Online gambling sites are not solely dependent on luck. They use advanced algorithms known as Random Number Generators (RNGs) to dictate every spin and card deal. Most online casino games are based on a Pseudo-Random Number Generator (PRNG) which guarantees random and fair results, no matter how many times you press “spin”, or place a bet. Cash-based gambling sites aren’t dependent on luck alone. They utilise advanced algorithms known as Random Number Generators (RNGs) to dictate every spin and card deal. Most online casino games are built on Pseudo-Random Number Generators (PRNG) which ensure that random and fair results are generated, no matter how often you hit spin or gamble.
Knowing how RNGs work is essential if you intend to play at casino online. We’ll walk you through the technology behind RNGs and explain the difference between PRNG and True RNG. You’ll also see how independent testing labs like eCOGRA and iTech Labs certify these systems for fairness.
Understanding RNG: The Core Technology Behind Casino Online Games
The Random Number Generator it’s unpredictable. Running in the background at online casinos, the system churns out thousands of different number sequences per second, or more. The casino ‘captures’ what’s spit out for that point in time, and that’ll dictate what happens when you place your bet.
According to the UK Gambling Commission “acceptably random” broadly means demonstrating that RNG output is genuinely random to a high level of confidence through statistical analysis. To do so it must be: uniformly distributed across the entire output range, computationally unpredictable with the next number being inherently random, and not produce the same output stream on different occasions. .
All licensed gambling sites must use third-party RNG algorithms across their games. A casino unable to offer games to players without extensive certification of the RNG shouldn’t be opened! Live dealer games are the only exception allowing physical cards, dice, or roulette wheels instead of the digital RNG.
Pseudo-Random Number Generation (PRNG) Explained
PRNGs, which are purely software-driven and generated using a formula and a seed value, dominate the online casino world due to their usage being the fastest way to produce sequences of numbers. The seed is a value from which the sequence begins to be generated. If someone knew the seed, they could predict outcomes from the generated sequence, but modern systems are selected in such a way that the sequences are indistinguishable from random numbers.
Online casinos just need PRNGs because tons of game rounds happen simultaneously at any given time. True RNG cannot pull that off. “Pseudo” refers to the method, not the model.
Each number in a PRNG sequence can be calculated from other numbers or be used to calculate other. The numbers correspond to specific positions on a reel and symbols for a slot. The algorithm applies a pre-set RTP, volatility and variance to create the final output you see on your screen.
True Random Number Generation (TRNG) vs PRNG
TRNGs generate randomness based on the measurement of unpredictable physical phenomena. Physical processes – e.g., radioactive decay, thermal noise, atmospheric noise, noise in electronic circuits, etc. Hardware implementations will require special equipment to do this.
Their source. TRNGs rely on truly random physical phenomena; PRNGs use an algorithm to run a pseudo-random path from a deterministic start. So TRNGs are unpredictable as you can’t repeat a physical process, while PRNGs are statistically random but are still deterministic.
Casinos seldom utilize TRNGs on account of the complexity of their maintenance, as well as their high cost and hardware requirements.Worse even than that, TRNGs generate random bits at comparatively low, slow rates compared to PRNGs. These TRNGs often seed PRNGs to create unpredictable generation capable of fast throughput, and are employed for crucial areas of cryptography requiring a centralized maximum of security.
How RNG Works in Different Casino Game Types
The use of RNG in slot machines can already be seen in mapping. Each symbol is assigned a value internally: Cherry = 1, Lemon = 2, Bell = 3… the system draws from a fresh set of numbers from the RNG and uses this to select the precise stopping position each reel will land on, the instant you press spin. The spinning animation is window dressing – the actual outcome was decided the moment you clicked.
Slot phenomena generated £28.20 billion ($35.40 billion) of 2023 casino revenues, making them the largest RNG-reliant vertical. The math is fairly straightforward – the RNG assigns a random number to each reel and decides where those symbols land before players even see the reels appear to stop spinning. Free spins, bonus rounds and multipliers activate in the same way, based on preset rules that link ranges of numbers to specific outcomes.
RNG in Virtual Table Games: Roulette and Blackjack
Maps RNG outcomes to the physical wheel numbers you get with virtual roulette from 0-36 on the wheel. The spin you see is the predetermined winning result after an RNG has made its decision regarding the winning number. RNGs shuffle virtual decks to get a random shuffle of the cards on each blackjack and poker hand; in RNG blackjack, the deck is re-shuffled after every hand, getting rid of counting cards entirely.
This isn’t the same kind of thing as an ordinary gambling session. A traditional casino lets you play close to 50% of a pack of cards before re-shuffling, which both creates and limits strategic opportunities. A virtual version doesn’t replicate this framework, so odds, volatility patterns and returns models are different. If you want a breakdown of RTP ranges, certification standards, risk, and who RNG tables are suitable for (casual players or advantage seekers), see our find out more guide and we’ll explain the limits, audit controls, and how this format compares to live dealer game rules and land based one.
Games That Don’t Use RNG: Live Dealer Options
Live dealer games use actual equipment and real dealers, rather than algorithms. Anonymous card shuffles, wheel spins and dice rolls play out in real-time, captured on camera. However, some hybrid live roulette games use the result of a physical spin but rely on an RNG to randomly assign multipliers to selected numbers before the wheel is spun.
RNG in Progressive Jackpot Systems
Progressive jackpots rely on RNGs to decide who wins and ensure no one can anticipate when the jackpot will strike. Each spin is unaffected by the others. The RNG manages when jackpots are triggered as players contribute and operators fund the prize pool.
RNG Fairness and Certification Standards
Third-party labs verify which RNGs gambling sites use. Based in London, eCOGRA is an independent testing agency that offers online gambling software testing & certification. iTech Labs is accredited by the National Association of Testing Authorities to ISO/IEC 17025 and ISO/IEC 17020. The lab has tested 95% of all casino online platforms since 2004. Gaming Laboratories International (GLI) has been awarded regulatory approvals to perform compliance testing in every regulated iGaming market across the globe. The company has custom software designed through collaborative efforts between in-house mathematicians and industry consultants since 1989.
What RNG Certification Process Involves
Certification starts with source code review so that the labs can appreciate RNG implementation within the game system. Labs can research the algorithm or the hardware and learn of any weaknesses or vulnerabilities known. There are statistical tests—Marsaglia’s “diehard” tests of randomness applied with a measure of statistical power on large sample sizes—that confirm that the card and number sequences produced fall into the categories of unpredictable and non-repeatable and are uniformly distributed. Certified code is also fingerprinted (i.e., “fingerprinted” is part of the digital encoding that is irreversible and avoids tampering). The satisfactory testing processes must be carried out before a game that will play in the UK can be released.
How to Check if a Casino Uses Certified RNG
Certification logos appear at the foot of licensed casinos’ websites. They can be checked through the relevant laboratory’s database; iTech Labs has a certificate database here, eCOGRA live certified operators here and GLI publish which games are certified here. Each individual certificate lists: test house, date of testing, version of RNG tested, scope of testing, and digital signatures of software tested.
But just having the logos isn’t enough for ongoing compliance. Always check that the certificate covers the same brand and software version you’re playing and whether it covers all games or only specific titles. Independent breakdowns, like the recommendations from Casiniguiden. Also, compare testing scope, explain limitations, and say which casinos provide extensive testing, which only supply minimally compliant titles, so players have a clearer risk profile to gauge before depositing.
RNG vs RTP: Understanding the Difference
RNG Random Number Generator Each time you play a game, some random values are generated that will dictate how your game round is played out. These are determined by RNG. Return-to-Player (RTP) Instead of per game round like RNG, RTP refers to the percentage of bets that are returned to players as winnings over a period. In short, through a certain amount of playing, how likely are you to win? While both RNG and RTP track wins and losers, they do so in a different way. RNG tracks individual spins or rounds, while RTP is an evaluation of the money amount an operator would pay out.
Separating RNG Facts from Fiction
The games can become streaky which, naturally, you’ll never know in advance. Roulette has 38 numbers in a double-zero game, but each appears only once every 38 spins or so, on average. But you’ll never know in advance when the next number turns up. Each round of the game is independent. The RNG doesn’t “remember” what the last result was, it doesn’t know the last result going back a decade, nor does it know what the result on the next round of games will be and “engineer” its results to match. Winning and losing streaks are natural polyfluctuation of our random ordinal, like heads flipping more often than tails with a coin which is not weighted.
The Truth About Game Outcomes and Bet Sizes
Each spin is random and independent regardless of your stake. Your chances of winning remain the same whether you bet low or high. Bigger bets give you a bigger potential amount to win or lose per spin, but don’t skew the odds in any way. The RNG selects winnings before the game animation has even started. Your stake size doesn’t affect the algorithm.
Can Players Verify RNG Fairness Themselves
Not only should there be a licence in place, which you will usually find linked at the bottom of the homepage, but you should also check the details of that licence with the relevant issuing authority, including the license number, the name of the regulator and whether the operator is licensed to operate in your country. And this is just the start. For a truly reputable casino, this will be supplemented with information on audits, payout rates and how to complain (and not just the logo in the footer).
Look for a logo from an accredited testing facility such as eCOGRA, and click on it to ensure it is connected to a current certificate and not just a graphic. Additionally, you can search the provider’s site for a list of RNG approved games, or check out the “fairness reports” section in the game settings.
If you need a structured list of what to verify — license type, audit scope, RTP ranges, bonus terms risk, and which operators provide verifiable information — see the comparison parameters outlined at Danske-Casinoer, a Denmark targeted source that also clearly states which group they are good for (regulated players) and which group should stay away from unlicensed offshore sites.
Blockchain and Provably Fair Gaming Technology
Blockchain enables “provable fairness” in which all imperceptible bets and payouts can be viewed and verified. Players can verify the RNG process including hashs and nonce values. Utilising the blockchain, the games then use provably fair systems with cryptographic algorithms allowing players to access the ledger to prove the game was not rigged. It combines a server seed from the casino, and a client seed from your browser, along with a nonce that increases with every bet. The casino reveals the original server seed after every round, allowing you to verify the hash.
