Book of 99 and Mega Joker lead this comparison with published RTP figures of 99%. Jackpot 6000 follows at up to 98.90%, while 1429 Uncharted Seas, Marching Legions and Blood Suckers also publish returns of 98% or higher.
The highest percentage does not tell you everything about a slot. You may prefer a straightforward five-reel game, a lower-volatility option or a classic slot with separate playing modes. Below, we compare six high RTP online slots and explain the differences worth checking before you choose.
High RTP Online Slots Compared
Compare six games from NetEnt, Relax Gaming and Thunderkick, ordered by their published RTP.
| Slot Game | Provider | RTP |
| Book of 99 | Relax Gaming | 99% |
| Mega Joker | NetEnt | 99% |
| Jackpot 6000 | NetEnt | Up to 98.90% |
| 1429 Uncharted Seas | Thunderkick | 98.60% |
| Marching Legions | Relax Gaming | 98.12% |
| Blood Suckers | NetEnt | 98% |
RTP figures are based on official provider information. Check the in-game rules for the RTP and conditions that apply at your casino.
Book of 99
Book of 99 combines a Greek mythology theme with expanding symbols during free spins. The bonus can be triggered by landing three book symbols or collecting 99 books in the base game.
For players comparing “Book of” slots, its 99% published RTP makes it worth examining. The collection feature adds another route to free spins, but reaching the bonus does not guarantee a profit.
Mega Joker
Mega Joker is a classic three-reel slot with five fixed paylines and a separate Supermeter mode. Winnings from the basic game can be wagered again in that mode, which has its own bet options and paytable.
Jackpot 6000
Jackpot 6000 offers a traditional three-reel layout, Supermeter play and an optional double-up feature. NetEnt advertises its RTP as “up to” 98.90%.
The main point for players is understanding when winnings are collected and when they are put back at risk. Check the Supermeter and double-up rules before treating its headline return as directly comparable with a simpler slot.
1429 Uncharted Seas
1429 Uncharted Seas features five reels, 25 paylines, expanding wilds and free spins. Thunderkick lists a 98.60% RTP and classifies the game as low volatility.
If you prefer lower-volatility slots, 1429 Uncharted Seas is one to compare. However, low volatility does not guarantee a profit or that your balance will last longer.
Marching Legions
Marching Legions uses marching stacks, respins and collection mechanics to unlock free spins. Relax Gaming publishes a 98.12% RTP and classifies it as highly volatile.
It offers a different style of play from 1429 Uncharted Seas, despite both having high published returns. If large swings in your balance would make the game uncomfortable, the volatility is more useful to consider than the RTP alone.
Blood Suckers
Blood Suckers is a vampire-themed slot with 25 paylines, wild symbols and free spins. It provides a conventional five-reel alternative to the Supermeter games in this comparison.
The published 98% RTP belongs to the original Blood Suckers. Check the full title in the casino lobby: Blood Suckers 2 is a separate game with a published RTP of 96.94%.
Looking for games from a particular developer? Our comparison of Pragmatic Play slots with the highest RTP focuses on that provider’s titles.
How Do High RTP Slots Compare with Low RTP Slots?
Higher RTP means a lower theoretical house edge, but it does not necessarily mean more frequent wins or lower volatility. Our guide to high RTP vs low RTP slots explains how the two compare and what RTP can tell you about a game.
How to Choose Between High RTP Slots
Once you have compared the percentages, narrow your choice by looking at how the game works:
- Volatility: Decide whether you are comfortable with the payout variation described by the provider. High RTP does not automatically mean low volatility.
- Rules and features: Check whether you understand the base game, bonus triggers and any separate modes before putting money at risk.
- Total bet: Look at the full cost of a spin, including any optional feature charges. A higher stake puts more money at risk even when the RTP stays the same.
If the terminology is unfamiliar, our guide to RTP and volatility in slots explains what each measure tells you.
How Do High RTP Slots Compare with Low RTP Slots?
A higher RTP means a lower theoretical house edge. For example, a slot with 98% RTP has a theoretical house edge of 2%, compared with 4% for a slot with 96% RTP.
However, this does not tell you which game will pay more during your next session.
How to Check the RTP at Your Casino
Open the exact game you intend to play and check the following:
- Confirm the title and provider. Similar names and sequels can have different returns.
- Open Help, Information or the paytable. Find the theoretical RTP shown for that game.
- Check your chosen mode. The main game, Supermeter mode and bonus buy options may have different RTP figures.
- Check any mismatch. If the in-game figure differs from a published listing, do not assume the higher number applies.
Demo play can help you understand the features, but a short session cannot verify RTP. Playing longer also does not guarantee that your results will match the advertised percentage.
For more on paylines, game features and slot mechanics, see Ugrado’s online slots guide.
Frequently Asked Questions (FAQ)
Book of 99 and Mega Joker both have published RTP figures of 99%. Check the exact game’s rules for the applicable return and playing conditions.
No. RTP refers to the theoretical return on total wagers over a very large volume of play. It does not guarantee a return on your deposit or session.
Not necessarily. RTP describes theoretical return, while hit frequency describes how often a payout occurs. A payout can also be smaller than your stake.
A larger stake alone does not establish a higher return percentage. Only rely on a difference explicitly stated in the game’s rules, and remember that larger wagers increase the amount at risk.
Availability varies by casino. Search for the exact title in the game library, then confirm its RTP and rules before playing.
Set a spending limit before playing and use only money you can afford to lose. A high RTP does not make slots a reliable source of income.
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