Book of Power is another collaboration between Relax Gaming and CasinoGrounds. Their previous teamups gave us Net Gains, Beast Mode, and Iron Bank. All solid slots. This time they went with the classic book genre but added their own twists.

I wanted to check this out because Relax Gaming usually does something different even with familiar formats. They kept the expanding symbol mechanic but added multipliers that can stack up to 9x. Plus a Power Bet option and Power Free Spins for players who want more risk.

Here's what I found.

Game Overview

Provider Relax Gaming / CasinoGrounds
Game Type Video Slot
Grid 5 reels
Paylines 10 fixed lines
RTP 96.11% base, 96.5% bonus buy (variants: 94%, 90%)
Volatility High
Max Win 15,000x
Min/Max Bet €0.10 to €60
Bonus Buy Yes (100x and 200x)

RTP Note: Bonus buy RTP jumps to 96.5% which is nice. Some casinos run 94% or 90% versions. Check before playing.

How It Looks

Egyptian theme but with a more realistic style than most book slots. Reminded me of Push Gaming's Mystery Museum mixed with some Print Studios vibes.

The background has that ancient temple feel. Numbers line the grid giving it that classic book genre look. The explorer character and Egyptian artifacts fit the theme well.

Audio matches the visuals. Builds tension during spins and gets exciting when features trigger.

Base Game

10 fixed paylines. Match symbols left to right.

Low symbols are card royals 10 through A. High symbols are three Egyptian artifacts plus an explorer as the top pay.

Payouts for 5 of a kind:

Low symbols: 10x to 15x

Premium symbols: 75x to 500x

That 500x for five explorers is solid. Most book slots cap premiums lower.

Book Symbols

Two types of books in this game.

Regular Book: Wild symbol. Substitutes for any pay symbol. Also acts as the scatter.

Power Book: Same wild function but triggers Power Free Spins instead of regular free spins.

Both books contribute to triggering the bonus.

Power Bet

Double your stake to activate Power Bet.

What you get:

  • 170% increased chance to trigger any free spins
  • Ability to gamble for Power Free Spins when regular free spins trigger

It's basically paying more for better odds at the bonus. The gamble option lets you risk regular free spins to upgrade them.

Free Spins

Land 3, 4, or 5 book symbols to trigger free spins.

Option Cost What You Get
Free Spins 100x Regular free spins
Power Free Spins 200x Power Free Spins with upgrade mechanics

At the start, a random pay symbol becomes the special expanding symbol.

How expanding symbols work:

When the special symbol can form a win, it expands to cover all positions on its reels. It pays all ways from any position.

Retriggers:

Land 2 books during free spins and a second expanding symbol is chosen. You also get +5 extra spins.

If the new symbol matches your current expanding symbol, it gets +1 multiplier instead. Multipliers can reach up to 9x.

Power Free Spins

If one of your triggering books is a Power Book, you get Power Free Spins instead.

Same spin amounts and instant payouts. But the mechanics work differently.

Key differences:

Land 2 books and your current expanding symbol upgrades by one step on the paytable. You also get +5 spins.

If you're already at the highest paying symbol, retriggers add +1 multiplier instead. Up to 9x.

Golden Reels:

Land a Power Book on reels 2, 3, or 4 and that reel becomes golden. Golden reels always show the expanding symbol even if it didn't actually land there.

This is where Power Free Spins gets good. Multiple golden reels with a high value expanding symbol and multipliers can create big wins.

Lucky Boost

Can trigger randomly at the start of any free spin in either feature.

Increases your chance of hitting something big on that spin. Nice little surprise when it pops up.

Bonus Buy Options

<table> <thead> <tr> <th>Option</th> <th>Cost</th> <th>What You Get</th> </tr> </thead> <tbody> <tr> <td>Free Spins</td> <td>100x</td> <td>Regular free spins</td> </tr> <tr> <td>Power Free Spins</td> <td>200x</td> <td>Power Free Spins with upgrade mechanics</td> </tr> </tbody> </table>

The bonus buy RTP is 96.5% for both options. Worth considering if you don't want to grind base game.

If you like bonus buy slots, both options are reasonably priced.

My Experience

I've had mixed results with this one. The regular free spins can disappoint if you get a low symbol as your expander.

Power Free Spins is where the potential lives. Getting the explorer as your expanding symbol, upgrading it to max multiplier, and landing golden reels changes everything.

The retrigger mechanic is clever. Instead of just adding symbols, you're upgrading what you already have. Feels more focused than slots that pile on random expanders.

Bankroll Advice

High volatility with 15,000x max win.

Bring at least 250 to 300x your bet. At €1 spins, that's €250 to €300 minimum.

The Power Bet doubles your stake so account for that if using it. The 170% better bonus odds might be worth it depending on your style.

Mobile

Works well on mobile. The 10 payline format is clean on smaller screens. Expanding symbols and golden reels display clearly.

Who Should Play This

Book of Power works for you if:

  • You like book genre slots
  • Expanding symbols with multipliers appeal to you
  • The upgrade mechanic sounds fun
  • Egyptian themes suit you
  • You want a polished Relax Gaming experience
  • 15,000x max win is enough

Skip this if:

  • You want something more innovative
  • Book slots feel overdone to you
  • You prefer more paylines
  • High volatility is too risky
  • You need higher max win potential

What I Liked

  • 15,000x max win is solid for the genre
  • 96.5% bonus buy RTP is great
  • Multipliers up to 9x on expanding symbols
  • Upgrade mechanic instead of adding random expanders
  • Golden reels in Power Free Spins
  • Power Bet gives options for higher risk
  • Clean visuals and presentation
  • Two bonus buy options

What I Didn't Like

  • Multiple RTP versions (check your casino)
  • 10 paylines is limited
  • Regular free spins can underwhelm
  • Power Bet doubles your stake
  • Genre is crowded with options

Final Verdict

Book of Power is a well made book slot. Relax Gaming and CasinoGrounds stuck with tradition but added enough twists to make it interesting. The upgrade mechanic for expanding symbols feels better than random additional expanders.

Power Free Spins is the real feature. Golden reels that always show your expanding symbol, upgrades that push toward higher paying symbols, multipliers stacking to 9x. When it connects, the 15,000x max win is reachable.

The book genre is crowded. Dozens of options exist. But Book of Power is polished, has personality, and the mechanics work together well. If you like book slots, this is a quality addition.

Worth playing if you enjoy the format and want something from a reputable studio with good RTP options.

My Rating: 3.5/5

Solid mechanics, good RTP on bonus buy, nice presentation. The crowded genre and limited paylines keep it from scoring higher. Best for book slot fans who want a reliable option with upgrade mechanics.