Plenty of websites publish lists of high-RTP slots. Fewer check where the numbers come from. Copy a figure from one review site to the next a few times and errors creep in, and a game’s studio can also revise or add versions after release. For this guide every RTP was taken from the developer’s own game page or launch announcement. Where we could not find a studio figure, the game is not on the list.
Start with what RTP can and cannot tell you
Return to player is a long-run design figure. A slot set to 97% is built to pay back £97 for every £100 staked across a very large number of spins, often measured in the millions during testing. Over a session of a few hundred spins, actual results can sit far above or far below that number. RTP is a useful filter for choosing between games. It is not a forecast.
The house edge is simply the other side of the same coin: a 97% RTP slot carries a 3% house edge. If you play £1 spins and make 500 of them, you put £500 through the machine. At 97% RTP the expected cost of that play is £15. At 94% it is £30. Same stake, same number of spins, double the expected cost. That is why RTP is worth two taps of your time before you start.
In Great Britain, technical standard RTS 3 requires games to show the RTP, the house edge or the probability of winning before you commit to a bet. There is no legal minimum RTP, so the disclosure is your main protection.
The studio-verified table
| Slot | Studio | Studio-published RTP | Studio hit frequency | Studio max win (x stake) |
|---|---|---|---|---|
| Mega Joker | NetEnt | 99% (Supermeter play) | 17% | 200 |
| Book of 99 | Relax Gaming | 99% (launch figure) | Not published | Not checked |
| Jackpot 6000 | NetEnt | Up to 98.9% | 10% | 600 |
| 1429 Uncharted Seas | Thunderkick | 98.6% | Not published | Not checked |
| Blood Suckers | NetEnt | 98% | 45% | 900 |
| Steam Tower | NetEnt | 97.04% | 33% | 1,000 |
| Jack Hammer | NetEnt | 96.96% | 25% | 700 |
| Reel Rush | NetEnt | 96.96% | 28% | 1,000 |
| Dead or Alive | NetEnt | 96.82% | 30% | 8,600 |
| Big Bass Bonanza | Pragmatic Play | 96.71% | Not published | Not checked |
| Gates of Olympus | Pragmatic Play | 96.50% | Not published | Not checked |
| Sweet Bonanza | Pragmatic Play | 96.48% | Not published | Not checked |
| Starburst | NetEnt | 96.08% | 23% | 800 |
Figures were read from the NetEnt, Thunderkick and Pragmatic Play game pages and from Relax Gaming’s launch material for Book of 99, as of October 2026. Studios can change pages, so treat the in-game info screen as the final word.
Why the top two are not quite what they seem
Mega Joker
Mega Joker is a three-reel fruit machine with a twist: wins in the base game can be moved up into the Supermeter, a second level where you play at a higher stake for bigger prizes. NetEnt lists the game at 99%, and the bracket matters. The top figure depends on using the Supermeter, and the base game on its own returns noticeably less. The studio’s hit frequency of 17% also tells you that most spins pay nothing. It is a high-return game in the long run and a bumpy one in the short run, and NetEnt’s own volatility score for it is 9.9, the same as Dead or Alive.
Book of 99
Relax Gaming launched Book of 99 in 2021 as the first slot of its kind with a 99% RTP, built around a collection meter that triggers free spins once 99 books have landed. Our caution here is the general one for modern slots: studios frequently supply several RTP versions to operators. Open the paytable and check which figure the casino has loaded before treating it as a 99% game.
The low-volatility high-RTP group
If you want a high RTP without long dry spells, the useful titles are the ones where a big RTP meets a high hit frequency. Blood Suckers is the standout on paper. NetEnt publishes a 98% RTP with a 45% hit frequency and a volatility score of 2.7, which means wins arrive often and are mostly small. Its top prize of 900 times the stake is modest, and that is the trade.
1429 Uncharted Seas from Thunderkick sits in a similar spot. The studio lists 98.6% RTP and describes the volatility as low. Expanding wild ships on the middle reels do most of the work. Starburst, at 96.08% with a 23% hit frequency and a volatility score of 3.1, is lower on return but behaves similarly calmly.
Hit frequency is the number most lists leave out. It tells you the share of spins that return anything at all. A 45% figure means close to one spin in two pays something. A 10% figure, like Jackpot 6000’s, means nine spins in ten pay nothing.
The high-volatility end
Dead or Alive is the classic example of how two games with similar RTPs can feel nothing alike. NetEnt’s figures show 96.82% RTP, a 30% hit frequency and the maximum volatility score of 9.9, with a top win of 8,600 times the stake. The studio also splits the return: 71.16% comes from the base game and 25.65% from the free spins bonus. In plain terms, roughly a quarter of everything the game pays back arrives through a feature that may not trigger for a long time.
That split is one of the most useful figures a studio can publish. Starburst returns 68.7% from its main game on NetEnt’s numbers and Gonzo’s Quest 65.3%. When the main-game share is low, more of the RTP is tied up in features, and sessions get swingier. For more on reading those numbers, see our slot volatility guide.
When the internet’s number and the studio’s number disagree
Big Time Gaming’s White Rabbit is a good illustration. Third-party review pages commonly quote it at 97.72%. The studio’s own game page, when we checked in October 2026, listed White Rabbit at 96.42% RTP. We have not included it in the table because we cannot tell which version a given casino is running without opening the game there. The lesson is not that anyone is lying. It is that a slot’s RTP is a property of a specific build, and builds vary.
The same applies to many popular titles. Some studios offer operators a ladder of RTP settings for one game. The artwork, features and sounds are identical across the settings; only the maths changes. A GB-licensed casino must show you the figure for the version it runs, so the check takes seconds.
- Open the slot but do not spin.
- Tap the “i”, menu or paytable icon and look for “RTP” or “return to player”.
- Compare it with the studio figure in the table above.
- If it is lower, the casino has picked a lower-paying configuration. Choose another game or another title from the table.
- If there is no figure at all, do not play that game at that casino.
How much does a few percent really matter?
Here is the expected cost of 1,000 spins at £0.50 each, so £500 staked in total, at different RTP levels. These are averages; any real session will differ, sometimes a lot.
| RTP | House edge | Expected cost of £500 staked | Example from the studio table |
|---|---|---|---|
| 99% | 1% | £5 | Mega Joker (Supermeter) |
| 98% | 2% | £10 | Blood Suckers |
| 97% | 3% | £15 | Steam Tower |
| 96% | 4% | £20 | Starburst |
| 94% | 6% | £30 | A lower-paying version of a popular slot |
A 2% gap does not sound like much. Over the same play it is the difference between a £10 and a £20 expected cost, and it compounds every time you repeat the session.
Where RTP fits into choosing a casino
RTP transparency is one of the six checks on our non GamStop casino scorecard. A casino earns credit for loading the studio’s top configuration on popular titles and for making the figure easy to find. It loses credit if games carry no visible RTP or if the loaded version is routinely below the published standard.
Keep the stake caps in mind too: £5 a spin on online slots, falling to £2 a spin for anyone between 18 and 24. Those caps apply to every game in the table, including high-RTP ones, and they are there for good reason. A higher RTP lowers the expected cost of play. It never turns a slot into a way to make money.
Frequently asked
Which slot has the highest RTP at UK casinos?
Of the studio-published figures we found, Mega Joker (99% with Supermeter play) and Book of 99 (99% at launch) are joint top, followed by Jackpot 6000 at up to 98.9%. Availability varies by casino.
Is a higher RTP slot more likely to pay out today?
No. RTP describes the average over a vast number of spins. Volatility and hit frequency describe how bumpy the ride is. Neither predicts the next session.
Can a casino change a slot’s RTP?
Not on the fly. Operators can choose between versions a studio supplies, and must display the RTP of the version they offer. They cannot alter a game’s maths mid-session.
18+ only. Set a deposit limit before you play and stick to it. If gambling stops being fun, the National Gambling Helpline is free and open 24 hours on 0808 8020 133. More support options are on our responsible gambling page.