Book of 99

Book of 99: A Relax Gaming Slot with a Legendary RTP

Game Overview & Theme

The visual presentation is crisp and polished, typical of Relax Gaming's high production standards. However, the true treasure here isn't buried in a tomb—it's built into the game's mathematical core. The title "99" is your first clue that this game operates differently. It forgoes the traditional scatter and wild symbols in the base game for a singular, powerful Book symbol that acts as both, setting the stage for its unique selling point.

How to Play Book of 99

Book of 99 is built on a straightforward 5-reel, 3-row grid with 10 fixed paylines. Wins are formed by landing matching symbols on consecutive reels from the leftmost reel. The lower-value symbols are the classic 10-A card royals, styled with a hieroglyphic flair, while the higher-value symbols are the thematic icons like the horned figure, the ogre figure and the gold-framed twin figures. The most important symbol is the gilded Book, which serves as the game's special symbol.

The Groundbreaking 99% RTP

This is where Book of 99 makes its mark. Unlike virtually every other video slot where the Return to Player (RTP) is a fixed, hidden percentage, Book of 99 proudly operates with a fixed RTP of 99%. This is a high theoretical return, significantly above the industry average. For a deeper understanding of how RTP interacts with game behavior, check out our guide on Slot Variance vs Volatility.

Special Features & Bonus Rounds

The feature set in Book of 99 is elegantly simple, focusing all the excitement on one major bonus event.

The Book Symbol: The gilded Book acts as both the Wild and the Scatter symbol. As a Wild, it can substitute for any regular pay symbol to help form winning combinations. As a Scatter, landing three or more Book symbols anywhere on the reels triggers the Free Spins feature.

Free Spins Feature: Landing 3 or more Book scatters awards 10 free spins, and collecting 99 books in the base game also triggers 10 free spins. Before the free spins begin, one regular paying symbol is randomly chosen to become an Expanding Symbol. During the free spins round, if you land enough of this chosen symbol to form a win (even just 2 of a kind), that symbol will expand to cover all positions on its reel, potentially creating big wins across all paylines. This is where the game's medium volatility is most apparent, offering the potential for significant payouts during the bonus round.

Volatility & Betting Strategy

Book of 99 is classified as a medium volatility slot. This means it strikes a balance between the frequency of wins and the potential size of payouts. You can expect a steadier stream of smaller wins compared to high volatility slots, with the free spins round holding the key to the bigger prizes. A common strategy in medium-volatility games like this is to find a bet size that allows for sustained play, patiently waiting for the free spins trigger where the main winning potential is unlocked. Remember, you can always test different approaches risk-free with the demo version.

Play Book of 99 for Free on Slottomat

The best way to experience the unique mechanics of Book of 99 is to try it without any financial risk. We offer the complete, unrestricted demo version of the game. You can spin the reels, trigger the free spins bonus, and see how the expanding symbol feature works, all using virtual credits. It's the easiest way to learn the game's rhythm and decide if its legendary RTP structure and theme are right for you before playing anywhere else.

Where to Spin Next

If you enjoy the theme or mechanics of Book of 99, Relax Gaming has several other top-tier titles you should explore:

• Temple Tumble Megaways: Explore a cascading reel adventure with the popular Megaways mechanic in this ancient ruin-themed slot.


• Temple Tumble 2: The sequel builds on the original with enhanced features and even more ways to win.


• Galactic Wilds: For a theme shift, this space adventure offers wild re-spins and cosmic payouts.


• Mummy Multiplier: Stay in Egypt with a slot focused on growing multipliers during its free spins round.


• Fly Cats Dream Drop: Experience Relax Gaming's progressive jackpot network in this playful, feature-rich game.

If you prefer simpler classic-style games, browse our collection of Free Fruit Machines.