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Book of 99 Slot Demo & Review – Play for Free

As the name suggests, Book of 99 promises some of the highest returns in online slots in 2026 (and ever). I’ve played this one countless times over the years, and this time, I’ve put together a guide with my personal strategies for maximising the 99% RTP, a rundown of the rules, and how much each symbol combo pays.

Shannon Hundermark
S.H.

Last updated: 2026-02-10

Chad Nagel

9 minutes read

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Book of 99 Slot Review 2026

Book of 99 Slot Review 2026

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Best SA Casinos for Playing Book of 99

  1. World Sports Betting
  2. Easybet
  3. Tic Tac Bets

I’ve spent a lot of time on World Sports Betting, and as a regular player, I’d describe it as the old reliable of the SA market. It’s not the flashiest site, but it’s practical. For a game like Book of 99, I prefer playing here because there isn’t any lag mid-spin, which is a massive relief when you’re 80 books deep into a collection grind. 

Another reason I keep going back is that I know withdrawing my winnings isn’t going to be a headache. The initial FICA process is straightforward, and my winnings hit my bank account within 24 hours generally. 

As for variety, every major provider I can think of is supported, from slot legends like Pragmatic Play, Habanero, and NetEnt to live casino studios like Ezugi and Evolution

Book of 99 Slot Review

Slot Developer

Relax Gaming are licensed by the MGA and UKGC and audited by eCOGRA, which, in simple terms, means all their games are certified for fairness. In 2024 and 2025, they won EGR B2B Awards and SBC Awards for "Innovation in Slot Provision", which reflects quite accurately the effort they’ve made to bring unique slot features to the market.

Slot Theme and Storyline

Book of 99 is a comic-book-style slot themed around Homer’s Odyssey. There are hand-drawn pictures that feel very "ancient warrior on a mission". The symbols are packed with characters like a battle-hardened king and a creepy one-eyed Cyclops, so I feel like I’m playing to be a part of the story, rather than just looking at a screen. 

Reels, Rows, Paylines

The setup is a 5x3 grid with 10 fixed paylines, where wins are paid out from left to right, starting from the first reel, followed by at least two high-paying or three low-paying symbols.

RTP & Volatility

The 99% RTP is pretty much the main star of the game, as it essentially promises that almost all your wagers will be returned in the long run, with the thin house edge of just 1%. Still, the high volatility isn’t a stroll in the park by any means, so you need to go in with a fairly generous bankroll and patience. 

Betting Range

The betting range is fairly accessible, with starting bets as little as 40c up to R1,000 or more, depending on where you’re playing. 

Max Win Potential

The maximum win is 5,000x your stake, but there’s been a fair bit of hype online with reports of a potential 12,075x payout during the extended free spin retriggers. Essentially, this would require a full screen of Odysseus during the free spins with an active expanding mechanic.

Graphics & Sound

The hero symbols pop nicely against the darker grid tones, but the audio doesn't feel quite as satisfying for me. The soundtrack does a decent job of creating an eerie atmosphere, but I find it lacks the high-energy feel I usually look for, so I just mute during longer sessions. 

Pros and Cons

Pros

  • Features an industry-leading 99% RTP

  • Inclusive betting limits (40c and R1,000)

  • High hit frequency (almost 30%) for high volatility

  • The bonus is retriggerable up to 10 extra spins

Cons

  • Some SA casinos don’t support Bonus Buy 

  • 10 paylines can feel restrictive

Game Symbols and Payouts

Special Symbol

The Book is a “special symbol” with three different roles: 

  1. Wild: Substitutes for all other symbols to help form winning combos.
  2. Collector: Every book that lands in the base game adds +1 to the collection meter on the left. 
  3. Scatter: Triggers the free spins round if you manage to land 3+ anywhere on the grid. It also pays cash if you do use it as a scatter:
    -    5 Books: Rewards 200x your stake
    -    4 Books: Rewards 20x your stake
    -    3 Books: Rewards 2x your stake

Regular Symbols

All the other symbols are split into card ranks, which pay the least, and Greek characters, which pay up to 500x your total stake

Symbol

5 of a Kind

4 of a Kind

3 of a Kind

2 of a Kind

Apollo

500x

100x

10x

1x

Oracle

200x

40x

4x

0.5x

Cyclops / Lamia 

75x

10x

3x

0.5x

A / K

15x

4x

0.5x

-

Q / J / 10

10x

2.5x

0.5x

-

Book of 99 Slot Demo Version and Free Play

I never suggest diving into a high-volatility slot with real money until you’ve taken the demo for a test drive. You can access the free-play version directly on the Relax Gaming website to get a feel for the mechanics. 
It's also a chance to see how the fake bankroll will mimic your actual balance when the time comes. If you plan to deposit R100, treat your demo credits exactly like that and set your stake to R1 or R2 just as you would in a real session. This can tell you how far you’ll get with those inevitable dry spells. 

Book of 99 Slot Bonus and Key Features

Free Spins Triggered With Scatters

The quickest way into the bonus round is with three or more book symbols in a single spin. This will give you 10 free spins and a scatter payout that can reach up to 200x your stake.
You can also retrigger an additional 10 spins with another three books during the round if Lady Luck is on your side. And retriggers are limitless, which is why the industry-accepted 12,075x feature cap is entirely possible.

Free Spins Triggered With Scatters

Free Spins Triggered With Scatters

The 99-Book Collection Meter

The Collection Meter on the left guarantees a bonus trigger when you reach 99 books, but you need to be more patient. In my experience, this feature is more like a nice little surprise when you’re in the depths of a long session and no longer paying attention to the meter, which takes a while to build. 

The 99-Book Collection Meter

The 99-Book Collection Meter

Special Expanding Symbols

The game randomly chooses one regular symbol to act as the special expanding symbol before your free spins kick off. 
This symbol will expand to cover all three positions on its reel when it lands and even pays out like the scatters, so they don't need to be on adjacent reels to win. You just need enough of them anywhere on the board. This is where the 5,000x single-spin potential comes in, but it’s going to require expanding Apollos that fill the entire grid.   

How to Play Book of 99 Slot for Real Money

  1. 1

    Press the coin button at the bottom of your screen and select a stake you’re comfortable with.

    Press the coin button at the bottom of your screen

    Press the coin button at the bottom of your screen 

  2. 2

    Wait for the books to land. 2 or less just add to the collection meter, while 3 or more trigger the bonus round. 

    Wait for the books to land.

    Wait for the books to land.

  3. 3

    Start spinning manually with the large spin button or set up an autoplay run of up to 1,000 spins with a stop-limit to protect your profits later on.

    Start spinning manually with the large spin button

    Start spinning manually with the large spin button 

  4. 4

    Once you land 3+ scatters, your expanding symbol is selected randomly and presented to you before the round starts. 

    Once you land 3+ scatters

    Once you land 3+ scatters

Mobile Play Experience

Mobile Play Experience book of 99

Mobile Play Experience book of 99

I usually play Book of 99 on my phone and appreciate that Relax Gaming lets regulars like me skip the splash screen and intro movie in the settings to cut down on loading times. 
What I love most, though, is how much I can customise the actual vibe of the session. The game has separate toggles for sound effects and music, so I prefer to mute the repetitive music and keep the SFX on so I can still hear the clink when I land a win while I listen to music on another app. 

Book of 99 Expert Tips & Strategies for Winning

  1. Never set your stake higher than 1% of your total balance. If you have R500 in your account, stick to R5 spins (or lower). Without that breathing room to weather the dry spells, you might as well give your money away on account of the high volatility, which essentially promises long dry spells before you actually land a worthwhile win.  

  2. The 99-book collection meter is tied to your specific bet level, so you can’t just jump from a R2 stake to a R10 stake without starting a brand new meter. Just pick one bet size and stay with it until you hit the 99-book guarantee so you don’t lose all the progress you’ve made.

  3. The misses can become tedious, so you’re probably going to use autoplay at some point. Just make sure you also set up an automated loss limit in the settings so you don’t get caught up in the 99-book chase and overspend.

Book of 99 Slot Alternatives

  1. Book of Dead by Play’n GO: The 96.21% RTP is lower than Book of 99, but it’s still well above the industry average, and the gameplay is virtually identical, with single expanding symbols during free spins. 
  2. Legacy of Dead by Play’n GO: The standout feature here is that the game awards an additional expanding symbol every time you retrigger the bonus. There’s also no limit on expanding symbols, so you can essentially end up with all 9 symbols expanding on every spin.
  3. Marching Legions by Relax Gaming: Also features a generous RTP of 98.12% for the highest version, but swaps the book mechanic for marching re-spins and a similar collection feel to Book of 99, but with a tactical twist.
     

SportsBoom Suggests – Is the Book of 99 Worth Playing?

I’d be hard-pressed to find a solid reason not to recommend Book of 99. It’s one of the most strategic options if you’re sticking around for long sessions due to its massive 99% RTP and the collection meter’s feature guarantee.

But it’s probably best to stay clear if you’re coming in with a tiny bankroll that can’t accommodate at least 150 spins on the lowest stake level, because you’re probably going to wipe out before you get a solid win in.

FAQs

What is its RTP and volatility?

The RTP is a massive 99%, which is quite remarkable in an industry where 96% is considered decent returns. The volatility is rated as high, so you’ll probably experience a cold streak where nothing happens and a couple of major wins in between if you bet smart.

What’s the max win potential?

The max win in the base game is 5,000x your stake, and the max feature win is widely reported to be 12,075x (only possible if you land enough expanded Apollas to fill the screen during the free spins).

How do the bonus features work?

You can get into the free spins round in 2 ways: landing 3 scatters on a single spin anywhere or collecting 99 books in the collection meter. Once you’re in, a random symbol is selected and expands to fill the entire reel every time it lands.  

Any special tips for SA players?

Establish your betting strategy before you start spinning and stick to it, because changing your stake level mid-game resets the collection metre, which means you’ll lose all the progress you’ve made towards unlocking the guaranteed feature.

Shannon Hundermark
Shannon Hundermark Casino & Sports Writer

Shannon Hundermark is an iGaming and sports writer focused on creating genuinely valuable content. Published on Business2Community and Gamblingsites.com, Shannon draws on personal experience to deliver objective, well-researched reviews and guides, with the intention of helping real players worldwide make informed decisions.