Slots RTP

A slots RTP or Return To Player is a rough indication of what a game has been programmed to pay out over a very large number of spins. It’s basically the reverse of the house edge, and it’s one of the biggest factors in how much players win or lose in the long run (clue: it’s a very, very long run).

You can look at RTP as just a number that vaguely indicates how generous a game is. Or you can use it to compare slots, when you’re deciding what games to play.

Or if you’re a slots nerd like me, you could go under the hood and discover a magical world of slots software and gambling mathematics. Don’t worry, it’s more fun than it sounds. Stick with me and I’ll make a slots nerd out of you yet.

What is RTP?

When we talk about online slots or any type of game of chance, the RTP or Return To Player is how much of the money that’s wagered is returned to the players. It’s sometimes called the expected rate of return, or the payout ratio.

RTP is the opposite of the house edge. The Return To Player is what you get back, and the house edge is what the casino keeps. Rainbow Riches is one of the most famous and popular slots ever. The game’s RTP is 95%, which means the house edge is 5%.

Money Staked on Slots

Rainbow Riches should – in theory, on average, and in the long run – pay out prizes that amount to 95% of the total money it’s taken in. In the lifetime of that slot, if £50 million has been wagered, you would hope and expect £47.5 million to have been paid out.

But RTP goes a lot deeper than a simple percentage. The key words here are ‘on average’ and the ‘in the long run’. We’ll get to that in a mo.

Highest RTP Slots

Before get into the weeds of RTP and slot math, let’s check out some of our highest RTP slots.

The average slots RTP is around 96% but some go as high as 98%, others as low as 92%. Don’t forget, roulette has an RTP of 97.3% and Live Three Card Poker has a 96.63% RTP, so most slots are in the same ballpark.

Top RTP Video Slots

When it comes to RTPs, this is the Olympic podium of online slots. Except with 5 medals. With extra money back on every bet (met OJOplus yet?), you’d be hard pressed to find better value for money.

Just a quick note to remember. Some of these games have variable RTPs, with higher RTPs for ‘big bet’ modes, so it’s worth checking the game rules before you play.

Highest RTP Slots

Top RTP MegaWays Slots

These days, if you ain’t got 117,000 paylines, you’re nobody. Here are the best value games from the MegaWays camp.

Highest RTP Megaways Slots

Top RTP Jackpot Slots

These games are the cream of progressive slots. Although they tend to have slightly lower RTPs, that’s the price you pay for the chance to win big.

Highest RTP Jackpot Slots

How does RTP work?

Let’s first compare slots RTP to table games. The RTP in roulette comes from the difference between the payout odds (35 to 1 for a single number) and the true odds of a number being chosen. A single number pays 35 to 1, but without the house edge, it would be 36 to 1. That’s how RTP works in sports betting too.

In online slots, the RTP is decided by the slots provider and then programmed into the slot’s software code. RTP is just one part of an extremely complex set of rules in a slot’s software that decide how the returns should actually be returned.

Variance & the importance of The Long Run

Just because a slot has an RTP of 99%, it doesn’t mean that if I stake £1, I’ll get 99p back. The proper definition of RTP is actually the “theoretical average return to player”.

In a very small sample size of spins, luck is a massive factor, far bigger than RTP, and as a result, you can get a massive range of outcomes. In 10 spins you might get either 0% RTP (you don’t hit any wins) or 100,000% RTP (you hit the game’s 10,000x max win), or anything in between.

But the more games you play (i.e. the bigger the sample size), the closer your results will get to the actual RTP. In low volatility games like Blackjack, you may only need to play 10,000 hands to get paid out what the game is designed to return. Because slots are so volatile (the wins are so varied in size), you need to play around 100,000 spins before the randomness (i.e. variance or luck) even begins to be taken out of the equation.

Here’s the proof of that in a graph from the UK Gambling Commision that illustrates how many spins you need to play to get an accurate RTP. Even after 100,000 spins, a game can pay out 5% above or below the advertised RTP.

RTP Graph

If you really want to know if a slot is paying out what it is designed to, you need to play well over 1 million spins and even then, a game’s payouts may still deviate by one or two percent! And on jackpot slots with their extreme payout events, tens of millions of spins may still be enough to truly guarantee you get returned what the theoretical RTP says.

How do we know if a slot is sticking to its RTP?

If you want to get really nerdy about RTP, check out this article from the British gambling regulator, the UK Gambling Commission. They insist that casinos monitor their games to ensure the payouts are fair. In other words, that they’re paying out roughly according to the stated RTP, and certainly not significantly less than they’re supposed to.

This live monitoring of RTP is done by taking a big enough sample of slot spins and dividing the total won by the total wagered. This gives them the actual RTP which they can then compare to the programmed theoretical percentage.

Interestingly, they also talk about how different bonus features within a slot can have their own RTP, so it’s not always helpful to look at a game’s overall RTP. A 50/50 gamble feature may have a 95% RTP, the base game can have a 97% RTP and the progressive jackpot its own RTP, too.

If you want to go even deeper into the world of RTP, variance, standard deviation and other gambling math theory, Wikipedia has got your back. But I digress, let’s get back to slot RTPs, and how to find them.

How to find a slot’s RTP

OK, so we know that in gambling, RTP is very approximately what a game pays out over an extremely long period of time. And if you decide it’s a number worth looking at before you play a slot, luckily it’s easy enough to find.

By law in the UK, online casino games must display their RTP clearly somewhere in the game. With slots, you can usually find the RTP in the game rules or help files. As you can see with Wolf Gold, the RTP found in the game rules below the payline information, is 96%.

Wolf Gold Slot

RTP & volatility

I’m about to discuss if slots RTPs really matter, but to do so, I need to cover a few other bases. RTP is only one part of a slot’s software. The designers also have to choose how the wins are awarded; Both how often the slot pays out, and the size of the wins.

The slot is programmed with a hit rate (how often a win is awarded e.g. 1 win at slots every 3.28 spins on average) and volatility or variances (low or high variance slots). This last factor basically decides if your slot pays out infrequent big wins or regular small wins, or somewhere in between.

Low volatility slots pay out small wins very often. High volatility slots pay out very rarely, and mostly bigger wins. Most slots have medium volatility with a balance of win frequencies and sizes.

When a slot advertises its maximum multiplier, that’s one factor that goes into the volatility. The varying size of the pay outs in any 1,000 or 1 million spins is also important.

The last piece of the puzzle is the random number generator or RNG. Once the game knows how much it’s got to pay back out, and how volatile it should be, the RNG throws some randomness into the mix, just to keep us on our toes. The game will be as random as possibly within the boundaries of the rules it follows on RTP, volatility and many more.

Does the RTP really matter?

So online slots RTP tells you one piece of information about the slot; How much it’s supposed to pay out on average. It can be an important number, but it depends how much you play.

Let’s say you have a choice of 2 slots, one with an RTP of 98% and another with 96%. What difference will it really make to how much you spend?

In theory, if I wager £10,000 on both slots, I’d get £9,800 back on slot 1, and £9,600 back from slot 2. So, by choosing the higher RTP game, I save myself £200.

But the RTP doesn’t work like that, so the true answer to the question ‘does a slots RTP matter?’ is probably not much, because of the amount of luck involved. If you only ever play 10 slot spins in your life, the RTP will make no difference at all. But if you play millions of spins over your lifetime, it’s worth being more ‘price sensitive’ and favouring higher RTP games, as you may get more play for your money.

What the RTP doesn’t tell you is anything about the gambling experience. Two games of chance can both have a 97.83% RTP but very different feel to play. You could be in for a fairly gentle ride, like in Blackjack – the ultimate low volatility game – where you win and lose an equal number of games without any long runs of consecutive losses.

Or you could be hunting down a longshot (a roulette single number, a slots jackpot or even the national lottery) where you have long run of losses (or very small wins) and the occasional big win.

It’s good to care about getting the best value for money, but it’s factors like hit rate, volatility and of course the slot’s design, that have more say in your play, and determine if you’ll enjoy playing the game or not.

So hunt out the best RTP slots by all means, but don’t expect it to have a noticeable impact on your experience or bankroll. It’s probably more important to find online slots with the kind of payout model that suits your style, than focus on the slots with the highest RTP alone.

How PlayOJO boosts every slot’s RTP

I think I’ve mentioned RTP around 87 times by now, so it’s time to stop. But before you go, here’s an important return-boosting perk that we at the Fair Casino have added to all of our online slots and table games.

Because we give you money back on every slot with no strings attached, the actual return you get is better than the RTP alone, which essentially means you get the UK’s best RTP slots. Here’s one example we give about the difference between playing slots here and at another (less fair and generous) casino.

A slot with an RTP of 96.4% could actually return something like 97%, once you factor in the OJOplus cashback. But the good thing about OJOplus is that there’s zero variance. You won’t have to wait 1 million spins to get the correct return. You get your OJOplus return after every spin, without fail. That’s fair gaming for ya!

Thanks for been patience with me as I’ve taken you down my RTP rabbit hole and shared my love of gambling math. I hope you’ve picked up something useful about how online slots pay out.

Now it’s your turn to have fun and play safe!

Daniel Grant

Daniel Grant

Dan Grant has been writing about gambling for 15 years, and been fascinated by beating the odds for even longer. Now he’s on a mission to help others bet smarter and avoid the mistakes he made. When he’s not obsessing over bankroll strategy or counting cards badly, he’s hosting The OJO Show podcast.