<p>Book of 99 Slot Review: Explore its 99% RTP, Greek mythology theme, features, and big win potential with free spins and expanding symbols.</p>
Some slots try to put in too much with overwhelming flashing effects and confusing features. Book of 99 by Relax Gaming is not that. It looks like a typical "Book of" slot, but one thing stands out: the massive 99% RTP. That is much higher than a lot of slots and truly gives players something to pay attention to.
Relax Gaming didn’t try to change the world; they kept the same format and added a Greek mythology theme and a better RTP. If you enjoy simple gameplay with a rewarding twist, Book of 99 will likely become one of your favorites.
Book of 99 explores Ancient Greece, but not the polished museum kind. This is more of an illustrated graphic novel where the heroes and monsters step out of the pages.
The base game appears simple, but once the free spins start, the design opens up to a bright, sunny Greek Arcadia that feels like a vacation from the grind.
The Book of 99 doesn't try to confuse you with a manual that is the size of Homer’s Odyssey. Here's the simple setup:
The controls are simplified for all devices. On mobile, it’s simply swipe-and-spin smooth. The controls are just as intuitive on the desktop.
This is where Book of 99 flexes:
The combination of these factors makes Book of 99 a perfect fit for grinders who want a fair chance, but also thrill seekers who want to experience that one big win.
Book of 99 takes the traditional “Book of” model and adds a twist by offering two paths to free spins.
Here is the twist. Every time a wild symbol lands in the base game, it fills up a meter on the side of the game. Fill all spots of the meter (99 totals) and then you get 10 free spins guaranteed. It's like a punch card for coffee, except instead of a free coffee, you will win possibly thousands of dollars in free spins.
Feature | Details |
| Developer | Relax Gaming |
| Release Year | 2021 |
| Theme | Ancient Greece, Mythology |
| Reels & Paylines | 5 reels, 10 paylines |
| RTP | 99% |
| Volatility | High |
| Max Win | 12,075× stake |
| Bet Range | 0.10 – 100 coins |
| Bonus Features | Expanding symbols, Free Spins, Collection Meter |
| Platforms | Desktop & Mobile (iOS, Android) |
So why take a look at yet another "Book of" slot? Here's the pitch:
It's a game that respects your time: you can casually spin or grind deep, and either way, you're getting more return than most of the slots offer.
Book of 99 is excellent, but does not claim to revolutionize. Instead, it improves a great formula by adding a 99% RTP, along with a fun mechanic of collecting wilds.
Yes, it is a high volatility slot, so it can take some patience, and not every session will feel like you and your dollars are on Mt. Olympus. However, if you persist, you could cash in big, and along the way, the game is surprisingly fun.
In the crowded slot market, if you do one thing right, you can stand out, and Book of 99 stands out for giving players a much better shot at winning. And really, isn’t that what we all want?
Book of 99 is a 5-reel, 10-payline slot from Relax Gaming, with a theme of Greek mythology, free spins, and an impressive RTP of 99%.
The game offers a 99% RTP, making it one of the highest RTPs in the slot sector of the gambling industry, which gives you, the player, a better long-term expectation compared to the majority of slots' RTPs of 96%.
Free spins can be triggered in two ways: any combination of 3 book symbols can activate free spins, or collecting 99 wilds, which fills a meter to trigger 10 free spins.
The max win is 12,075× your stake, possible through expanding symbols during the free spins round.