book of 99 slot
Book of 99 from Relax Gaming, offering an RTP of 99%

Playing slots should be fun, done responsibly and within your budget, not as a means to make money. If you have a fundamental understanding of how slots work, then you likely also know that the house has the upper hand. Of course, on a good day you might walk away as the victor. But in the long run, the casino WILL win. RTP, which is short for Return To Player, is the mechanism that makes sure the casino will make long term profit, and RTP is exactly what we’re going to take a closer look at in this article.

Slots may be all about luck, but basic knowledge of slot machines can still come in handy. There are a large number of casino games of varying quality available on the market. Most of them are fair in the sense that they’re certified, audited by third party testing agencies, and properly licensed. With that said, there are always going to be bad apples. Luckily, we are here to try and help you identify those bad apples so you can stay away from all the pitfalls.

There is no single measurement that tells you the odds of winning whilst playing slots. Instead, there are many factors at play such as hit frequency (the probability of winning on any given spin), bonus frequency (the probability of landing a bonus), max win probability, and variance/volatility. All that the RTP tells you is how much money the machine is going to return to the players in the long run and how much the operator will get to keep. Since the stated RTP is based on millions, probably even billions of spins in some cases, it isn’t very helpful for players. More on that further below.

Can you as a player somehow influence the RTP? Not directly, but there are ways to increase your chances of coming out on top. The most effective way is to play with deposit bonuses. This extends the play time without requiring you to investing more of your own money while also allowing for more aggressive betting strategies. It’s no secret that bonuses gives players an edge over the casinos, hence why bonus abuse has become a big problem in the industry. If you want to get a better understanding of the technical aspects of the slots you play, we advise you to read our reviews.

Let’s look more closely at what Return to Player (RTP) is

The higher the Return to Player, the more money the slot is programmed to give back to the players. The numbers don’t say much about your individual sessions however. If you play at a casino like Videoslots, for example, where your individual RTP of all the games you play is displayed and saved for future reference, it can be all over the place – it can be 10% or it can be 130%. That’s not to say that lower RTP doesn’t have a direct impact on the games – it does. It may manifest itself as taking longer to trigger bonuses or experience more dead spins.

To make things a bit more complicated, high RTP doesn’t necessarily mean you’re more likely to land a massive win. Usually when speaking of potential, there is another mathematical indicator at play known as variance, or volatility, as it’s also called. Volatility decides how significant the swings are – a slot with high variance is designed to work a bit like a lottery – it will give back A LOT to FEWER players. A low variance slot works in the other way – it pays out smaller wins more frequently.

Normally, the RTP shouldn’t really be a factor to consider when choosing what online slot to play, unless the RTP is exceptionally low. We would advise against playing online slots with an RTP lower than 95%. However, due to the casino industry having become more regulated, many casinos have been forced to lower the RTP to make up for lost revenue.

Practical examples of Return to Player (RTP)

rtp slots
Starburst – RTP displayed in the paytable

To help you understand how RTP works, let’s assume that our slot machine has a RTP of 100%. In practice, this means that the casino would break even on the machine. After a year of operation, the slot would basically give back all the money wagered to the players, but each individual player may have a vastly different experience when compared to another player. Will it give all YOUR money back? Most likely not. That’s important to remember. If you’re lucky, the slot machine could give back your money AND someone else’s too. As we said before, the RTP doesn’t mean much over 1 or even 50 individual sessions. Your individual RTP can end up being 140% after you’re done playing for the day. Play enough spins, however, and this number WILL eventually even out.

As a standard, most reputable casinos offer games with the RTP set somewhere between 94%-97% (96% is the most common). This ensures that they will make profit, something that is, of course, necessary to survive as an operator. The RTP of any given slot should be stated in the help file, or in the info text of the slot, although there are some exceptions to this. Games licensed in Curacao, for example, won’t always disclose the RTP. Always aim for playing slots with the highest RTP.

Variance & volatility

Variance is the spice that makes slots interesting to play. If variance works in your favor, you can hit a massive win on your very first spin and walk away with a huge profit. On a day like this, the casino might actually end up in the red. In fact, there have been examples of casinos having to close due to players having landed extreme wins that the operator had failed to protect themselves from. Most of the time, however, all the casino owner has to do is to sit back and wait as for the RTP to even out.

Games to avoid

To be on the safe side, you should stick to properly licensed casinos regulated by reputable governing bodies such as the Malta Gaming Authority, the UK Gambling Commission, and the Swedish Gambling Authority. This ensures that you’re playing at a fair, transparent and compliant casino. Playing at off-shore casinos (most commonly Curacao) is usually a bad idea and many times you won’t even be able to tell what the RTP of the game is.

While most providers ship their games with a fixed RTP, some allow for casinos to choose between a set number of RTP settings in order to adjust for particular markets. This can be necessary if, for example, a specific market involves high taxes, in which case the casino might need more headroom. It’s also possible, of course, for a casino to choose a lower setting out of pure greed.

Novomatic, Play’n GO, Pragmatic Play, NetEnt, and Red Tiger are just a few of the established providers that allow casinos to choose from a predefined range of RTP settings.

And finally…

  • Jackpot slots typically offer lower than standard RTP since each spin contributes to the jackpot.
  • Variance has a much bigger impact on your individual sessions than a 1-2% difference in RTP. Nonetheless, you should always aim to play at casinos with the highest RTP settings.
  • Physical slot machines in land-based casinos are designed to offer much lower RTP than its online counterparts. The reason for this is that land-based casinos have much larger expenses. The RTP of a physical slot machine may be as low as 84%, or even less. This should be avoided at all cost. Read more on why you should avoid playing at land-based casinos.
  • Casino bonuses increase the expected value (known as EV+), but only if you play with quality bonuses such as those listed on our best casino bonus page.