A Guide to RTP Slots – What is RTP and how does it work?

Updated: 31 Oct 2023

When you first discover online slots you’ll no doubt be amazed at the enormous range of games you can find. The best slot sites have hundreds, sometimes thousands, of imaginative slots waiting to be played. The artwork alone creates an absorbing arena where you can travel through time, visit remote landscapes or explore scary crypts you’d never dare to enter in real life.

But then, many newcomers wonder if, beneath the colourful images, every game must indeed play the same. Yet they couldn’t be more wrong. Technologically advanced mechanisms and a host of unique features add to the variety within every game and amazing new slots are constantly being developed. Whether you choose paid or free slots, the RTP percentage is one of the most influential factors. It doesn’t exist in any physical or electronic form, but its effect can greatly impact every slot game adventure.

In This Guide


RTP stands for Return To Player. It’s derived from a series of mathematical calculations and is always presented as a percentage. Every slot game has an RTP rating, which basically indicates how much you expect to receive back from your spin. The RTP of a slot game is comparable to the betting odds that you’ll come across in horse racing. No one ever expects those odds to be entirely accurate. Similarly, RTP is an estimate of how successful your wager or spin might be.


The average RTP of a slot game is around 95% to 96%. In theory, it means that if random chance or luck conformed exactly to the laws of probability, you might receive back that amount from your bet. For example, if your bet was £100, you could theoretically win back £95 or £96. But as we know, luck is entirely unpredictable.

A simple experiment can easily demonstrate the effect of chance on a slot’s RTP. If you toss a coin twenty times, you’ll notice the results are far from evenly distributed. There’ll be sequences where heads have landed several times in a row or tails appears only at the beginning. Repeat the coin toss another twenty times, and the results are still haphazard. But if the coin is tossed perhaps a million times, the results across all the tosses should evolve into a more balanced picture.

In the same way, only a few spins on a slot game will provide inconsistent results due to luck’s unpredictable nature. RTP refers to several, perhaps a million or more spins performed over an indeterminate time. It’s only then that luck’s influence over the results begins to look more balanced. Even the most dedicated slot games players are unlikely to spin the reels that many times in a row, so their results while playing are inevitably going to arrive in a random order. But theoretically, a slot’s RTP reflects the results it could eventually achieve.


As we’ve seen, RTP is based on the theoretical outcome of millions of spins. But there is also a practical, mathematical equation that determines the percentages. The formula takes the collective amount of money the players receive back and then divides that figure by the total sum of money that was originally wagered. The answer is a mathematical average that provides the RTP’s percentage.


As part of the licensing regulations, the RTP of individual slot games should be available for players to view. On the screen display of a slot, you’ll see a small info button that reveals the paytable and the RTP when clicked. Occasionally, you might find the RTP of a slot isn’t always exactly the same at different casinos. This is because some games are issued with a slightly variable RTP that the slot sites can adjust. The fluctuation enables the casinos to increase or decrease the House Edge or the portion of your bet it retains. These funds are used to meet the casino’s overhead.


Apart from providing slot sites with funds, a small proportion of bets from certain games contribute towards progressive jackpots. If casinos couldn’t retain the part of your bet known as the House Edge, exciting slots such as Microgaming’s Mega Moolah wouldn’t be able to provide such amazing mega-sized cash prizes. Generally, the role of RTP is to provide players with an estimate of how profitable a game might be. This is particularly helpful with new slots that have just been launched and are not yet reviewed. If a slot is listed with a 98% RTP, you might assume there could be plenty of cash prizes in store, but several factors can affect its performance, including luck, free spins bonuses, the size of your bet and volatility.

It’s this variation in RTP performance that adds such excitement to every online slot game. After all, if slots always provided results that corresponded to their RTP percentages, they would be so predictable that they might appear slightly dull. Slot games are meant to have an atmosphere of suspense and excitement, providing every spin of any game with the opportunity of landing a thrilling cash prize or unlocking an entertaining bonus feature.

You can’t assume either that RTP percentages will spin out larger cash rewards simply because their ratings are higher. Slots with lower 95% RTP percentages can often be highly lucrative performers. Cleopatra by IGT is a prime example. It’s an easy-to-play, five-by-three that’s filled with Ancient Egyptian symbols, but fifteen free spins in the bonus round are loaded with triple multipliers.

Best of all, the bonus can reactivate time and again to provide up to 180 free spins. It’s one reason why Cleopatra has been a firm favourite since its launch in 2005. Learn How to Play Cleopatra Online Slot. It’s best to take the RTP as a guide but then look forward to the thrill of never knowing which slot game spin could contain an exciting cash prize.


If you decide to play at one of the best slot sites, such as those we feature in our listings, you’ll discover thousands of exciting slot games. With such a great choice of themes and RTP ratings, it can be hard to know where to start. We’d suggest trying out some free slots or following these helpful steps:


This is important as it sets the tone and atmosphere of your entire gameplay. For relaxation, look for a fantasy-style slot or a festive tale of Irish Luck. A theme of mystery and intrigue is sure to provide plenty of escapist fun, so try Tome of Madness, a Rich Wilde adventure from Play’n GO. It has a 96.59% RTP and loads of features, including special wilds. Read Play’n GO’s Rich Wilde Slots: A Complete Run Down.

A fast-paced, brightly coloured adventure such as Reactoonz 2 will find you playing adorable monsters in fun, entertaining and exciting surroundings. Its 7 x 7 grid format is fast-paced and its avalanche reels with cluster pay mechanics keep you gripped. With an RTP of 96.10% this is a high volatile slot.

Play Reactoonz  (RTP: 96.10%)


Using the RTP percentages as a guideline, you can understand how much prize-winning action the game might provide. High RTP percentages like the examples we include in the next section, are always popular. There’s also plenty of fun with slots with lower RTP ratings.


The volatility of a slot usually affects the size and frequency of your cash prizes. Low variance generally provides small prizes regularly. One of the best slots with low volatility is Starburst from NetEnt. It’s a five-by-three, easy-to-play game with an exciting re-spin feature and a 96.10% RTP.

Play Starburst – Choose from our free spin bonuses!

High variance slots usually bring potentially huge cash prizes, but you sometimes have to be patient for them to arrive. Dead or Alive 2, a Wild West thriller from NetEnt is highly volatile, with an RTP of 96.80%.

Play Dead or Alive 2 Free (RTP: 96.80%)

You can choose to play any of the three free spins bonuses.


The number of ways to win has taken on a new significance since Big Time Gaming launched the amazing Megaways format in 2016. There are up to 117,649 ways to win on slots such as NetEnt’s Twin Spin Megaways which has a 96.04% RTP. It has the classic fruit theme and includes a free spins round.

Play Twin Spin Megaways (RTP: 96.04%)

Many games feature a 243 ways to win mechanism, which helps to increase your prize-winning potential. Game of Thrones from Microgaming has a low 94.86% RTP, but four exciting free spins bonus rounds offset it. Disco Diamonds from Play’n Go is an exciting Saturday Night Fever-inspired game. It uses the same 243 ways to win format, has a 96.29% RTP and free spins galore.

Play Disco Diamonds Free (RTP: 96.29%)


For an uncomplicated set up you can always rely on an easy to play, three reel classic slot such as Bar Bar Black Sheep from Microgaming with a 95.00% RTP. You can also have the fun of testing out the five reel version where there’s a 95.32% RTP. If you’d like to try more reels, a slot that’s sure to please is Pirate Gold Deluxe. Full of pirates and treasure, it’s a five reeler with 40 paylines, the chance to win 1000x your bet and a 96.48% RTP.

Play Pirate Gold Deluxe Free (RTP: 96.48%)
While Cascading Reels are a thrilling addition to a slot, another exciting reel formation is the cluster pays mechanism. The winning formations appear as clusters through the symbols sitting on adjacent spaces. They then disappear to be replaced by new symbols. Gems Bonanza from Pragmatic Play is a good example of this. It’s great fun to play and has a eight by eight grid along with a 96.51% RTP.

Play Gems Bonanza Free (RTP: 96.51%)


Every software developer has a distinctive style. Microgaming has a great variety of slots from straightforward, easy to play games to complex formats such as the ever popular vampire tale, Immortal Romance. It comes with a 96.86% RTP and four exciting free spins bonuses you reach by progressing through different levels. NetEnt slots often feature intricate artwork and detailed storylines. One of the best examples is the legendary Gonzo’s Quest with a 96.00% RTP. It’s based on a real-life Spanish Conquistador and introduced the rewarding cascading reels format that can provide multiple wins from just one spin. Other talented developers include iSoftbet, Quickspin, Foxium and many more. You’ll soon find out your favourites once you’ve played a few slots from each developer.


There’s no secret formula that might reveal which are the best RTP slots. With so many exciting themes, formats and varied RTP percentages, we’re literally spoilt for choice. But you can be sure there’s a high-quality slot game to suit every mood and taste. Here are some of our current recommendations for entertaining slots with the highest RTP ratings:



This classic fruit is easy to play and comes with the added excitement of a progressive jackpot. The five by three reels include apples, oranges, gold bars and Lucky Red Sevens. Land a row of bells to enter the lucrative Bell Mode and fill the meter with gold bars to win a multiplier worth twenty-five times your bet.

Play Ring the Bells at: CasiGo Casino


Discover a dreamy underwater kingdom where there are forty fixed paylines and a five by four playing grid with lots of jellyfish, turtles and valuable gems. It includes a generous pays both ways format, colossal mega-symbols that cover up to four spaces, exciting re-spins and a free spins bonus. There’s even a nudge feature to help you fish for some amazing payouts.

Play Secrets of Atlantis at: Diamond 7 Casino


The creators of Megaways have added even more excitement with this adventurous five by three slot with expanding reels that add up to 248,382 ways to win! Cute Alice in Wonderland style graphics highlight a cosy woodland with teapots and sleepy dormice. But land yourself three white rabbits and you’ll receive fifteen free spins in the lucrative bonus round.


This is one of the easiest classic fruits to play, but it’s also highly rewarding. It has a three by three grid packed with colourful Lucky Sevens, cherries and bars. There’s only one payline, but there are multipliers on offer worth five times and twenty-five times your bet! Read more about the Best Microgaming Payout Slots

Play Couch Potato at: Mr Slot


Another exciting fruit classic, but this time there’s a five by three grid with thirty paylines. Land a selection of juicy cherries, Lucky Red Sevens, bells and a gigantic sparkling ruby to unleash a variety of free spins, stacked wilds and a generous Wheel of Fortune bonus.


You’ll love the detailed graphics of this stylish five by three slot featuring elephants, pandas and tigers living in a beautiful jungle. There are 243 ways to win and there’s an exciting re-spin feature that you can also purchase. The bonus round has fifteen free spins with a triple multiplier and it can be reactivated for even greater cash prizes.

Play Wild Orient at: Trada Casino



Barcrest has an entire series based on the entertaining theme of Irish Luck. This version from 2016 has five reels filled with good luck charms and magic toadstools along with twenty paylines. It’s packed with features including three wheels of fortune, thirty free spins and a choice of five amazing bonus games.

Play Rainbow Riches at Play OJO Casino


This amusing horror features a variety of vampires including the creepy, but bald Nosferatu. Its five by three grid had twenty paylines and the reels are packed with an armoury of wooden stakes, Crucifixes and garlic. There’s even ten free spins and an eerie Pick Me bonus with coffins.

Play Blood Suckers at Hello Casino


You’ll love this energetic fruit classic that was released in 2016. There’s a high variance that might help you land some mega-sized wins. It’s five by three with ten paylines, but the joker only lands on the central reels. There’s a mystery prize when landing a trio of jokers. And in Jokerizer mode you have the chance to gamble for more prizes or keep your cash.

Play Jokerizer at Rizk Casino


Cat people everywhere will appreciate this action-packed five-by-three thriller filled with domineering felines posing as gangland bosses. But the ginger tom and his rivals bring some amazing rewards to the nine paylines, including reels of stacked wild kittens and ten free spins with a lucrative quadrupled multiplier.


Underwater themes are always popular and this five by three has plenty of charm with antique-style graphics. It includes turtles, mermaids and lobsters, twenty-five paylines, expanding wilds and up to fifty free spins. With a low variance, you shouldn’t wait long before landing exciting cash prizes.



This three-by-three classic fruit is excellent fun to play. A mad joker is hiding out with the cherries and plums, but if you land a row of three, there’s a top cash payout of 2,000 times your bet. After any win, you’re eligible for a mystery, random prize in the Supermeter at the top of the reels. And as if that’s not enough, you might even win the progressive jackpot on offer.


This exciting five-by-three slot with ten paylines is dripping with mad symbols, such as Dracula wearing his shades, his spooky castle and a strange rabbit! You can get your teeth into the Heart Attack and Super Graveyard Bonus rounds, with up to fifteen free spins and the chance to win loads of cash prizes.

Play Ooh, Aah, Dracula at Playzee Casino


Exploring the jungle has never been such an incredible experience! This colourful slot with lush scenery was launched in 2013. It’s a bit complicated, but it’s got one of the highest RTP ratings ever and a highly original playing grid with two sets of five rows. At the start of each spin, you can choose a special symbol that will appear on each mini reel.

Play Ugga Bugga at Slots Heaven Casino