Slot RTP versions explained

Slot RTP versions explained: one game, several settings

When a studio builds a slot, it often creates more than one maths model for it. Each model produces a different long-run return to player, typically a step or two apart. The studio publishes the top or default figure in its marketing, and casinos pick the version they want from the list the studio offers.

To a player, the versions look the same. The symbols, paytable layout, free spins rules and animations don’t change. What changes is how often things land, so the average return per pound staked is lower on the lower settings. That is why two people can play the ‘same’ slot at different casinos and, over a long period, pay different amounts for it. Our glossary entry on RTP range gives the short definition.

Real examples of slots with several RTP versions

These figures are the versions published for each game. The casino you use may run any of them.

The pattern is common across many large studios: a top version and one or more lower ones about a point apart. Reviews of Bigger Bass Bonanza, The Dog House Megaways and Fluffy Favourites cover each game’s features in full.

What actually changes between RTP versions

A slot’s return is built from the probability of every outcome multiplied by its payout. To lower the RTP without changing the paytable, a studio adjusts probabilities: for example, slightly fewer premium symbols or scatters on the reel strips, or slightly different weightings inside the feature. Each change is tiny, but together they shave a point or two off the long-run return.

In practice, that can mean features land a little less often, or pay a little less on average when they do. You would never notice it in one session, because normal ups and downs are far bigger than the difference. It only shows up across many thousands of spins, which is exactly why players don’t spot it without checking. The building blocks are explained in how slot maths models work.

Lower versions are not rigged or unfair. Each version is tested and certified, and the figure shown in the game is accurate. It is simply a more expensive version of the same entertainment.

What a lower RTP version costs in pounds

The difference is easiest to see as an average cost per amount staked. The table compares a 96.5% version with a 94.5% version of the same game.

Total staked builds up faster than people expect. A session of 500 spins at 20p is £100 staked; a month of weekly sessions like that is £400. At that level, the lower version costs about £8 more a month on average for no difference in what you see on screen. That gap is the house edge getting bigger, and it applies to every spin.

Why casinos choose different RTP versions

Casinos weigh up the cost of running a game against their margins, the promotions they fund, and how they want their lobby to compare with rivals. A site with generous offers may run lower versions on some games; another may advertise high-RTP settings as a selling point. The choice can vary game by game within one lobby.

The same game can therefore show 96.5% at one site and 94.5% at another. There is more on this in why a slot’s RTP differs between casinos, and site-specific pages such as Coral slots RTP explain where to check figures at one casino.

How to see which RTP version a casino runs

1. Open the slot at the casino you plan to use (demo mode works too, after age verification).
2. Tap the menu, ‘i’ or question mark icon to open the game rules or help screen.
3. Look for ‘theoretical RTP’, ‘return to player’ or ‘expected return’, usually near the bottom.
4. Compare it with the versions in the table above, or with the studio’s published figure.
5. If the game lists more than one figure, check whether it depends on stake, mode or jackpot contribution.
6. Repeat the check at another site if you want the higher version; the game will look the same.

What UK rules say about RTP versions

Two Gambling Commission technical standards are relevant. RTS 3C requires information on the likelihood of winning, including the RTP percentage or house edge, to be easily available before you commit to play; for slots, this is the average theoretical return in the help screen. RTS 7D says a game’s rules, payouts and probabilities may not be changed while it is available for gambling, except as its rules describe.

The guidance explains that changes to a game’s paytable or probabilities should be made with the game offline, and the altered game should show a notice such as ‘new odds’ or ‘different payouts’. So a casino can’t quietly switch a game to a lower version mid-session or at certain times of day. That particular worry is covered in slots and time of day myths.

Slots whose RTP changes with stake, mode or jackpot

Separate from casino-chosen versions, some games have an RTP that varies inside the game itself. These are always set out in the rules:

• Stake-linked games. Mega Joker lists up to 99% only at the top stake with its Supermeter mode; Reels of Gold lists up to 96%, varying with stake; Rainbow Riches Pick n Mix lists about 94%–96%, varying with stake.
• Mode or level choices. Holy Diver lists 96.39%–96.54% depending on the level chosen; Hellcatraz quotes 96.46% for its Mixed Mode.
• Jackpot-inclusive figures. Progressive games often quote an RTP that includes contributions to the pot, such as Mega Fortune at about 96%–96.6% including jackpots. Most sessions return less than that, because the jackpot share is paid out rarely.

Watch for the words ‘up to’. An ‘up to 96%’ figure may only apply at the highest stake or best mode, so a low-stake session could be on a lower return.

Does the RTP version really matter?

If you play the same few games regularly, choosing the higher version is one of the few genuine ways to lower the cost of your hobby. It won’t make you a winner, but it means paying less for the same entertainment. Our list of best payout slots highlights games with high published figures.

Check the version before using welcome spins

PlayOJO gives new UK customers (excluding Northern Ireland) 80 free spins on Big Bass Bonanza, published RTP 96.71%, at 10p each after a first deposit of £10, with no wagering. Ladbrokes gives up to 500 free spins, 50 a day for 10 days at 10p each on selected games, after you deposit and spend £10 on slots, with no wagering. In both cases, the help screen shows the version running. 18+, new customers, terms apply.

18+. Gambling should be entertainment that costs money, not a way to make it. Set a deposit limit before you play: how to set limits. Free, confidential help: National Gambling Helpline 0808 8020 133.