What does RTP mean in slots?
RTP — Return to Player — is the single most useful number on a slot, and the most misunderstood. Here's what it actually means, in plain English, with the maths and the honest caveats.
The one-sentence definition
RTP is the percentage of all money wagered that a slot is designed to pay back to players over an enormous number of spins. A slot with 96% RTP is built to return £96 for every £100 staked across millions of spins. The other £4 is the house edge — the casino's mathematical advantage. House edge and RTP are just two sides of the same coin: house edge = 100% − RTP. So a 98% RTP slot has a 2% edge, and our top-rated Ugga Bugga at 99.07% has an edge of just 0.93%.
The crucial caveat: it's a long-run average
This is where most people go wrong. "96% RTP" does not mean you'll get £96 back from a £100 deposit. It's a theoretical average measured over millions of spins across all players — not a promise for your session, your day, or even your year. Over a single session, what happens to your balance is dominated by chance, not by RTP. You can lose everything on a 99% slot in twenty minutes, or hit a big win on a 94% one. The RTP only asserts itself over a volume of play no individual will ever reach.
There's a second subtlety: "wagered" means total bets placed, not your deposit. If you deposit £100 and replay your winnings, you might wager £500 or £1,000 in total — and the RTP applies to that whole turnover. This is why a deposit can disappear even at a high RTP: the edge is taken from every spin, and you're spinning many times.
RTP is only half the story — volatility is the other half
Two slots can share a 96% RTP and feel completely different to play, because of volatility (also called variance). Volatility describes how the return arrives:
- Low volatility (e.g. Blood Suckers, 98%): small wins, often. Your balance moves gently. Great for long sessions and — where eligible — clearing bonuses.
- High / very-high volatility (e.g. Money Train 3, up to 100,000x): rare wins, but potentially huge. Long dry spells are normal even with a sound RTP.
So "best RTP" and "best for me" aren't the same question. If you want a steady ride, a 98% low-volatility slot beats a 96.5% high-volatility one for your purposes — even though both are "high RTP." Always read RTP and volatility together. Our RTP database lets you filter by both at once.
The numbers most sites hide
A single RTP figure is often misleading for two reasons we cover in depth elsewhere:
- Configurable RTP — the same slot can ship in multiple RTP builds, and your casino chooses which to run. Starburst defaults to 96.09% but exists as low as 90.05%. See our configurable RTP guide.
- Bet-dependent RTP — some slots only reach their headline RTP at max stake. Mega Joker hits 99% only at the max coin bet; otherwise it's ~76.9%.
Because of these, the golden rule is: open the game's "i" / paytable screen and read the RTP for the version you're actually playing. UK-licensed casinos must make it available there.