What is RTP in slots? Return to player explained

What is RTP in slots? Return to player (RTP) is the share of all money staked on a slot that the game is designed to pay back as winnings over a very large number of spins, shown as a percentage. It is a long-run average built into the game's maths, not a prediction of what will happen in your session.

Updated 15 September 2026: rewritten with sourced sections on house edge, testing, RTP versions and checking your casino's figure.

What is RTP in slots?

The UK Gambling Commission's player guide to return to player uses RTP to mean the prize money a machine returns, measured as a percentage of what players put in. Because it is an average, one play can land far from it. Machines are generally measured over a long run, the guide says: 10,000 or 100,000 games is typical for compensated machines, while random machines usually need more, with the number set by machine category.

Take a slot with 96% RTP. Across all players and a huge volume of spins, the game is designed to return €96 for every €100 staked, with €4 kept by the house. That €4 is spread across everyone, so one player can finish well ahead while another loses the lot.

Turnover matters more than your starting balance. If you deposit €100 and stake €1 a spin, winnings are usually re-staked, so 500 spins means €500 of turnover. At 96% RTP, the theoretical cost of that play is €20, which is 4% of €500.

Even heavy play drifts from the design figure. In guidance for operators, the Commission gives an example of a game designed at 91.68% RTP that returned 90.42% after a month with £1.2 million of turnover. The more play that is measured, the guidance says, the tighter the acceptable gap between actual and designed RTP becomes.

How is RTP different from house edge?

House edge is the other side of the same number. The Commission's player guide describes roulette and blackjack as bankers' games built to favour the casino, and uses house edge for the average percentage of each bet the casino expects to retain with ordinary play. For a slot, house edge equals 100% minus RTP, so a 96% RTP slot has a 4% house edge.

For comparison, a single-zero European roulette wheel has 37 pockets, which gives a house edge of 1/37, or 2.70%, according to Wizard of Odds' roulette analysis. That equals an RTP of 97.3%, so on paper a 96% slot has a bigger edge. American double-zero roulette carries 5.26% on nearly all bets.

Why do short sessions not match RTP?

RTP does not show how returns are spread. In the Commission's operator guidance, volatility is expressed as a standard deviation and is used to set how wide the acceptable range around a game's theoretical RTP should be. Hit frequency shows how often spins land a win, and GLI's standard lists it beside theoretical RTP on a game's PAR sheet.

In the Commission's example, a game with a volatility of 5.6 can sit about 4.9 percentage points either side of its design RTP after 50,000 games, and about 1.1 points after 1,000,000 games, and stay within tolerance. Our guide to slot volatility and variance explains how volatility ratings work.

How is a slot's RTP set and tested?

The provider sets RTP when it builds the game's maths model. The Commission's testing strategy explains that a game's underlying maths, including its pay tables, how symbols are distributed and how features work, is what produces its RTP.

In Great Britain, games are tested by test houses on the Commission's approved list. A test house examines the game's design, from its underlying maths to the on-screen rules and theoretical RTP, and its report records each game's name and RTP. The Commission must hold that report before the game goes live, and it also expects licensees to compare the RTP a game actually returns with the figure they advertise.

Under RTS 3 of the Remote Gambling and Software Technical Standards, operators must make information that would reasonably help players judge their chances of winning easy to find before they bet. The guidance lists average theoretical RTP, house edge and the odds of each winning outcome as acceptable, and for peer-to-peer games shaped by skill or other players' actions it allows a description of how the game works and how winners are decided instead.

Can casinos change a slot's RTP?

Some providers offer several RTP versions of the same game. Hacksaw Gaming's Wanted Dead or a Wild page lists four: 96.38%, 94.55%, 92.33% and 88.42%. Push Gaming's Razor Shark Jackpots page lists 96.38% and 94.30%, and notes that the figure can differ from one casino to another.

The gap adds up over time. On €500 of turnover, the theoretical cost is about €18.10 at 96.38% and €57.90 at 88.42%.

In Great Britain, a licensed casino cannot quietly rewrite a game's maths: a change to pay tables or game rules is a major update that needs retesting by an approved test house. What varies is which approved version a casino offers, which is why the same slot can show different RTP figures at different sites.

How do you check which RTP version a casino runs?

Open the game at the casino and look in the info, help or paytable screen for the theoretical RTP. Push Gaming's Razor Shark Jackpots page, for example, points players to the user panel or the screen shown while the game loads. Then compare it with the list on the provider's own page to see which version you are playing.

First, open the free demo on our slot games page to find the info panel. Then check the paytable again in the real-money version.

How does RTP work on jackpot slots and bonus buys?

Jackpots and paid features complicate the headline figure. GLI-19, the interactive gaming standard from test lab Gaming Laboratories International, sets a minimum theoretical payout for house-banked games, and jackpots that sit outside a game do not count towards it unless the game needs them to work. If a game shows its RTP, GLI-19 also requires it to spell out how much of that figure comes from jackpots and other bonus features.

Paid features are covered too. Unless a game tells you otherwise, GLI-19 means its displayed RTP already takes into account the extra money you pay to enter a bonus round. The provider pages checked for this guide list no separate bonus-buy RTP, so read the game rules before paying for a feature.

What RTP means for your play

RTP is a comparison tool, not a forecast. It helps you compare games, or versions of one game, by showing the theoretical cost per unit staked. The Commission has said a single player's results are not a valid way to measure RTP, so it will not tell you how a session will end.

Set a money and time limit before you start, and treat the house edge as the price of entertainment rather than a loss to win back. If play stops feeling like fun, the responsible gambling page lists tools and support.

Questions about RTP in slots

What is a good RTP in slots?

A higher RTP means a smaller theoretical house edge, so a 96% version costs less per euro staked over time than a 94% or 88% version of the same game. Where a slot comes in several versions, the highest offered is better value, though it says nothing about one session.

Can a casino lower a slot's RTP?

A casino can run a lower-RTP version where the provider supplies one, which is why figures differ between sites. In Great Britain it cannot secretly change the game's maths, because that kind of change needs retesting by an approved test house; rules elsewhere depend on the licensing regulator.

Does RTP reset after a big win?

Not for online games in Great Britain, where the Commission's RTS 7A does not allow adaptive (compensated) games. GLI-19, a lab standard, points the same way, treating each game's chance events as independent of earlier ones unless its rules provide for a link, so a big win should not make the next spins tighter. Compensated gaming machines are different: in the Commission's player guide, their chance of paying out is steered by what earlier games returned, though each result is still random.

Is RTP the same as the chance of winning?

No. RTP measures how much of the total amount staked comes back over time, while hit frequency measures how often spins land a win. A slot that wins on few spins can still return a high share of stakes if its individual wins are larger.

Source information checked on 15 September 2026. Providers can add or withdraw RTP versions, so confirm the figure in the game at your casino.