every outcome has the same probability.
The game's rules and mathematical design still determine how often specific results appear. The RNG algorithm runs constantly, generating numbers every second even when nobody is playing. When you press the button, the software “freezes” whatever number the RNG is sitting on.
What is an RNG Casino Game?
An RNG casino game is a title that uses a software- or hardware-based RNG to determine outcomes. In other words, not all casino games use RNG systems, although most new crypto casinos do. Popular RNG casino games include slots, roulette, video poker, crash games and crypto originals.
Digital (software) games usually rely on RNG technology, but live casino games still use physical cards, roulette wheels and other equipment to produce randomized outcomes.
How Does a Casino Random Number Generator Work?
The casino random number generator generates numerical combinations that the game software converts into possible outcomes. It’s a fast process that happens almost instantly, but it can be broken down into multiple steps:
- Random Value Is Generated: The RNG system generates a string of numbers using an algorithm (or physical source).
- The Value Is Converted: The game’s software identifies the number and maps it to a possible outcome, like a reel position, roulette number or card.
- Game Rules Are Applied: The game’s software determines whether the result qualifies for a payout.
- Final Result Is Displayed: The game displays the result through its visual elements, symbols or animations.
In most modern casino games, the outcomes are pre-determined, meaning the RNG locks the result as soon as you press the button. In a crash game, the plane flying and crashing is just a visual display of the predetermined result.
“I always remind players that RNG doesn’t remember whether you’ve had a winning or losing streak. I’ve seen players increase their stake after losing multiple times, thinking a payout is coming. Independent random outcomes follow the game’s programmed probabilities each round, regardless of any previous results.”
Difference Between PRNG & TRNG Explained
When reading about casino game RNGs, you might see two common terms. Here are their approaches to producing results:
- Pseudorandom Number Generator (PRNG): These use mathematical algorithms and a seed (starting value) to generate predictable sequences. Most online casino software uses them as they produce results quickly.
- True Random Number Generator (TRNG): These generators rely on physical processes like electronic noise for randomness, rather than mathematical calculations alone.
The main question is: which one is better for you as a casino player? If implemented correctly, both methods produce fair outcomes. The important thing is whether the RNG was independently tested.
Which Crypto Casino Games Use RNG?
RNG technology is used across all types of casino games, and its role varies by game mechanics. Here are the casino games that commonly use RNG, with its role explained.
Slots
The RNG determines which symbols appear and where the reels stop after each spin. Each spin produces new outcomes, regardless of previous results, even in high-RTP slots.
Roulette
In RNG roulette games, the system selects the pocket and winning number, replacing the physical wheel. All numbers have an equal chance of appearing.
Blackjack
In online blackjack games, the RNG shuffles the virtual deck and randomizes the dealt cards. You can still make important decisions like standing or hitting, but the cards are unpredictable.
Poker
The game’s RNG randomizes the cards received from the deck. When you discard or hold cards, it also determines the replacement cards dealt.
Crash
In crash games on both crypto and traditional casinos, the RNG determines the multiplier when the round ends. You must cash out before the crash, but you can’t predict or manipulate when it will occur.
Plinko
Depending on the game, the RNG can determine how the ball moves through the pegs or where it lands. The landing position is essentially your payout multiplier.
Dice
The RNG produces the result of every virtual dice roll. Depending on your bet, the generated result tells you whether you’ve won or lost.
Are Casino RNG Games Fair?
A correctly designed, implemented and tested RNG produces unpredictable results that follow the game’s probabilities. But having an RNG built into a game doesn’t guarantee its fairness. Whether the game correctly converts random values into potential outcomes, follows set game rules and pays as promised also determines its fairness.
For example, a slot game might generate random numbers as intended, but its software can still map them to incorrect winning symbols. That’s why it’s important to play games with independently tested and certified RNGs. At the same time, always look for the best payout crypto casinos.
Casino RNG Certification Explained
Certified RNG games undergo third-party independent testing by a reputable laboratory. The random number generator and the whole gaming system are evaluated to determine whether they produce fair results. Laboratories examine things like statistical randomness, unpredictability, independence, outcome mapping, game mathematics and seed security.
Certification requirements vary by jurisdiction, licensing authority and product. Multiple independent laboratories test and certify casino software. The most trusted ones are eCOGRA, Gaming Laboratories International, iTech Labs and BMM Testlabs.
RNG vs. Provably Fair Casino Games
Provably fair crypto casino games also use RNGs for determining outcomes. However, they add a cryptographic verification layer that lets you check whether the results were altered after they’re generated. Typical RNG games rely only on independent testing to verify that the results work correctly.
Like at decentralized casinos, provably fair gaming gives you more independence in verifying results using this information:
- Server Seed: A secret combination generated by the casino. The casino reveals it after the round so players can verify the results.
- Client Seed: A player’s combination generated automatically or manually used along with the server seed to generate results.
- Hash: A cryptographic fingerprint of the casino’s server seed available before the round. It ensures the provably fair casino didn’t change the server seed to produce altered results.
- Nonce: A number that represents each bet and generates different results, even with the same seeds.
“One common mistake I see players make is thinking that provably fair games offer better odds. Both of these game types use RNGs to generate random results, but provably fair titles let you verify results independently. They give you more transparency, but it doesn’t mean they are more likely to pay out.”
How to Check RNG Certification of Casino Games
Most modern crypto casinos provide information about their game RNG certification. You just need to know where to look. Here’s where you can find the evidence.
Go to the casino and look for an RNG certification or testing information. It’s usually within the footer, T&Cs, or game information page. It can be a logo for the testing lab, a link or a PDF report.
After you’ve found the RNG certificate, note the testing lab name, the company and software covered, the issue date and any reference number. Go to the official website of the issuer and look for a public listing, if available.
Open the casino game, go to its information section and look for information about the provider, RTP or certification. Remember that not all laboratories offer public certificate information, but you can always contact the lab or the game provider to confirm.
Casino RNG: FAQs
Can casinos manipulate RNG results?
Are provably fair games better than RNG casino games?
Can I beat a casino RNG?
Do RNG games favor the casino?
Vladimir is a senior iGaming writer and editor, adept at breaking down the key details of crypto casinos and sportsbooks so players don’t have to, delivering honest, player-focused information that actually matters.
