Click to expand

×

Book of 99 is a slot from Relax Gaming, released in 2021. The game uses a classic Book-style presentation with ancient artifacts, a mystical book, adventure-themed visuals, and a high RTP that became its main feature.

The game grid consists of 5 reels and 3 rows with 10 paylines. The theoretical RTP is 99.00%, which is noticeably above the average level for online slots. Volatility is high, the betting range is usually listed from 0.10 to 100, and the maximum win reaches 12075x the bet.

Game Features

• Wild symbols
• Scatter symbols
• Free Spins
• Expanding Symbols
• Bonus Meter
• Symbol Collection

The main special symbol is the book. It performs two functions: it substitutes for regular symbols as a Wild and triggers Free Spins as a Scatter. If 3 or more Book symbols land on the reels, the Free Spins bonus mode is activated.

The game also includes a Wild collection meter. Every Book/Wild that appears is added to the Bonus Meter. When the meter reaches 99 collected symbols, the player gains entry to the bonus mode even without the standard Scatter combination.

Bonus Mechanics

Free Spins are the key feature of Book of 99. At the start of the bonus, a special symbol is selected that can expand on the reels during the free spins. If enough of that symbol appears, it expands and helps form additional payouts on the active paylines.

Expanding Symbols make the bonus mode the main source of major potential. An especially strong result is possible if one of the high-paying symbols is selected as the expanding symbol.

Bonus Meter adds a long-term goal to the game. Even if the bonus does not trigger immediately through 3 Scatters, every collected Wild moves the player closer to the next entry into Free Spins. This makes Book of 99 feel more progressive than many classic Book slots.

Theme and Style

The slot has an adventure style with references to ancient treasures, a mystical book, and classic Book of games. The reels feature characters, artifacts, a book, card symbols, and special bonus icons. Book of 99 falls into the categories of Egyptian slots, Book slots, and video slots.

The visual style remains clear and traditional: a 5×3 grid, 10 paylines, large symbols, and a familiar bonus structure. The main focus is not on complex mini-games but on the high RTP, collecting books, and Free Spins with an expanding symbol.

Popularity Among Players

Book of 99 is popular among players from the United Kingdom, Canada, Germany, the Netherlands, Norway, Sweden, Finland, Denmark, and New Zealand. The game may appeal to users who enjoy Book-style mechanics, high RTP, Free Spins, and a simple structure without overloaded extra modes.

The slot suits players who prefer high volatility, fixed paylines, a Wild/Scatter book, and a bonus round where expanding symbols create most of the potential.