A New Take on Cluster Slots: Book of Monsters

A New Take on Cluster Slots: Book of Monsters

Pragmatic Play

Rated 97.15/100%

452 Casinos
628 Games | 33 Live Games

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Number of games

628

Country

Malta

Founded

2015

• Live Games
• Slots
• Tournaments

Pragmatic Play has launched Book of Monsters, a cluster-based slot incorporating symbols capable of expanding across the reels. The game's structure allows for symbol sizes ranging from standard single-cell icons to larger formations reaching up to 7×7. This mechanic introduces variability to the gameplay, where symbol expansion occurs at random, creating shifting patterns across the grid.

In the base game, any spin can result in the appearance of oversized symbols, which can influence the outcome by covering multiple positions at once. The unpredictability of their placement adds a layer of dynamic engagement, shaping the potential payout structure in a way that differs from traditional reel-based slots.

94.85/100%

New

Play for free Play for real

RTP%

96.5

Volatility

High

Layout

7×7

Max Win

Book of Monsters

No star

9 plays

27/03/2025

Pragmatic Play

The bonus round in Book of Monsters is activated when four to seven scatter symbols land on the reels, triggering a sequence of free spins. The number of free rounds awarded varies, with a minimum of five and a maximum of eight. A key element of this feature is the designation of a FAT symbol, which is selected randomly at the start of the round.

Before the free spins begin, the game offers an optional gamble feature. This allows players to attempt to increase the total number of free spins while also upgrading the FAT symbol to a higher-value variant. This mechanic introduces risk, as the decision to gamble comes with potential advantages and the possibility of not securing an upgrade.

Once the free spins are underway, the FAT symbol shifts positions on each spin. When matching symbols land on the grid, they are collected and stored in a meter. As more symbols accumulate, the FAT symbol gradually expands, growing from an initial 2×2 size to larger configurations. If enough matching symbols are collected, the symbol can reach its maximum size of 7×7. Each stage of expansion awards additional free spins, ranging from one to three, which extends the duration of the bonus round.

According to Irina Cornides, Chief Operating Officer at Pragmatic Play, Book of Monsters incorporates a design that allows for evolving symbol sizes and a payout structure that adapts dynamically during play. The game's model offers the potential for maximum payouts of up to 5,000 times the base bet.

Pragmatic Play has consistently introduced slot formats that diverge from conventional pay line mechanics. Book of Monsters' cluster-based structure, combined with the progressive growth of key symbols, reflects an approach focused on diversifying how wins are calculated and how bonus rounds develop.

The introduction of Book of Monsters aligns with Pragmatic Play's broader strategy of incorporating non-traditional mechanics into its game catalog. While many of the provider's previous releases have explored variations of expanding symbols, this slot's integration of symbol progression into both the base game and bonus round offers a distinct take on this feature.

By adding Book of Monsters to its portfolio, Pragmatic Play continues to develop slot titles that feature mechanics designed to create variability in winning combinations. The interplay between symbol growth, shifting positions, and accumulating meters contributes to an evolving gameplay structure that differs from static slot formats.