Do UK Casinos Use Different RTPs for the Same Slot?
I checked the RTP shown for 13 familiar slots at 11 UK casinos. The numbers were not always the same, even when the title on the screen was. Here is what I found, including the cases that were not quite as straightforward as they first looked.
Yes, and by more than you might think. Every one of the 13 games showed more than one RTP figure across the 11 casinos. Legacy of Dead appeared at 91.51%, 94.51% and 96.58%, all settings listed by its developer. In theory, at 91.51% you’d expect to lose £84.90 for every £1,000 staked over the long run. At 96.58% it’s £34.20.
RTP, or return to player, is the share of stakes a game is designed to pay back over a very long run. It won’t tell you what happens in one session, but it is the simplest measure of how much a game costs to play. I’ve worked in this industry since 2005 and I still didn’t realise how much it could vary for the same game until I sat down and checked.
What I found across 13 games
The clearest case is Legacy of Dead: 91.51%, 94.51% and 96.58% depending on the casino, a spread of 5.07 percentage points. All three figures are in Play’n GO’s own settings document, which makes it the widest spread in the study where both ends are documented by the developer.
The casinos fell into a pattern too. Slots Temple showed the highest figure, or joint highest, for all 13 games, and the outright highest for seven of them. At the other end, William Hill showed the lowest or joint-lowest setting for 11 of the 13 games, Virgin Games for 10 and LeoVegas for 9. Across these 13 games, the same casinos repeatedly appeared towards the top or bottom of the recorded RTP ranges. That was one of the clearest patterns in the results.
Not every difference has a tidy explanation. Eye of Horus turned up in different builds, Sweet Bonanza shows ranges rather than one figure, and Starburst produced a 98.05% reading I could see but couldn’t match to NetEnt’s documents. The table shows what was on screen; the sections after it explain each case.
| Slot game | Observed RTP figures | Spread | How to interpret |
|---|---|---|---|
| Big Bass Bonanza | 92.05% to 96.71% | 4.66 pp | Supplier and UK-certified configurations |
| Big Bass Splash | 92.05% to 96.71% | 4.66 pp | Client displays; RTP tiers not independently reconciled |
| Bonanza Megaways | 91.21% to 96.00% | 4.79 pp | Client displays; developer tiers not reconciled |
| Book of Dead | 91.25% to 96.21% | 4.96 pp | Documented Play’n GO settings |
| Eye of Horus | 90.25% to 96.31% | 6.06 pp | Mixed builds; RTP tiers not reconciled |
| Fishin’ Frenzy | 92.00% to 96.12% | 4.12 pp | Mixed builds; RTP tiers not reconciled |
| Fluffy Favourites | 90.187% to 95.388% | 5.20 pp | Not found at two casinos; tiers not reconciled |
| Gates of Olympus | 92.10% to 96.50% | 4.40 pp | Earlier and later UK-certified settings |
| Legacy of Dead | 91.51% to 96.58% | 5.07 pp | Documented Play’n GO settings |
| Rainbow Riches | 92.02% to 95.00% | 2.98 pp | Mixed platforms; RTP tiers not reconciled |
| Starburst | 92.05% to 98.05% | 6.00 pp | 98.05% mathematical version unresolved |
| Sugar Rush | 92.03% to 96.50% | 4.47 pp | Supplier and later UK-certified settings |
| Sweet Bonanza | 92.04–92.10% to 96.49–96.60% | Not comparable | Client rules ranges; applicable mode unresolved |
Differences are expressed in percentage points. Fluffy Favourites retains its three-decimal readings in the full matrix, with the spread rounded to 5.20 pp. Sweet Bonanza has no single spread because its rules give RTP ranges, not one identified active value.
Where the source evidence stops: For Big Bass Splash, Bonanza Megaways, Eye of Horus, Fishin’ Frenzy, Fluffy Favourites, Rainbow Riches and Sweet Bonanza, I verified the rules and help screenshots but haven’t matched every RTP tier to a full set of developer or certification documents, so for those games the table shows what was displayed, not certified ranges.
Where the differences come from
Legacy of Dead and Book of Dead: settings the developer lists
Legacy of Dead gives the cleanest answer. Four casinos showed 91.51%, six showed 94.51% and Slots Temple showed 96.58%. Play’n GO’s Legacy of Dead Rules and Settings (GRS1611) lists all three, so this is simply casinos picking different documented settings, even though the screenshots don’t show each casino’s exact build.
Book of Dead follows the same pattern, with 91.25%, 94.25% and 96.21%, all listed in Play’n GO’s Rich Wilde and the Book of Dead Rules and Settings (GRS0595). It’s a good reminder that quoting one RTP for a popular slot can be misleading.
The theoretical cost difference is substantial, as the example at the start of this study shows, though it says nothing about the outcome of any one session. There’s more on the games themselves in the Legacy of Dead and Book of Dead guides.
Big Bass Bonanza, Gates of Olympus and Sugar Rush: UK certification records
Big Bass Bonanza showed four figures: 92.05%, 94.02%, 94.50% and 96.71%. Pragmatic Play’s supplier data lists 96.71%, 95.67% and 94.50%, and the UK certification material adds 94.02%, 92.05% and a 90.63% setting. I didn’t come across 95.67% or 90.63% at any of the casinos. The Slots Temple 96.71% is on page three of that game’s rules.
Gates of Olympus showed 92.10%, 94.50% and 96.50%. A 2021 UK certification covers 94.50%, 95.50% and 96.50%, and a 2024 UK Remote report adds 92.10%. Sugar Rush is almost identical: 92.03%, 94.50% and 96.50% on screen, with the first three settings in its supplier material and 2022 UK certification and 92.03% in a March 2024 UK Remote report. Neither game showed its 95.50% setting anywhere in my sample.
Big Bass Splash and Fluffy Favourites
Big Bass Splash showed three figures, from 92.05% to 96.71%. Betfred’s 96.71% stands out against its other readings, but it’s there in the game’s own rules screenshot. I can’t tell from the screenshots alone whether every casino was running otherwise identical maths.
Fluffy Favourites showed 90.187%, 93.29% and 95.388% across nine casinos. I couldn’t find it at Betfred or Sky Vegas, and William Hill’s version came up through its bingo site, so I’ve left the two missing cells as n/a rather than guess.
Where the numbers need a closer look
Eye of Horus and Fishin’ Frenzy: different builds
Eye of Horus runs from 90.25% to 96.31%, a 6.06-point spread on paper. But these aren’t all the same build. William Hill’s 90.25% version is 1.7.4.1 and MrQ’s 94.00% is 1.7.4.2_HOTFIX_2, both newer 1,500x maximum-win versions showing different RTPs. Meanwhile bet365 (1.6.2.6) and Slots Temple (1.7.0.2_hotfix_4) both show 96.31%, and several other builds aren’t identified. So the build number doesn’t tell you the RTP, and the 6.06-point figure describes what was displayed, not one build set to different levels.
Fishin’ Frenzy is similar. MrQ showed 94.00% on a newer version, while bet365’s 96.12% screen identifies 1.6.1.3_Hotfix_1, the same version reported at Slots Temple. The readings run from 92.00% to 96.12%, but I couldn’t identify the build at every casino.
Rainbow Riches and Bonanza Megaways: different sources
Rainbow Riches showed 92.02%, 93.99% and 95.00%. Paddy Power runs it through a Playtech/Virtue Fusion client, while bet365 and Slots Temple show the classic Barcrest/Scientific Games version. That’s a genuine platform difference, though it doesn’t explain every figure on its own.
Bonanza Megaways ranged from 91.21% to 96.00%. One reading needs a footnote: Betway’s 95.98% came from a developer-hosted help page that opened alongside the casino game, not from the game’s own rules screen. It’s neither the highest nor the lowest, so the spread stands.
Sweet Bonanza: a range, not one figure
Sweet Bonanza’s rules show one of three ranges: 92.04–92.10%, 95.45–95.50% or 96.49–96.60%. I haven’t established which value within a range applies to which betting mode, so I show the whole range rather than quote the top figure as if it were the one in play.
Starburst: a figure I can show but not explain
Slots Temple’s Starburst help screen showed 98.05% on 25 September, and the same figure again when I went back on 4 October. The reading is solid. What I couldn’t do is match it to any configuration in the NetEnt material I have, so it’s the one figure in the study I can show but not explain. There’s a smaller oddity too: bet365 and Paddy Power showed 96.09%, while NetEnt’s current game page says 96.08% and an older OpenBet document about 96.10%. That may just be rounding.
The full casino-by-casino results
Here is everything: 13 games across 11 casinos, with every figure backed by a dated screenshot. Casinos are listed alphabetically. The lettered notes flag the cells that need context, such as a different build or a figure taken from a help page.
Swipe sideways within the table to compare casinos. The game-name column stays visible where your browser supports it.
| Slot game | bet365 | Betfred | Betway | LeoVegas | MrQ | Paddy Power | PlayOJO | Sky Vegas | Slots Temple | Virgin Games | William Hill |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Big Bass Bonanza | 94.50% | 94.50% | 94.02% | 92.05% | 94.02% | 94.02% | 94.02% | 94.02% | 96.71% | 92.05% | 92.05% |
| Big Bass Splash | 94.60% | 96.71% | 94.60% | 92.05% | 94.60% | 94.60% | 94.60% | 94.60% | 96.71% | 92.05% | 92.05% |
| Bonanza Megaways | 96.00% | 96.00% | 95.98%a | 94.33% | 94.33% | 96.00% | 96.00% | 96.00% | 96.00% | 91.21% | 96.00% |
| Book of Dead | 94.25% | 94.25% | 94.25% | 91.25% | 94.25% | 94.25% | 91.25% | 94.25% | 96.21% | 91.25% | 91.25% |
| Eye of Horus | 96.31% | 96.31% | 92.04% | 92.04% | 94.00%b | 96.31% | 92.04% | 96.31% | 96.31% | 92.04% | 90.25%b |
| Fishin’ Frenzy | 96.12% | 96.12% | 92.00% | 92.00% | 94.00%c | 96.12% | 92.00% | 96.12% | 96.12% | 92.00% | 92.00% |
| Fluffy Favourites | 93.29% | n/a | 95.388% | 95.388% | 93.29% | 95.388% | 90.187% | n/a | 95.388% | 93.29% | 93.29%d |
| Gates of Olympus | 94.50% | 94.50% | 94.50% | 92.10% | 94.50% | 94.50% | 94.50% | 94.50% | 96.50% | 92.10% | 92.10% |
| Legacy of Dead | 94.51% | 94.51% | 94.51% | 91.51% | 94.51% | 94.51% | 91.51% | 94.51% | 96.58% | 91.51% | 91.51% |
| Rainbow Riches | 95.00% | 93.99% | 95.00% | 92.02% | 93.99% | 95.00%e | 95.00% | 95.00% | 95.00% | 92.02% | 92.02% |
| Starburst | 96.09% | 94.05% | 94.05% | 94.05% | 94.05% | 96.09% | 92.05% | 94.05% | 98.05%f | 93.05% | 92.05% |
| Sugar Rush | 94.50% | 94.50% | 94.50% | 92.03% | 94.50% | 94.50% | 94.50% | 94.50% | 96.50% | 92.03% | 92.03% |
| Sweet Bonanzaranges | 95.45–95.50% | 95.45–95.50% | 95.45–95.50% | 92.04–92.10% | 95.45–95.50% | 95.45–95.50% | 95.45–95.50% | 95.45–95.50% | 96.49–96.60% | 92.04–92.10% | 92.04–92.10% |
- a. Bonanza Megaways, Betway
- 95.98% from a separate developer-hosted help page, not an embedded in-game RTP screen.
- b. Eye of Horus
- William Hill 90.25% and MrQ 94.00% are recorded on newer builds; other game versions differ or are not fully identified.
- c. Fishin’ Frenzy, MrQ
- 94.00% is associated with a newer version; do not assume the same mathematical build as the 96.12% client.
- d. Fluffy Favourites, William Hill
- The rules were captured through William Hill’s Bingo interface.
- e. Rainbow Riches, Paddy Power
- A Playtech/Virtue Fusion client; other screenshots include classic Barcrest game clients.
- f. Starburst, Slots Temple
- 98.05% was screenshot-verified twice but remains unresolved against the available developer configuration evidence.
Can a casino change the RTP while you play?
A casino can’t simply adjust a game’s RTP in response to how you’re playing. That’s different from offering a version of the game with a different RTP setting in the first place. The Gambling Commission’s RTS 7A and 7D ban games from adapting to how someone has been playing, and restrict changes to probabilities and payouts while a game is live, apart from stated exceptions that customers must be told about.
How I checked the games
On 24 and 25 September 2026 I logged in to my verified real-money accounts at 11 UK casinos: bet365, Betfred, Betway, LeoVegas, MrQ, Paddy Power, PlayOJO, Sky Vegas, Slots Temple, Virgin Games and William Hill. At each one I opened the free-play version of the same 13 games, found the RTP in the rules or help screen and screenshotted it. I went back to Starburst at Slots Temple on 4 October.
That’s 141 readings from 143 possible game-and-casino combinations, the two gaps being Fluffy Favourites at Betfred and Sky Vegas. I read the figures from the free-play versions inside real-money accounts. I’d expect the paid versions to show the same, but I haven’t confirmed that game by game. Some screens don’t show a build number, and a few games opened through bingo or help pages, as the notes explain.
The casinos were a chosen sample, not every UK operator. I included Slots Temple as a specialist site alongside the big brands. Nothing here is a recommendation: the page has no affiliate links, and the figures show what each screen said on those dates, not what anyone will win or lose. There’s more on how I work on the How We Research page.
Checking the game you’re playing
You don’t need to take my word for any of this. Open the game’s rules, help, information or How to Play menu and look for the RTP, which may be labelled theoretical RTP, average RTP or return to player. UK-licensed games have to make their rules and information about the likelihood of winning available before you play, under the Gambling Commission’s RTS 3. If the screen shows a range, treat it as a range.
The name on the reels might be familiar. The RTP setting behind it isn’t necessarily the one you’ve seen elsewhere. It’s worth knowing where to look.
Sources reviewed
I checked each recorded percentage against a dated client rules or help screenshot. For some games, I also reviewed supplier documentation and UK certification material to explain the available configurations. Links to public developer game pages provide background information; they should not be mistaken for the separate certification reports that establish particular RTP settings. UK regulatory points use the Gambling Commission’s published technical standards.
Slotathon observations
Client displays without complete RTP-tier documentation
Play’n GO
Pragmatic Play and certification
NetEnt and historic documentation
Gambling Commission
Safer gambling support
Slotathon explains how games work and what their published information means. These observations are not recommendations to gamble or predictions of individual results. If gambling is causing concern, visit the Safer Gambling Support page for UK information and support.