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Last Updated: May 26, 2026
Do Slot RTP’s Actually Match what Casinos Claim? We ran the numbers
Written by Iain Fenton
To find out, we ran 10,000 spins across 20 popular slots to compare advertised RTP versus actual results. We placed stakes of £0.20 per spin with 500 spins per slot.
Result: Our average RTP recorded across all slots was 92.92%, compared to an advertised average RTP of 92.28%.
However, most slots did not land within the expected range. Some hit up to 178.10% whilst others sunk as low as 54.90%.
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KEY FINDINGS FROM 10,000 SLOTS SPINS
- Highest RTP recorded: 178.10% (Rainbow Riches Pick N’ Mix)
- Lowest RTP recorded: 54.90% (Book of Dead)
- Average RTP across all slots: 92.92%
- The more bonus games/free spins triggered, the higher the RTP becomes
WHAT IS RTP IN SLOTS?
RTP (Return To Player) is the percentage of total wagered money that a slot machine returns to a player over time.
The Formula:
RTP = (Total Returned ÷ Total Wagered) x 100.
Example:
If you wager £100 and receive £95 in return, your RTP is 95%.
WHY WE RAN THE TEST
RTP (Return To Player) is one of the most quoted numbers in online slots but it is also one of the most misunderstood.
Casinos are legally obligated to advertise the RTP of any given slot and they advertise it as a long-term average, often over millions of spins. But given no player is going to spin a slot anywhere close to a million times means that we have to look at it a slightly different way. What actually happens in a short session?
If you sit down and play 500 spins, how likely are you to get anything close to that number? We wanted to test exactly that. Given that a player is going to spin closer to 500 spins in a given session compared to 1 million, we will witness the real RTP of the slots.
OUR SLOT TEST METHODOLOGY
In order to keep things consistent and fair, we used the same setup across all 20 slots.
- Total slots tested: 20
- Spins per slot: 500
- Total spins across all 20 slots: 10,000
- Stake per spin: £0.20
- Total wagered per slot: £100
- Play style: Manual spins
- Time period: Single continuous session per slot
- RTP calculation: (Total returned ÷ Total wagered) x100
Important: This is a short-term RTP test, not a simulation of millions of spins.
LIMITATIONS
The average time it takes to spin through 500 spins on a slot is 40 minutes. 500 spins may sound like a lot but in reality it is still a small sample size. Slots in general are volatile, so short term results can vary wildly from theoretical RTP.
The test we have conducted reflects real player experience, not long-term mathematical averages. All slots were played at Casumo Casino and we therefore used the RTP of each individual slot game when played at Casumo Casino. We played slots from 15 different developers playing low, medium and high variance slots so that the sample was large and mixed full of different slot games.
FULL RESULTS – ADVERTISED RTP VS REAL RESULTS
Below is the full comparison of actual slot RTP results versus advertised RTP percentages based on our test of 500 spins per slot.
| Slot Game | Provider | Advertised RTP | Actual RTP | Difference |
|---|---|---|---|---|
| Aztec Tribute | Red Tiger | 92.9% | 146.96% | +54.06% |
| Starburst | NetEnt | 94.05% | 76.66% | -17.39% |
| Duck Hunters | NoLimit City | 92.04% | 84.72% | -7.32% |
| Book of Dead | Play N’ Go | 91.25% | 54.90% | -36.35% |
| MeJUICEa | Thunderkick | 94.18% | 69.46% | -24.72% |
| Book of 99 | Relax Gaming | 99.00% | 74.05% | -24.95% |
| Marching Legions | Relax Gaming | 98.12% | 70.88% | -27.24% |
| Razor Returns | Push Gaming | 94.49% | 72.88% | -21.61% |
| Gonzo’s Quest Megaways | NetEnt | 92.71% | 68.76% | -23.95% |
| San Quentin manhunt | NoLimit City | 92.07% | 97.17% | +5.10% |
| Oodles of Noodles | Pragmatic Play | 92.04% | 105.50% | +13.46% |
| Push The Button | Four Leaf Gaming | 92.10% | 88.10% | -4.00% |
| Rainbow Riches Pick N’ Mix | Barcrest | 92.03% | 178.10% | +86.07% |
| Le King | Hacksaw Gaming | 92.25% | 91.30% | -0.95% |
| 10 Swords | Push Gaming | 94.41% | 113.90% | +19.49% |
| Thoro | Elk Studios | 94.0% | 97.97% | +3.97% |
| Bonanza Megaways | Big Tie Gaming | 96.00% | 79.93% | -16.07% |
| Pirates Plenty: Battle For Gold | Red Tiger | 92.70% | 56.28% | -36.42% |
| Lucky Leprechaun | Microgaming | 96.33% | 104.22% | +7.89% |
| The Goonies | Blueprint Gaming | 93.06% | 126.68% | +33.62% |
The graph below also showcases the results of our test.
We also recorded all 20 individual tests which you can watch for yourself on the Slotshawk YouTube channel.
You can try any of these slots yourself by simply clicking on the individual reviews or play them all at Casumo Casino like we did!
SLOTS THAT PAID ABOVE ADVERTISED RTP (OVERPERFORMERS)
In total, eight out of the 20 slots performed above their RTP level. The biggest overperforming slot that we played was by far Rainbow Riches Pick N’ Mix which performed at 86.07% above its advertised RTP of 92.03%. This was due to the fact that we hit a 500x multiplier during the bonus.
Aztec Tribute by Red Tiger also performed well-above expectations. Its RTP came out at 146.96%, that’s +54.06% above its advertised RTP of 92.90%.
The Goonies slot by Blueprint Gaming was the game that impressed us the most because we were almost always in profit for the duration of the game.
Slots that outperformed their expected RTP:
- Rainbow Riches Pick N’ Mix: +86.07%
- Aztec Tribute: +54.06%
- The Goonies: +33.62%
- 10 Swords: +19.49%
- Oodles of Noodles: +13.46%
- Lucky Leprechaun: +7.89%
- San Quentin Manhunt: +5.10%
- Thoro: +3.97%
In terms of actual results, the above slots can be classified as high RTP slots.
Rainbow Riches Pick N’ Mix is at the top of this list because we hit a 500x multiplier during one of the bonus games, this short term variance meant that one big payout significantly increased the actual RTP by the end of the session.
SLOTS THAT PAID BELOW ADVERTISED RTP (UNDERPERFORMERS)
Two slots came out almost joint level for their RTP underperformance, Book of Dead by Play N’ Go and Pirates Plenty Battle for Gold by Red Tiger. These slots ended up being low payout slots for us which did not pay.
Book of Dead came out with an RTP underperformance of -36.35% giving it a lowly actual RTP of just 54.90%. Pirates Plenty Battle for Gold came out slightly worse with an RTP underperformance of 36.42%.
In total 12 out of the 20 slots underperformed their RTP level.
Slots which underperformed their expected RTP:
- Pirates Plenty: Battle For Gold: -36.42%
- Book of Dead: -36.35%
- Marching Legions: -27.24%
- Book of 99: -24.95%
- MeJUICEa: -24.72%
- Gonzo’s Quest Megaways: -23.95%
- Razor Returns: -21.61%
- Starburst: -17.39%
- Bonanza Megaways: -16.07%
- Duck Hunters: -7.32%
- Push The Button: -4.00%
- Le King: -0.95%
Why did the above slots underperform their expected RTP? The simple explanation is that we triggered less bonus rounds when playing these slots. It is during the bonus rounds where the majority of the wins occur whilst base games more often than not will drain your money.
KEY FINDINGS
As you can see in the table, some slots massively overperformed, some underperformed and some were just about what could have been expected.
These results surprised us somewhat. We did not expect as many as eight of the slots to perform above their advertised RTP. Although with that being said, we only made an overall profit in six out of 20 slots. Out of those six slots, one had low volatility, three were of medium volatility, one was high volatility and the final one had extreme volatility.
We did discover that the key to performing above expectations is by triggering the games main features – the bonus rounds. All of the slots that overperformed their RTP’s had one thing in common – we were able to trigger the bonus rounds/free spins games several times.
Essentially, the more often you can trigger bonus games, the greater the likelihood of coming out with a profit.
Volatility also plays a factor here too. The majority of the slots which underperformed are high volatility slots. Slot volatility’s relationship with RTP is complex.
Top Tip – Play the slots which have bonus features which are triggered often. Aztec Tribute is a great example of this because even though it has extreme volatility, you can trigger a mini version of free spins in the base game. The Goonies is another example of a slot with regularly triggered bonus features.
RTP VS REALITY: WHY THE GAP?
RTP is calculated over millions of spins, not hundreds. In a 500 spin session:
- Bonus rounds and free spins may not trigger at all or may trigger well-under average.
- Single big wins can inflate the results as shown during our test with Rainbow Riches Pick N’ Mix where we hit a single 500x win.
- Variance is a dominating factor when it comes to the outcome of a slot.
For this reason, actual results look nothing like the advertised RTP in the short term. If we were to run this test again, it is almost certain that all of the slots will come out with a different actual RTP. All slots use a RNG (Random Number Generator) and this has a huge impact on a short term basis.
WHAT THIS MEANS FOR PLAYERS
If you are a casual slots player, then here is the reality:
- RTP is not a guarantee for your session. Whether a slot has an RTP of 99% or 92%, the actual RTP when you play is highly likely to be above or below the advertised RTP.
- Short session (hundreds and even thousands of spins) are dominated by luck and volatility.
- High RTP slots are better in the long term, but not in the moment.
- Low and medium variance slots are more favourable
In simpler terms, RTP matters, but patience matters more.
Should you trust RTP? Well, RTP is a reliable long-term outlook. But, is RTP accurate in short sessions? Not really. Short sessions are unpredictable as we have proven in our tests, so the actual RTP can vary greatly.
That’s not a bad thing though. The unpredictability of online slots is one of the reasons why people enjoy playing them. If a slot guaranteed a certain outcome, then there would not be much point in playing them.
WHAT DOES THIS MEAN?
If there is one thing I personally learned from this experiment it is that in a short session of 0 – 10,000 spins, the RTP is not really relevant.
Prior to this, I always would have recommended playing the slots with as close as RTP to 100% as possible. However, I now see the futility of RTP. What should matter more to you and myself when playing a slot is the following:
- How often/frequent the bonus rounds are triggered.
- Whether or not there are frequently triggered and well paying features in the base game.
RTP is absolutely real and mathematically correct – but only over a significant amount of time.
The more spins you get through, the more relevance the RTP has. But for the average slots player who will play less than 1,000 or even 5,000 spins in a single session, the actual RTP will swing wildly and is unlikely to match what is advertised simply because what is advertised is the result of millions of spin.
CONCLUSION
Our RTP experiment proves that the more bonus games you trigger, the higher the actual RTP becomes and thus, the more money the slot will return to you. The base game of all slots are pretty much there to drain your balance.
Our test also clearly shows:
Short term results can vary wildly from the theoretical RTP.
Some slots paid far more than expected, (Rainbow Riches Pick N’ Mix) whilst other paid far less (Pirates Plenty).
FAQ
No. It is enough to show variance and give an indication of a slot, but it is not enough to reflect true RTP.
Can you trust the advertised RTP?
Yes you can, but only as a long term average not as a session prediction.
Can RTP be manipulated by casinos?
Some slots have adjustable RTP settings which means that the casinos can choose the RTP level.
What is a good RTP for slots?
95% or higher is considered good.
Do high RTP slots pay more?
Over a long period of time they do, but in a short session of hundreds and even thousands of spins they do not necessarily pay more. You can try to find the slots with the best bonus rounds to increase your chances of payouts.
CONTRIBUTORS
Greetings, I’m Iain Fenton
Iain Fenton is dedicated to bringing to you the most up-to-date and honest reviews and opinions from the world of online slots.
SlotsHawk Journalist since 2024
