Legitimate online casinos licensed and supervised by reputable authorities are not rigged. They use certified Random Number Generators (RNGs) to produce unpredictable outcomes, and those systems are tested regularly by independent labs. That said, unlicensed operators do exist and may not play by the rules — so choosing where you play is critical. Stick to recognised, reputable sites such as well-known brands that clearly display licensing and audit information.
Article Contents
Random Number Generators (RNGs)
To understand why licensed casinos can’t “rig” their games, it helps to know how outcomes are created. That’s where RNGs come in.
A Random Number Generator (RNG) is the software that drives outcomes in online casino games. It maps random numbers to concrete results — the cards in a hand of blackjack, the symbols on a slot, or the pocket hit on the roulette wheel. Certified RNGs are designed so each result is independent of the last; neither players nor the casino can predict or influence what comes next.
Reputable regulators require regular third-party testing (e.g., eCOGRA, GLI, iTech Labs) to verify that the RNG outputs are statistically sound and that the game behaviour matches the approved maths model.
Return to Player (RTP)
Once you know results are random, the next question is: how much are games designed to return over time? That’s where RTP comes in.
RTP (Return to Player) is the long-run percentage of total stakes a game is designed to pay back to players. It’s calculated over very large numbers of spins/hands and is a guide to expected return — not a promise for any single session. Outcomes remain random via the RNG; RTP simply reflects the underlying pay-table maths of the casino game.
How RTP Is Set
- Developer model: Studios design each title’s maths (hit rate, features, pay table) to produce a target RTP.
- Multiple RTP profiles: Many slots ship with several approved RTP versions (e.g., ~96%, ~95%, ~94%). Operators choose which version to host.
- RNG stays fair: Choosing a lower RTP profile lowers long-run expected returns but does not allow anyone to “control” individual outcomes — results are still generated by an independently tested RNG.
Why RTP Matters
Even small differences in RTP compound over time. This is especially important when meeting wagering requirements on bonuses:
- Total at risk: 2,000 spins × £1 = £2,000 wagered
- At 96% RTP (4% house edge): expected loss ≈ £80
- At 94% RTP (6% house edge): expected loss ≈ £120
An extra two percentage points costs ~£40 on the same play volume — and the gap widens with higher stakes or longer wagering. RTP doesn’t predict short-term results, but over volume it materially affects expectations.
Can Casinos Change RTP?
Licensed operators can select (or later switch to) any developer-approved RTP profile for a game. Under strong regulation, the current RTP must be displayed in the game’s info/help screen. This is one reason to prefer sites overseen by top authorities: see our regulator overview and stick to reputable casinos.
How to Check RTP
- In-game info: Open the “i”, paytable, or help section; licensed sites publish RTP there.
- Developer pages: Studios often list RTP ranges for each title.
- Regulator expectations: Authorities like the UKGC, MGA, and Isle of Man GSC require accurate, accessible game information. If RTP isn’t shown, treat that as a red flag.
The House Edge
RTP and house edge are two sides of the same coin. While RTP shows what games return to players, the house edge represents the casino’s built-in advantage.
The house edge is expressed as a percentage, calculated as 100% − RTP. With blackjack played optimally the edge can be around ~0.5–1% (rule-dependent), while some slots may exceed 5–10%.
Crucially, a house edge doesn’t mean the casino wins every time or that you’ll lose in the short run. Results are random; the edge shows through over many bets. Keep this in mind when setting expectations and stakes.
The Importance of Using Regulated Casinos
Choosing a regulated casino isn’t just about avoiding scams. Strong regulators set standards for game fairness, financial security, and responsible gambling protections.
When choosing a site, look for licensing from authorities such as the United Kingdom Gambling Commission, the Malta Gaming Authority, or the Isle of Man Gambling Supervision Commission. Verify the licence details on both the casino’s footer and the regulator’s website.
Responsible Gambling Tools
Licensed sites must provide tools that help players stay in control. These include deposit or loss limits, reality checks, time-outs or self-exclusion, and detailed activity statements. Use these proactively to manage your spend and session time.
If you ever feel your gambling is causing harm, seek help immediately: problem gambling support resources.
“I Think I Was Cheated” — Common Misconceptions
Many players worry they’ve been cheated after a bad run. In reality, a few psychological traps explain these feelings:
- Selective memory: Losses feel sharper than wins, so bad runs stick in mind.
- Misreading probabilities: Without a grasp of variance, normal downswings feel suspicious. See our explainer on variance in betting.
- Unrealistic expectations: The house edge means the casino has a long-term advantage. Learning how to play and each game’s rules helps align expectations.
- Bad actors elsewhere: A poor experience with an unlicensed site can colour perceptions of legitimate operators.
Disputes & ADR
If you believe an issue goes beyond bad luck, regulated operators are required to provide a clear complaints process. If support doesn’t resolve it, you can escalate to an approved ADR (alternative dispute resolution) provider — an independent body that reviews evidence from both sides. Regulator websites list the ADR assigned to each operator and explain how to submit a case.
Key Takeaways
- Licensed ≠ rigged: Reputable, regulated casinos use independently tested RNGs and approved game maths.
- RTP matters: It’s the long-run return percentage of a game; small differences compound over many spins, especially with bonuses.
- Operators can select RTP versions: Within developer-approved options — but they must display the current RTP accurately.
- House edge persists: Results are random in the short term; the casino’s advantage emerges over volume.
- Protect yourself: Choose strong regulators, use responsible-gambling tools, and know the ADR route for disputes.
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