With so many online casino games to pick from, it is reasonable to ask whether they are genuinely fair or if the odds are stacked against you. Terms like random number generator (RNG), house edge, and game audits can sound technical, which is why myths still crop up.
This guide clears up the confusion. It explains how RNGs decide outcomes, what house edge really means, how regulators and auditors keep things in check, and how you can verify that games are being run properly. It also touches on “provably fair” systems and how live dealer games differ from digital ones.
If you choose to play, treat it as entertainment, set sensible limits, and only use licensed operators.
What Is A Casino RNG And How Does It Work?
An RNG, or random number generator, is software that produces unpredictable outcomes for each game round. Online slots, roulette, and digital table games all rely on an RNG to decide results independently of past or future rounds.
The RNG constantly generates long strings of numbers, and the game maps a number to a specific outcome. In a slot, for instance, the chosen number corresponds to the exact symbol positions that land on the reels. Because every round is generated afresh, patterns cannot be tracked or influenced.
Licensed casinos use certified RNGs that are tested by independent labs to confirm they work as intended. This external oversight exists to make sure the outcomes you see match the rules built into each game.
Curious how that randomness looks in practice across different titles? That is where slots and table games take centre stage.
How Random Are Slots And Table Games?
Online slots and digital table games use an RNG to determine results. Each spin, card, or dice roll is produced on its own, without any memory of what happened before. Past outcomes do not inform the next one, which is why so-called “hot” or “cold” streaks are not a reliable guide.
In slots, the RNG selects the symbol positions for every spin. In digital table games, it controls the card order, dice values, or the roulette number. This all happens instantly and without human input.
Live dealer games are different. A real croupier shuffles cards or spins a physical wheel, with cameras streaming the action. The randomness comes from the physical process, not software, but the principle is the same: outcomes are not prearranged.
If you want reassurance that this is happening as described, it helps to know how testing works behind the scenes.
RNG Vs House Edge: What Is The Difference?
RNG and house edge do two very different jobs. The RNG decides each outcome unpredictably, ensuring no one can forecast the next spin or deal. It is about fairness at the point of each result.
House edge is the built-in mathematical margin that a casino expects to retain over a very long time. It is expressed as a percentage unique to each game and ruleset. A game with a 2% house edge is designed so that, across a vast number of bets, about £2 of every £100 staked may be retained by the operator.
The key point is that the house edge does not interfere with randomness. Individual outcomes are still unpredictable; the edge emerges only over many rounds because of the way the game is structured.
So who confirms that the systems delivering those outcomes are working properly?
How Do Regulators And Auditors Test RNG?
Regulators require operators to use RNGs that meet strict technical standards. To verify this, independent testing labs examine both how the software behaves and how the code is written.
Auditors run large-scale statistical tests across thousands or millions of rounds to check that results align with the game’s rules and expected distribution. They also review the source code and security controls to make sure results cannot be intercepted, altered, or biased.
Only games that pass these checks are approved for use. You can usually find the name of the testing lab in the site’s footer or fairness page, alongside licensing details. Regular re-testing keeps those assurances current.
With the testing process in place, it is worth asking the next question head-on.
Can Casinos Manipulate RNG Results?
Reputable operators do not control RNG outcomes. The software is certified by third-party labs, monitored by regulators, and subject to ongoing checks. Any attempt to alter results would put the operator’s licence at risk and would likely be detected through audits and player dispute processes.
This mix of technical certification, regulatory oversight, and potential penalties creates strong incentives to keep systems compliant. If a site is properly licensed and transparent about testing, manipulation is not in its interest.
Once you know the outcomes are genuinely unpredictable, it helps to understand how slot behaviour can still vary from game to game.
Understanding RTP And Volatility For Slots
RTP, or Return to Player, is a theoretical long-term percentage indicating how much of total stakes a slot may pay back over time. For example, a 96% RTP suggests that across a very large number of spins, about £96 of every £100 staked could be returned in prizes. That figure is not a promise for any given session.
Volatility describes how a slot distributes its returns. Low volatility games tend to produce smaller wins more often. High volatility titles may deliver larger prizes, but less frequently. Neither setting changes the randomness of each spin; it simply shapes the pattern of outcomes over time.
These figures are set by the game developer and published so players can choose the style of play that suits them.
If you want to see evidence that a site’s games are set up correctly, there are a few simple checks you can make.
How To Check If A Casino's RNG Is Legitimate?
Start with the licence. Legitimate sites display their licensing information in the footer, along with links to regulatory details. Next, look for the seals of recognised testing labs such as eCOGRA, iTech Labs, or GLI. Clicking these often leads to a certificate page confirming the scope and date of testing.
Many operators explain their auditing process in a fairness or help section, including how often games are tested. If anything is unclear, ask customer support for the latest certificates or a link to the lab’s verification page. A genuine operator will provide this without fuss.
You may also encounter a different approach to verification entirely, especially on crypto-focused platforms.
What Is Provably Fair And Does It Apply To Online Casinos?
Provably fair systems use cryptographic methods to let players verify that a game round was not altered after it was created. The site and the player each provide a value, often called a seed, which feeds into a hash. After the round, the player can check that the published result matches the inputs.
This approach is common on some cryptocurrency-led platforms. It provides transparency in a different way from the traditional audit model. In the UK market, most regulated casinos rely on certified RNGs and independent lab testing rather than provably fair tools, as the regulatory framework already sets strict testing requirements.
Whichever model a site uses, the important part is that the method is explained clearly and can be checked.
Live Dealer Games And Randomness: How They Differ
Live dealer games replicate the feel of a land-based venue. Outcomes come from physical processes: real cards, shuffled and dealt, or a roulette ball spun around a real wheel. Studios use multiple cameras, trained dealers, and procedures for shuffling and equipment checks, all monitored for integrity.
Because the randomness is physical, the fairness assurances are operational rather than software based. Providers follow detailed rules for dealing, shuffling, and handling equipment, and their studios are routinely audited to confirm those procedures are followed.
Before joining a table, it is worth glancing at the provider’s name and the site’s licence details. These give confidence that the stream you are watching is being run to agreed standards.
What To Do If You Suspect A Game Is Rigged?
If something does not look right, keep a record. Save screenshots, note the time, and write down the game title and what raised your concern. Clear details make it easier to investigate.
Contact the casino’s support team and use the formal complaints route. Licensed operators must have a process for reviewing issues and replying within set timeframes.
If the outcome is unsatisfactory, you can take the matter to an approved Alternative Dispute Resolution provider, who will assess the case independently. Serious concerns about compliance can also be reported to the regulator.
If you choose to play, set limits that fit your circumstances and never stake more than you can afford to lose. If gambling starts to affect your well-being or your finances, support is available. GamCare and GambleAware offer free, confidential help.
**The information provided in this blog is intended for educational purposes and should not be construed as betting advice or a guarantee of success. Always gamble responsibly.