Book of 99 Slot Review: Discover the Stunning RTP & Gameplay

Battle amongst the Gods and make your mark on history in Relax Gaming’s first-of-its-kind 99% RTP release, Book of 99. This Greek-inspired slot makes use of a traditional 5×3 reel layout with 10 fixed paylines to offer you the chance of landing wins worth up to 5,000x your stake.

As if its maximum win potential wasn’t enough, free spins also come with special expanding symbols and there’s more than one way to trigger this impressive bonus.

So, if you’re looking for the next big ‘Book of’ slot, you can check out the game’s key features below before diving into our full Book of 99 slot review.

  • Reels: 5
  • Rows: 3
  • Paylines: 10
  • RTP: 99.00%
  • Volatility: Very High
  • Max Win: 5,000x
  • Features: Wilds, Expanding Symbols, Free Spins, Collection Feature

Book of 99 Features

‘Book of’ slots traditionally incorporate recognisable and straightforward features. Their simplicity often helps to attract a wider player base and we can’t see any reasons why Relax Gaming’s latest release will struggle to captivate its audience. Wilds, free spins, expanding symbols and a Collection Feature all help to make your session that much more enjoyable.

Scatter/Wild Symbol

The Book symbol serves both as the game’s Wild and the Scatter. First of all, It substitutes for all other paytable symbols to help form winning combinations thus increasing your chances of a payout. Second, it’s Book of 99’s all-important Scatter symbol. When 3 land during a base game spin, you’ll trigger the main free spins feature.

However, it also has another role to play; it’s a key component of the Collection Feature, which we go on to describe below.

Collection Feature

The Collection Feature adds a somewhat unorthodox element to the overall gameplay. Each Wild increases the collection meter by 1 step and upon reaching 99 collected Wilds, the free spins feature automatically triggers. It’s an interesting inclusion that offers players another route to free spins should the regular Scatter trigger not occur.

Book of 99 Free Spins and Bonus

No ‘Book of’ slot would be complete without a free spins bonus and Book of 99 doesn’t disappoint. The main feature will trigger whenever either 3 Book symbols land during a single spin or when the Collection Meter is full.

Upon activation, you’ll receive 10 free spins. Before the bonus begins, a randomly selected special expanding symbol is awarded.

On each free spin, special symbols expand to cover each position on their respective reel. These do not need to land on an active payline, nor do they need to land on adjacent reels; expanding symbol wins are awarded irrespective of their position on the reels.

Finally, you can retrigger free spins by landing 3 additional Book symbols during a single spin. This awards +10 free spins to your remaining total.

Book of 99 Theme and Symbols

It’s not until you load Book of 99 that any sort of theme reveals itself – it isn’t as though the name gives anything anyway. What you’ll see is a background with a resemblance to Greek architecture and several symbols that help to establish the overall aesthetic. It seems that Relax Gaming has opted to place greater focus on the game’s staggering RTP and features as opposed to its overall design.

Symbol-wise, there’s nothing out of the ordinary. Low-value wins are depicted by traditional 10-A royals, whilst much more profitable payouts are available via the 4 high-paying character symbols – as much as 500x your stake for 5 of the game’s premium.

Book of 99 RTP and Volatility

Book of 99 is classified as a highly volatile online slot, with Relaxing Gaming rating it 5/5 on their variance scale. However, you shouldn’t necessarily let that put you off. Where this slot truly stands out in terms of its math model is as a result of its astonishing 99% RTP. When most online slots offer somewhere in the region of 96%, Book of 99 overwhelmingly rises above its competition with regards to its payout potential.

How To Play Book of 99

Another area where Book of 99 pleases relates to its simplicity. The gameplay is straightforward and avoids the potential pitfalls of convoluted bonus and pay mechanics.

The slot operates similarly to its 5×3 layout predecessors, so you needn’t spend too much time looking at the information panel. However, all of the game’s functions are conveniently located beneath the reels should you wish to make any betting adjustments or brush up on the rules. 

Stakes range from the €0.10 minimum bet to the €100 maximum bet.

Slotsia’s Review

Traditionally, ‘Book of’ slots don’t tend to have as much of a draw as more innovative releases. That being said, we feel as though Book of 99 could be the exception to the rule. Although it’s unlikely to win any awards for its visuals, the combination of impressive features along with its incredible 99% RTP is surely going to attract plenty of positive attention.

The Collection Meter is another nice touch, too. It gives players an attainable goal that results in guaranteed free spins. So, even if you don’t manage a natural activation, you have an alternate route to huge potential wins.

Pros and cons:

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Remarkable 99% RTP

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5,000x max. win

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Two ways to trigger free spins

High volatility