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Book of Monsters

Game Experience
Graphics
Bonuses

Software Provider

Games Global

Reels

5

Volatility

High

Payout

96.86%

Winning Lines

243

Freespins

Yes

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Book of Monsters is a spine-tingling Slot from Pragmatic that tosses you into a creepy realm filled with monstrous creatures. You’ll see a 5×3 grid (five reels, three rows) plastered with all sorts of ghoulish icons, and it’s your mission to align these symbols across active paylines for cash prizes.

The real kicker here is the game’s special “Book”symbol, which not only acts as a scatter but also helps unlock the main bonus feature. If you fancy a shot at taming mythical beasts while chasing big wins, then you’re definitely in the right crypt.

So what’s the core game loop? You’ll place your bets, starting from as little as £0.20 and scaling up to a hefty £480 if you’re feeling bold, and spin the reels. Land three or more matching symbols on an active payline from left to right, and you’ll score a payout.

Book of Monsters

Book of Monsters also comes with a ferocious free spins round, so keep your eyes peeled for scattered “Book” icons. You land them, you crack open that secret chamber, and you reap the spoils. No second chances, miss out on the required scatter count, and you’ll have to spin again until hungry luck decides to show up.

Theme and Graphics

The first moment Book of Monsters loads, you’ll notice its unapologetic horror vibe. Think dark corridors lit by flickering torches and ancient volumes stacked in a shadowy crypt. The monsters themselves look like they stepped out of a vintage scary film, fangs, claws, glowing eyes, the works.

Each symbol is meticulously drawn, from ghastly gargoyles to cunning imps, giving the reels a heavy infusion of menace. It’s as if you’re flipping through an ancient bestiary you really shouldn’t be messing with.

Animation-wise, there’s a subtle but effective approach: you’ll see dripping slime effects around some key symbols, and watch out when you form a winning line, the creatures come alive with a faint roar or a hiss. Meanwhile, the soundtrack is pure gloom, composed of haunting chants and shivery strings that build tension over time.

Throw in a few sudden shrieks, and you’ve got yourself an unsettling atmosphere that actually keeps the adrenaline pumping. It’s not just for show, either. Having a dark, moody setting can really lean into the excitement of hitting those bigger wins, almost like you’re releasing a monster from its cage every time the reels light up.

Gameplay and Features

Book of Monsters Slot

Reel Layout and Paylines

Pragmatic keeps it straightforward with a 5×3 reel layout: that’s five reels horizontally and three rows vertically. It’s a standard setup, so if you’ve played a bit of slots before, you’ll feel right at home.

The game offers 10 fixed paylines, which means you can’t adjust the lines, they’re always on. Why is that good? You never miss out on a potential winning payline because it’s deactivated. This slot also comes with a special expanding symbol mechanic during free spins, but we’ll get to that cryptic treat later.

Unlike more elaborate Megaways or Cluster Pays titles, Book of Monsters doesn’t rely on complicated reel expansions or cascading features. Instead, it banks heavily on that traditional approach where each reel spin is separate, and you line things up the old-fashioned way.

Don’t let that fool you, this slot can still whip up monstrous payouts, especially if the expanding symbol turns up at just the right time.

Winning Combination

To score a win, you’ll need to line up at least three matching symbols from the leftmost reel to the right on one of the 10 paylines.

Typical lower-tier icons include some stylised playing card symbols from 10 through Ace, each with a cunning twist, maybe a bit of slime or scratches, to suit the monstrous theme. The bigger monsters, naturally, pay substantially more. If you’re lucky enough to land five of the top-tier creatures or the special “Book” symbol across a line, you can walk away with a tidy sum.

The slot leans toward medium-to-high volatility, so wins might not strike relentlessly, but when they do, you can often see a jump in your bankroll. In my view, it’s like torqueing a bolt too tightly, and sometimes, you just have to be patient and apply steady pressure.

You’ll notice smaller, more frequent hits aren’t exactly the hallmark here, though you might catch a series of moderate payouts that keep you in the game until the free spins roll in.

Special Symbols

Let’s talk about the star of the show: the “Book of Monsters” icon. This symbol pulls double duty as a Wild and a Scatter. It stands in for regular icons when generating standard payline wins, which is handy.

But the real thunder comes when you land three or more Books anywhere on the reels, left, right, centre, doesn’t matter. That’s your ticket to the bonus round and the free spins feature. Visually, it’s a battered tome with faint glowing runes, so you can’t miss it amongst the monstrous faces.

Bonus Rounds and Free Spins

How to Trigger Bonuses

Unlocking the marquee feature, which is free spins, requires snagging at least three Book symbols anywhere in a single spin. Take note that you don’t need them to line up on a payline; they just have to appear.

Once you see three, four, or five, the game transitions to the free spins phase, awarding you 10 free spins as a base. There’s no official Bonus Buy option lurking in the shadows for Book of Monsters, at least not in the majority of regions. So if you’re itching to jump straight to the free spins, you’ll have to rely on some old-fashioned good fortune.

If you’re accustomed to some of Pragmatic’s other titles, you might know about features like Ante Bet or Shortcut Bonus Buys. That’s not the approach in this slot, so you’ll do it the classic way, spin away, watch for those glowing tomes, and hope the reel’s aura is bright that day.

Special Mechanics

Once your free spins load up, the slot selects one random standard symbol to be an expanding icon for the duration of those spins.

Whenever that symbol appears in sufficient quantities on the reels, it expands vertically to cover the entire reel (or reels) and pays out even if the combos aren’t in adjacent order. That means you can land some surprising hits if luck lines up your chosen symbol frequently.

What’s great is that this expanding mechanic can drastically boost your payout potential. Imagine getting the top-paying monster as your chosen symbol, hitting a few more on each spin, and your entire screen can turn into a mass of that creature, culminating in a monstrous win.

The free spins can also retrigger if you land three or more Books again, granting an additional 10 free spins. It’s a bit like building a gaming rig: if you get all the high-end parts lined up, you’re in for a fierce performance boost.

Progressive Jackpots (if applicable)

Book of Monsters doesn’t feature a progressive jackpot. It’s more of a stand-alone beast with a fixed max payout, focusing on those free spins to deliver the bigger hits. Some of us love that random jackpot excitement, where the prize pot grows over time, but here, you’ll just rely on the standard paytable and those well-timed expansions.

Could be wrong, but this pattern rarely lies: if you prefer full control and a clear path to a set max win, you’ll be completely fine without a progressive element.

Payout Potential and Volatility

RTP Explained

The theoretical RTP (Return to Player) of Book of Monsters stands at 96.50%, which is a pleasant figure in the modern slot landscape.

Typically, you see most online slots hovering around the 96% mark. So, 96.50% is just that little bit sweeter. In essence, that’s the average payback you can expect over, say, a million spins. Of course, we humans rarely play a million spins ourselves, but it’s good to know you aren’t dealing with something severely below par.

If you’re brand new, imagine the RTP as a broad measure of fairness. Over time, if you dropped £100 in bets, you might expect around £96.50 back, but that’s in the long haul. Shorter sessions can always defy the averages, for better or for worse.

Volatility

This slot leans towards medium-high volatility. What does that mean practically? You’re going to see fewer frequent micro-wins and more moderate or substantial hits spaced out. As you spin, you might experience some lulls, but once you strike a big combination, especially during free spins with expanding symbols, the lumps of gold can be significant.

Is that risk style for everyone? If you’re a cautious player who loves lower volatility games that regularly cough up small prizes, you might find Book of Monsters a tad nerve-racking. But if you’re the type who’s happy to ride the wave of near misses until the free spins land, you’ll feel right at home.

Max Win Potential

The max win is typically pegged at around 5,000x your stake, a common sweet spot for these “Book of…” style slots. Pull it off on the top bet of £480, and well, you do the math, things get hefty in a hurry.

Achieving that monstrous figure usually hinges on nailing the free spins with the highest-value symbol as your expanding icon and a nice dose of reel luck. Think of it like discovering a hidden compartment in your battered old spellbook: you stumble upon it, and your entire night’s made.

For perspective, here’s how it compares to some popular entries in the genre:

  • Book of Ra: Up to 5,000x
  • Legacy of Dead: Up to 5,000x
  • Book of Monsters: Up to 5,000x

So Book of Monsters keeps pace with its monstrous peers.

Playing Book of Monsters on Mobile

If you prefer to spin on your phone or tablet, Book of Monsters is fully optimised for mobile. It runs seamlessly on iOS and Android alike, and if you have an up-to-date browser (Chrome, Safari, or Firefox), you should be ready to rock.

The visuals scale nicely onto smaller screens, so you won’t suffer from squint-and-guess icon syndrome. The interface remains clean, with easy betting adjustments via plus and minus icons, and convenient spin buttons that respond swiftly to taps.

The dark, shadowy background and neon highlights translate perfectly to mobile, keeping you immersed if you decide to play while commuting, or, you know, while you’re perched on the sofa late at night.

Performance holds up, too: no stutters or lags, at least in my experience, and the animations are just as crisp as on desktop. In the end, it’s a slot that doesn’t care if you’re on a phone, tablet, or a laptop from 2013; you’ll get the same monstrous world right in your pocket.

Pros

Thumbs Up Gripping horror theme with top-notch visuals and ambience.

Thumbs Up Expanding symbol mechanic in free spins that can deliver colossal wins.

Thumbs Up Respectable RTP at 96.50%.

Thumbs Up Wide betting range (from £0.20 to £480).

Cons

Thumbs Down Medium-high volatility can be punishing in cold streaks.

Thumbs Down Lacks a progressive jackpot or extensive secondary bonuses.

Thumbs Down Ten paylines might feel a bit restrictive to some players.

Play Responsibly

Always remember: gambling should be entertaining, not a stress-filled chase. If you ever feel it’s getting out of hand, step back. You can set deposit limits, reality checks, or cooling periods at most reputable casinos.

Feeling overwhelmed? Get in touch with resources such as GamCare or BeGambleAware for support. It’s important to keep your bankroll in check, just like you’d watch the temperature on your gaming rig to avoid overheating.

Final Verdict on Book of Monsters Game

Book of Monsters checks off many boxes if you’re a fan of high-octane spins with a classic “Book” mechanic twist. The monstrous theme isn’t just a throwaway, it sets a moody stage that amplifies the thrill when those free spins land and your chosen symbol expands.

It’s best suited for players ready to ride the roller-coaster of medium-to-high volatility. If you enjoy building up suspense and aiming for meaty payouts, Book of Monsters is definitely worth a spin.

Adam Nadeau
Adam Nadeau Author

Adam Nadeau is our site founder, reviewer and director of sales with 19 years of experience in the online gambling industry. He started PlayCasinos out of his college dorm room in 2005 as a personal blog, where he shared his favourite slots and ga...

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