RTP & House Edge Explained
What return-to-player and the house edge really mean, how to read them, and how to find the fairest casino games.
RTP and the house edge are the two numbers that decide how fair a casino game is, and understanding them tells you more about your real chances than any strategy guide. They are two sides of the same coin.
What RTP means
RTP (return to player) is the percentage of all money staked that a game pays back over the very long run. A slot with 96% RTP returns £96 for every £100 staked on average across millions of spins. The missing 4% is the house edge — the casino's built-in margin. Higher RTP means a smaller edge and a mathematically fairer game.
Why it is a long-run average
RTP describes millions of spins, not your session. In the short term, variance dominates: you can win big or lose fast on a 96% slot, because the percentage only emerges over huge numbers of plays. High-volatility games swing harder; low-volatility games are steadier. Neither changes the long-run RTP.
How to use it
All else being equal, choose higher-RTP games — many slots publish their figure, and 96% or above is good. Table games like blackjack can have very high RTP with sensible play. Our highest RTP casinos page picks the sites with the best selection.
Keep learning
This guide is part of our wider library. To go deeper, read how to choose a casino, is a casino safe and payouts explained. Every term you meet is defined in our casino glossary, and you can put it all to work on our best online casinos ranking or the full comparison.
Frequently Asked Questions
Is this guide specific to UK players?
Yes. Everything here reflects UK Gambling Commission rules as they stand in 2026, including the 2025–2026 changes to stake limits, affordability checks and player protection. We only cover UKGC-licensed casinos.
How do I choose a good online casino?
Check it holds a current UKGC licence, look at the game range, payout reliability and support quality, then pick the safe, well-run site that fits how you play. Our full guide walks through the checklist.
How can I tell if a casino is safe?
Find its UK Gambling Commission licence number, usually in the footer, and confirm it on the public register. Avoid any site with no visible licence, one that skips verification, or one that pressures you to deposit. See is a casino safe.
Are online casino games fair?
At UK-licensed casinos, yes — games run on independently tested random number generators that cannot be altered. They carry a house edge, so they are fair but still favour the casino over time. See are casinos rigged.
What does RTP mean?
RTP (return to player) is the share of stakes a game pays back over the long run. A 96% RTP slot returns £96 per £100 staked on average; the rest is the house edge. Higher RTP is fairer. See RTP explained.
How fast should a casino pay out?
The best UK casinos process withdrawals within 24 hours once you are verified. Speed also depends on your method — e-wallets are usually quicker than cards. See our fastest payout casinos and payouts guide.
Do I have to verify my identity?
Yes — every UK casino must confirm your age and identity before paying out. With accurate details that match your ID it is usually quick. See verification explained.
Which payment methods are best?
Debit cards work everywhere; PayPal adds privacy and quick withdrawals; Apple Pay and Google Pay are fast on mobile; Pay by Mobile needs no card. Credit cards are banned for gambling. See our payment methods guide.
Did UK casino rules change recently?
Yes — slot stake limits (£5/£2 a spin), a statutory levy, and light affordability checks above a £150 monthly net loss all arrived across 2025–2026. Our 2026 rules guide explains them.
What should I do if I have a problem with a casino?
Raise it with the casino first; if it is not resolved, you can escalate free to an approved adjudicator such as IBAS. See our complaints guide.
How do I stay in control?
Set a deposit limit, treat gambling as entertainment rather than income, and never chase losses. Free help is available from the National Gambling Helpline on 0808 8020 133. See responsible gambling.
How do you stay independent?
We earn affiliate commission on sign-ups, but it never affects our rankings, which follow the published method in our methodology. We only list licensed casinos and publish every correction we receive.