RTP

~96%

Volatilitet

Hög

Leverantör

Triple Edge Studios (Microgaming)

Mekanik

Book / Expanding Symbol

Spela nu på SpinEmpire

Book of Truth Slot Review: The Expanding Symbol Mechanic That Defines the Game

Spela demo Spela på SpinEmpire

What Is Book of Truth?

Book of Truth is a slot developed by Triple Edge Studios under the Microgaming network. It operates within the book-mechanic genre — a category of slots defined by a Book symbol that serves as both wild and scatter, and a free spins feature built around an expanding symbol that fills entire reels when it appears.

The game is classified as high variance. Most of the game's payout potential is concentrated in the free spins feature rather than the base game, and sessions without the bonus round are typically characterised by low returns. The mechanic is well-established and Book of Truth's take on it is a competent entry from an experienced studio operating within the Microgaming ecosystem.

Theme

The theme is occult and ancient manuscript — a Book of Truth framing that draws on esoteric, mystical aesthetics rather than a specific mythology. The visual design uses dark backgrounds with gold detailing, candlelight motifs, and aged parchment textures. The atmosphere is deliberate and somewhat austere, more focused on creating an arcane mood than narrative engagement.

There is no explicit story or character. The Book of Truth itself serves as the central symbol — simultaneously the game's title, its most important mechanic, and its primary visual element. The art direction is coherent and maintains consistent tone throughout.

Gameplay and Base Game Structure

Book of Truth runs on a 5-reel, 3-row grid with 10 paylines, all paying left to right from reel 1. The Book symbol acts as a wild, substituting for all standard symbols to complete payline combinations. Two or more Book symbols visible on the reels generate a scatter pay based on their count, even without triggering the bonus round.

Three or more Book symbols anywhere on the reels trigger the free spins feature. The base game mechanics are straightforward: standard payline wins, a wild that completes combinations, and a scatter that triggers the bonus. The game's variance comes almost entirely from the free spins round. Base game sessions without the feature are typically low-return extended sequences punctuated by occasional symbol wins.

Symbols and Paytable

The lower-paying symbols are card royals styled consistently with the game's dark aesthetic. The higher-paying symbols are thematic icons drawn from the occult and arcane theme:

• High-tier thematic symbols (specific icons aligned with the manuscript/occult theme)
• Card royals (A, K, Q, J, 10) — lower tier, styled in the game's palette
• Book of Truth — scatter and wild, highest single-symbol value and the mechanic pivot of the entire game

The exact paytable values are visible in the in-game help section. The premium symbol tier provides the meaningful payouts, while card royals contribute to win frequency without significant value.

RTP and Volatility

An RTP of approximately 96% is referenced for Book of Truth, though this figure has not been independently confirmed through official Microgaming documentation for this specific review. Players should verify the active RTP in the in-game information panel at their specific casino. Microgaming titles can be deployed with alternate RTP configurations by operators.

Volatility is high. This is structurally consistent with the book-mechanic format: the base game produces frequent low-value wins while meaningful payouts are concentrated in the free spins round, where the expanding symbol can produce large single-feature outcomes. Bankroll management appropriate to high-variance play is relevant here.

Bonus Features

Free Spins Trigger

Three or more Book of Truth symbols anywhere on the reels trigger the free spins round. The position of the Books does not matter — they do not need to appear on a payline, only anywhere on the visible grid. The trigger awards 10 free spins and selects one symbol to serve as the expanding symbol for the entire feature.

Expanding Symbol

At the start of the free spins round, one symbol is randomly selected as the expanding symbol. This symbol expands to fill entire reels when it appears during the feature. A reel fully covered by the expanding symbol pays on all paylines that include that reel. Multiple reels covered simultaneously produce the largest outcomes, particularly if the selected symbol is from the premium tier (pharaoh, high-value thematic icon).

The expanding symbol selection is random and the same symbol remains designated throughout the entire feature, including any retriggers. There is no player choice involved in the selection.

Retriggers

Landing three or more Book symbols during the free spins round adds 10 additional free spins to the remaining total. Retriggers use the same designated expanding symbol established at the start of the feature. There is no published cap on retrigger count.

Scatter Pays in Base Game

Two or more Book symbols visible on the reels in the base game produce a scatter pay. This pay is separate from the free spins trigger and occurs based purely on the number of Books visible, regardless of position. It provides occasional small-to-moderate wins in the base game between bonus triggers.

How to Play

Select your stake using the controls at the bottom of the interface. Press spin or set autoplay for a configured number of rounds. Three or more Books trigger the free spins automatically — the expanding symbol is chosen by the game at random, and the feature plays out without player decisions. After the feature ends or retriggers are exhausted, the game returns to the base game.

Mobile Performance

Book of Truth is built on HTML5 and performs across mobile and tablet devices. The 5x3 grid scales cleanly to both portrait and landscape orientations. The expanding symbol animation is clear and legible on smaller screens. Triple Edge Studios titles within the Microgaming network are consistently optimised for mobile environments.

Demo Mode

A free play demo of Book of Truth is available. The demo replicates the full feature set, including the free spins round and expanding symbol behaviour. Playing the demo is the recommended starting point before committing real money — particularly for understanding the variance profile of the book mechanic and how the expanding symbol selection affects individual feature outcomes.

Similar Slots

• Book of Dead — Play'n GO. The genre-defining title in the book mechanic category. Same structural format: book wild/scatter, expanding symbol free spins.
• Eye of Horus — Blueprint Gaming. Egyptian-themed book mechanic with a different approach to symbol values and free spins structure.
• Book of Ra — Novomatic. The original mainstream title in the book-mechanic genre. Classic presentation, widely available.
• Tome of Madness — Play'n GO. Book mechanic with additional complexity: cluster pays variant using the book concept in a Lovecraftian theme.

Frequently Asked Questions

Who developed Book of Truth?

Book of Truth was developed by Triple Edge Studios, a studio operating within the Microgaming network. It is distributed through Microgaming's platform to licensed online casinos.

What is the RTP of Book of Truth?

An RTP of approximately 96% is referenced, though this should be verified in the in-game information panel at your specific casino. Microgaming titles may be deployed with alternate RTP configurations by individual operators.

How does the expanding symbol work?

At the start of the free spins round, one symbol is randomly selected. During free spins, whenever that symbol appears on any reel, it expands to fill the entire reel. The expanded symbol pays on all applicable paylines. The same symbol remains designated throughout the feature, including any retriggers.

How many free spins does Book of Truth award?

Three or more Book of Truth symbols trigger 10 free spins. Retriggers during the feature add 10 additional spins per occurrence. There is no published maximum on retriggers.

Is Book of Truth available to play for free?

Yes. A demo version is available at SpinEmpire that replicates the full mechanics, including the free spins feature. No registration or deposit is required to access the demo.