Book of Rrrum Slot Review
A wooden galleon rides choppy turquoise water, torn sail snapping above the reels, palm islands on the horizon and a half-buried treasure chest on the shore below. Most book slots let the expansion pay once and consider the job done; Book of Rrrum blows its expanded symbols up, deals in new ones, and keeps doing it while the multiplier climbs.
From ESA Gaming, it runs on a 5×3 grid with 10 paylines, an RTP of 96% and mid-to-high volatility. The specs are the familiar part. The bonus round that keeps paying after its first win is where this ship earns its sail.
Expanding Pay Anywhere Symbols
The scatter is the book itself: land three or more and the Free Spins feature triggers, while two books pay 2x the bet as a consolation. Beyond the scatter, one mechanic does the rest of the work, so the base game plays as a straightforward ten-liner with an eye on the books.
During Free Spins, a symbol is randomly selected on each spin. If three or more of that symbol appear, they expand to fill the entire reel. Expanded symbols don’t need to sit on adjacent reels to form a winning combination, so a full grid of the chosen symbol pays across every line at once.
The same expanding behaviour appears in the main game through the Boost function, with one difference: no multipliers attach to it there. The expansion rules are otherwise identical, and a well-timed main-game expansion can still pay across all ten lines.
Wins in the main game resolve the ordinary way: matching symbols on active paylines, highest combination per line, spin and collect. The expanding symbol is the only special beyond the scatter, and there’s no second bonus round hiding behind a symbol collection or a wheel.
Boost Spins
In the main game you have the option to activate a Boost function for an extra cost of 1.50x the bet.
Boost does three things:
- Enhances the likelihood of triggering the expanding symbol feature in the main game
- Increases the chances of activating Free Spins
- Increases the chances of activating Super Free Spins
That third point matters more than it looks. Super Free Spins can’t be triggered by ordinary scatters in the main game; they only come from boost spins or the Bonus Buy. Boost is therefore the only route to the game’s best round without paying the buy price upfront.
The main-game expansion under Boost behaves exactly as it does in Free Spins, minus the multipliers: three or more of the selected symbol expand, pay anywhere across the grid, and that’s the end of it. The multipliers only exist inside the bonus rounds, which is where Boost is quietly pointing you.
One restriction applies: Bonus Buy can’t be used while Boost mode is active, so the two paths to the bonus are mutually exclusive. You either pay the surcharge on every spin for a shot at either round, or you leave Boost off and keep the buy menu open.
Free Spins and Super Free Spins
Landing three or more scatter books triggers the Free Spins feature, and there are two variants. Normal Free Spins come from scatter triggers in the main game or from the Bonus Buy. Super Free Spins only come from boost spins or the Bonus Buy, and during boost spins the split between the two is a straight 50/50.
The two variants run the same round on different multiplier ladders. The Super round works identically to the Normal one in every other respect: same selection, same expansion, same explosions.
Inside the round, the expanding symbols work as a step-by-step chain:
- Each spin selects a random special symbol
- After regular wins are paid, that symbol may expand to cover all three positions on its reel
- If it expands on three to five reels and produces a payout, the expanded symbols explode and new symbols cascade down
- A new symbol is randomly chosen, and the re-spins continue for free until the expansions stop producing wins
- Each explosion raises the multiplier, which stays active until the Free Spins conclude
That loop is what separates this from the standard book template. A round doesn’t end when the first expansion pays; it can roll through several symbols, several explosions and several multipliers before the reels settle. Every re-spin in the chain is free, so a long run costs nothing extra from the round itself.
The two multiplier ladders step up as follows:
- Normal Free Spins: x1, x3, x4, x6, x8, x10, x15, x20
- Super Free Spins: x1, x6, x8, x10, x15, x20, x50
The gap between those ladders is the real distinction between the rounds. Both climb on the same logic, but Super Free Spins skip the low steps and finish on a x50 ceiling that Normal Free Spins can’t reach. The first rung of the Super ladder already sits at x6, more than halfway up the Normal ladder’s climb.
The multiplier isn’t tied to a single spin, either. It escalates with each explosion and stays live until the Free Spins conclude, so a chain that runs early in the round keeps its raised multiplier for everything that follows.
Bonus Buy
Because there are two Free Spins variants, there are two Bonus Buy options: one for Normal Free Spins and one for Super Free Spins. The Super variant is the only guaranteed route to the higher multiplier ladder, since boost spins offer it at 50/50 odds.
- Normal Free Spins buy: the standard round with the x1 to x20 multiplier ladder
- Super Free Spins buy: the enhanced round with the x1 to x50 ladder
The choice between them is the whole decision: the Normal buy delivers the same round a scatter trigger would, while the Super buy skips the coin flip that boost spins impose. Neither purchase is available with Boost switched on, so the surcharge route and the outright purchase never overlap.
Our Honest Verdict
Overall Rating: 7.7/10
Playing Book of Rrrum is a cheerful ten-liner with a pirate’s patience: most spins are plain sailing, and the reason to come aboard is that rare round where the expansions start exploding and don’t stop. A bonus that pays, rebuilds and pays again is a genuinely different experience from the one-hit book format.
The strength is the carried multiplier. Because it survives each explosion and holds until the round ends, an early chain makes everything after it worth more, so a good round compounds instead of tapering. The weakness is the gate on the best version: Super Free Spins never come from plain scatters, so the x50 ladder only opens through a 1.50x surcharge on every spin or the buy menu, and the two routes can’t be combined.
It suits players who enjoy the book format but want the feature to keep working once it lands. Anyone after a simple, single-payout expansion will find the extra layers busier than they fancy. There’s real treasure on this voyage; you just have to be willing to pay for the deeper dive.
Book of Rrrum FAQs
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What is the RTP of Book of Rrrum?
Book of Rrrum runs at an RTP of 96%. -
Is Book of Rrrum high volatility?
Book of Rrrum sits at mid-to-high volatility, so wins can be spaced out with the larger payouts concentrated in the Free Spins rounds. -
How do the Free Spins trigger in Book of Rrrum?
Landing three or more scatter symbols, which are the books, triggers Free Spins. Two scatters on their own pay 2x the bet. -
How do you get Super Free Spins in Book of Rrrum?
Super Free Spins can only be obtained from boost spins or through the Bonus Buy. During boost spins there’s a 50/50 chance of receiving either Normal or Super Free Spins. -
What happens when the expanding symbols explode in Book of Rrrum?
When the selected symbols expand on three to five reels and pay out, they explode and new symbols cascade down. A new symbol is chosen and free re-spins continue until no further wins occur, with the multiplier climbing on each explosion. -
What does the Boost function cost in Book of Rrrum?
Boost costs an extra 1.50x the bet per spin. It improves the odds of the expanding symbol feature and both Free Spins variants, and it can’t be combined with Bonus Buy. -
Can you buy the bonus on Book of Rrrum?
Yes. There are two Bonus Buy options, one for Normal Free Spins and one for Super Free Spins. -
What is the difference between Normal and Super Free Spins in Book of Rrrum?
Both rounds play the same way, but they run on different multiplier ladders. Normal Free Spins climb from x1 to x20, while Super Free Spins climb from x1 to x50 with higher steps along the way. -
How many paylines does Book of Rrrum have?
Book of Rrrum has 10 paylines on a 5×3 grid, and its expanding symbols pay anywhere rather than needing adjacent reels. -
Who makes Book of Rrrum?
Book of Rrrum is made by ESA Gaming. -
When is Book of Rrrum released?
Book of Rrrum’s release date is 23 October 2024.
