What is RTP (Return to Player) and How is it Calculated?

Understanding RTP, or Return to Player, is essential for anyone venturing into the world of online gaming. This percentage offers valuable insight into the potential returns a player can expect from a game over time. In this article, we will explore the nuances of RTP to help UK gamers to make more informed choices when playing online.

What Exactly is RTP (Return to Player)?

We all know that a casino is a business - and that’s the business of making money.

Therefore, all gambling games have a ‘House Edge’, which is the amount a UK casino is likely to retain as profits over the course of punters playing their games.

The Return to Player figure is simply the inverse of this house edge. It’s the amount of money paid back to players, expressed as a percentage.

As an example, many online slots have a house edge of 5%, which means that the RTP of these games would be 95%.

The RTP % for casino games is often available in the game information tab, with some online casinos creating special categories for high RTP games within their games lobby.

What’s the Difference Between Theoretical RTP and Actual RTP?

The RTP % figures quoted by a game or provider usually refers to the theoretical RTP, which is based on the probability of an event occurring. Whereas the actual RTP is what a player actually receives over the course of a playing session.

During certification, online slots are put through rigorous testing that involves simulating play to check the Random Number Generator (RNG) is performing to expectations with a standard distribution of results.

However, the results can vary quite dramatically, particularly with a small data sample.

For example, flipping a coin offers only two outcomes of which both offer an equal chance. If you bet £1 on heads twice, the anticipated result would be one to land on heads and the other on tails, meaning you would win once and lose once. You’ll have bet £2 and received £2 back for a theoretical RTP of 100%.

In reality, it is entirely possible for you to flip two, three, four or more heads in a row.

In this example, if you were to make 5x £1 bets on heads and each bet won, your actual RTP would be 500%.

Of course, over a much larger sample size, you would expect an equal number of heads and tails, which is why a large data sample is required to gain a better representation of a game’s actual performance.

How Do Online Casinos Apply RTP to Games?

The house edge and RTP are built into every casino game - whether it’s table games, game shows, slots or scratchcards. There won’t be a single new casino game where careful consideration hasn’t gone into creating a math model that offers fair value on both sides.

If we take a traditional, mechanical slot machine as a good example, there are typically 20 symbols on each of the three reels. Each reel will only contain one Jackpot symbol, with the actual odds for all three to land on the same spin is 1/(20x20x20) = 8,000. But when it does, the machine is likely to pay you 2,000x.

So at first glance, it would appear that you will only receive a 25% RTP, but in reality there will be many other reel symbols that increase your chances of landing a winning combination. How many of them will determine the theoretical RTP.

Online slot machines work in a similar fashion, although they’re not limited by physical space on the game reels. This is how Big Time Gaming’s innovative Megaways game mechanic can offer an incredible 117,649 ways to win. Each spin creates a random number of reel symbols that are in-play, resulting in some truly epic wins.

Hailed as the biggest innovation in slots over the last 20 years, Megaways has spawned an entirely new generation of online slots and has even been applied to revive some forgotten classics.

What Percentage Do Slot Machines Payout?

The standard RTP for an online slot machine is around 95 or 96%.

Often, the best UK slots will be judged by their level of RTP and may be categorised into low, medium or high RTP. Anything below 94% should be considered low, while anything above 97% should be considered high RTP.

Relax Gaming’s Book of 99 is a fine example of a high RTP online slot with an incredible 99% RTP. Thunderkick’s 1429 Uncharted Seas offers a similarly generous 98.5% RTP, while NetEnt’s Bloodsuckers is probably the most well-known RTP slot with a 98% RTP.

Blood Suckers became an extremely popular slot for players looking to wager their bonus funds as it is low volatility, which when coupled with a high RTP results in an easy wagering with little risk. Today, it’s actually prohibited in most casino bonus terms and conditions, for that exact reason.

Progressive jackpot slots are a little different as the RTP can be split between the base game and the progressive jackpot pool. Typically, 7-10% of your stake on each spin is automatically deducted and contributed towards the jackpot pool. This will negatively affect the base game RTP somewhat, but will make a positive difference to the progressive jackpot RTP.

RTP in American Roulette

Wherever possible, you should choose to play European Roulette over American Roulette, with the reason for this coming down to RTP.

American Roulette offers a 94.74%, while European Roulette offers an increased RTP of 97.3%.

This is because American Roulette offers not just one zero on the wheel, but also a double zero too. 

Although you will receive the same payout for a win, there’s less chance of winning due to the additional number on the wheel.

RTP in European Roulette

As mentioned above, European Roulette offers an improved RTP, owing to the fact it only features one zero on its wheel.

While the additional 2.56% might not seem too significant, it really can make a difference - particularly if playing the even money bets of Red/Black, Odd/Even and High/Low - as you have the additional losing outcome on American Roulette of the double zero.

What RTP Can You Expect When Playing Blackjack Online?

Unlike the complete randomness of slots, blackjack does involve an element of skill. As an example, drawing a card when your total is 20 is likely to lose a significant amount of the time!

Basic Strategy is a universally-accepted set of rules that players can use to increase their chances of winning.

Playing by these rules, you can expect a 99.5% RTP, making it one of the highest-paying RTP games available in a casino.

It should be noted that there are many variations of blackjack with differing rules, including the opportunity to surrender, double down or split your bet.

Live Dealer Blackjack games can offer the experience of playing against a real dealer rather than a Random Number Generator (RNG).

Evolution Gaming, Stakelogic, Playtech and Pragmatic Play Live have created some of the most popular live blackjack games, including enhanced odds versions. While these may appear very generous, the underlying RTP will be lower unless you hit a multiplier.

Single Deck Blackjack and Switch Blackjack are two great examples of RNG blackjacks games, which offer an even higher RTP - as long as you play to optimal strategy.

Be warned… Making too many ‘hero’ calls or using intuition rather than odds and percentages will likely see your expected RTP to plummet.

Our Top Tips for Choosing Casino Games by RTP

• Balance RTP with Volatility - Wouldn’t it be great to sit down at a game that has a low RTP but can hit big? If you do, it’s certainly time to consider leaving as you’re on the right side of volatility, which refers to how often and how big the payouts will be. Selecting games based on your attitude to risk is essential as games with higher volatility will pay out less often. Lower volatility games can offer you more playing time with less swings, but are less likely to win big.
• Explore Game Features - While RTP can be an important factor when choosing casino games to play, it’s more than that. Finding games that keep you entertained and providing value for money is also important. The difference between a 95.6% and a 97% RTP slot is minimal, especially in the short term. So, take your time to enjoy the theme and features.
• Gamble Responsibly - It goes without saying that you should always play within your means. While RTP is a good indication of what should be returned to the player, it’s not something that can be relied upon with any confidence. Especially over the short term. If you’re facing a downswing, continue playing with the correct strategy or stop. Don’t ever deviate away from sensible playing to chase losses.

Final Thoughts

We’ve covered most things about RTP in this article and hope we’ve answered your main questions. Now you’re armed with the right information, you will be able to make smarter choices when it comes to choosing which games to play.

While RTP should be considered a great benchmark when evaluating a slot or casino game, volatility should also be taken into consideration.

Just because a game is judged to be low RTP doesn’t mean it should be avoided. A low RTP game with high volatility can reap big rewards if you get lucky. You just need to ensure you don’t hang around and continue playing for too long after!

It’s also important to understand that RTP is a calculation used to identify how much is returned to ALL players - collectively throughout the lifecycle of a game - and not just one person in a single session.

At the end of the day, unless you’re going to be playing a huge number of game rounds, the actual RTP you will achieve is very unlikely to be anywhere near that which is advertised.