Every slot machine or online slot game is set up to pay a little less than it takes in from the player, and in case of online slots it is a precise number that is expressed as Return to Player (RTP) percentage. The number is always a bit less than 100.00% as the game pays out less than it gets from the player, and this is the formula:
RTP = (total amount returned to players) / (total amount bet by players)
If a player would wager $1000 and the slot game would pay out $950, the RTP would be 95.00% and the house edge would be the inverse of that, 5.00%.
Online slots depend on their software random-number generator and the setup of the game, so exact RTP can be determined. Some online slots developers choose to publish their RTP percentages while others do not. Playtech, NetEnt and Betsoft tend to publish RTP for their games, while Realtime Gaming (RTG) avoid it at all costs.
Slot game payout rate is calculated to cover all the aspects of the slot game, including bonus games, free spins, jackpots, even progressive jackpots. That means that a high-RTP game which has a big jackpot or a progressive jackpot certainly has that jackpot included in the calculation. Meaning, over several years of play a jackpot will be awarded to someone and that will bring the RTP up to, say, 96.30%, but if we’d exclude the jackpot from the equasion the slot game would pay out very little during normal play, probably around 85% or even less than that. In other words, someone would have to win the jackpot to balance the game, and even then the house would still get the edge.
As opposed to big jackpot games, slot games with a high payout but very poor jackpot or no jackpot at all are almost certainly rewarding during normal play. Some games even have different RTP numbers for various stages of the slot game, and also for various bet sizes. One notable example is Goblin’s Cave which has RTP 99.32% but only if max bet is used. When a smaller bet is used, the RTP goes down to 94.3%.
Misconceptions about RTP
The most common misconception about how slots work is that they have to even out in the long run and that after a cold streak a hot one will follow as the slot game has to pay out in order to keep the payout percentage as described. But it does not work that way. Every single spin on an online slot still has the exact same probability of outcomes as the previous one, as the previous spin does not affect the probability of the next one.
This is why the Return to Player (RTP) percentages are more precisely known as theoretical percentages. They won’t be seen in reality, or they probably eventually would, but only after many many years or even centuries of playing. The numbers are theoretical because the probabilities of each outcome (e.g. small win, big win, jackpot) are added up and we come up with a theoretical payout percentage if these probabilities would be exactly what had happened on that particular slot game in that exact number of spins.
For example, imagine a slot game which rewards you with $1 win 50% of the time, $2 win 10% of the time, $10 win 1% of the time, and a $500 jackpot 0.01% of the time.
In order to calculate the payout percentage for that slot, we need at least 100 / 0.01 = 10,000 spins (that’s how many we need to incorporate jackpot into our equasion). In those 10,000 spins this is what will happen, in theory, according to the hard-coded probability percentages:
1 jackpot x $1000 = $1000
$10 x 100 = $1000
$2 x 1000 = $2000
$1 x 5000 = $5000
When all that is summed up, the slot game would pay out $9000 while taking $10000 from the player for a 90.00% theoretical RTP. But this doesn’t mean you’d get exactly $9000 if you played exactly 10,000 spins on this slot game. Your results would vary wildly.
Also, we couldn’t say it’s a misconception but is actually a case of not even considering one important aspect. The game isn’t set up to pay out 95% to a single player, but to pay out 95% to all the players in the wide world. You’re not the only one playing, there could be thousands of players who are playing that game online at the same time. All are playing according to the same rules and the same probability percentages which are hard-coded into the game. So it would be ridiculous to track only your own results – you’d have to track all the players if you wanted to see what’s really going on. In the time between your two spins there could be a hundred players who did a spin themselves, so how can you say you’re in a streak of any kind? The game doesn’t care who won the bonus game. But even if you could track all spins, you couldn’t make sense of them as each new spin will still be random and won’t depend on the result of the previous one(s).
Is jackpot due?
A common misconception is that a slot game with a large jackpot that’s been piling up for a long time is ‘due’ to pay out some time soon. This is not the case. The very different periods of time between two jackpot payouts are due to the very, very small chance of it happening. But the chance is still the same on every spin regardless of the size of jackpot or the length of time since the last jackpot.
This misconception stems from the pre-online casino play when RTP percentages weren’t publicly stated and various casinos had slot machines rigged in different ways. In case of online slots, special attention is given to their setup, and only the fair ones can be licenced. In those slots, there is no change of chance of a jackpot depending on the time elapsed since the last win. That’s a hard fact.
How to make the best of it
Ideally, a player looking to make some money on slots would avoid the progressive jackpot slot games, slots with a big jackpot, and slots with very rich top win in general – as all these are sign that you have to win some of that in order to balance the game and bring it up to it published RTP. If a player wants a short-term game that’s as fair as possible, he/she will choose a high-RTP slot that doesn’t have high winnings, as that means the slot game is giving lots of small wins.
Is variance important?
Variance is how often does a slot pay out. A low-variance slot game will pay out often and will keep rewarding you with small wins, while with a high-variance slot game you’ll have to wait a while before you get a bigger win. It’s down to personal preference, but it’s important to have some slot playing skills (or read good slot reviews!) in order to choose the slot game that best suits you.
We did the reviews for UK, EU and most worldwide players and provided our readers with a list of top-paying slots, and the one with highest RTP isn’t the best to play. There are many details that make all the difference, but RTP is a very good general overview of how greedy the software developer and the casino are. The bigger RTP, the better game, that’s for sure.