Book of 99 Slot Game: A Complete Review of Its Theme, Features, and Gameplay Experience
Book of 99 is a highly volatile online casino slot launched in 2021 by Relax Gaming. It has one of the highest RTP ratings in the online gambling industry, standing at 99%! With quality graphics, sound effects, and a free spins feature, it offers you the best slot gaming experience set in ancient Greece.
Theme of Book of 99
Book of 99 revolves around ancient Greek mythology. The background features the Greek countryside in dark lighting, which changes to daytime scenery if you’re in the free spins round.
The slot’s grid is set on a concrete structure mimicking ancient Greek architecture. The counter for the collection feature on the left of the grid is particularly interesting. You’ll find a boat sailing through a map as you collect more and more book symbols. The game grid has five reels and three rows where different mythological characters, the book symbol, and card icons appear.
Music and Sound Design
Book of 99 comes with upbeat background music and a nice melody that gives you an old civilisation vibe. Each of the four characters has their own voice playing in the background when you make a winning combo with them. The book symbol also has its own winning sound. You can listen to a royal celebratory tune when you win big amounts by matching expanding symbols.
Symbols and Payouts
The Book of 99 has a total of 10 symbols, including five high-paying ones and five low-paying ones. The high-paying ones are the book, Apollo, Pythia, Polyphemus, and Lamia. The low-paying symbols are A, K, Q, J, and 10.
There are 10 fixed paylines on the slot with a maximum winning potential of 5,000x your bet. To form a winning combo, you need to line up at least two character symbols or three low-paying ones. The book is a wild symbol that can act as a substitute for all symbols except for the specific expanding symbol in the free spins round.
The paytable for one line with the minimum bet of 0.10 coins:
| Symbol Name | 5 of a kind | 4 of a kind | 3 of a kind | 2 of a kind |
| Apollo | 50 | 10 | 1 | 0.1 |
| Pythia | 20 | 4 | 0.4 | 0.05 |
| Polyphemus | 7.5 | 1 | .3 | 0.05 |
| Lamia | 7.5 | 1 | .3 | 0.05 |
| A | 1.5 | 0.4 | 0.05 | – |
| K | 1.5 | 0.4 | 0.05 | – |
| Q | 1 | 0.25 | 0.05 | – |
| J | 1 | 0.25 | 0.05 | – |
| 10 | 1 | 0.25 | 0.05 | – |
The paytable for one line with the maximum bet of 100 coins:
| Symbol Name | 5 of a kind | 4 of a kind | 3 of a kind | 2 of a kind |
| Apollo | 50,000 | 10,000 | 1,000 | 100 |
| Pythia | 20,000 | 4,000 | 400 | 50 |
| Polyphemus | 7500 | 1000 | 300 | 50 |
| Lamia | 7500 | 1000 | 300 | 50 |
| A | 1500 | 400 | 50 | – |
| K | 1500 | 400 | 50 | – |
| Q | 1000 | 250 | 50 | – |
| J | 1000 | 250 | 50 | – |
| 10 | 1000 | 250 | 50 | – |
Bonuses and Special Features
Book of 99 is not very big on bonus features. There’s only one special feature, the free spins round, but it has the potential for large payouts. To trigger the free spins mode, you need to land three or more wild symbols. Another way of triggering free spins is with the collection mechanism. With each book symbol you land during the base game will increase the collection meter by one. When you collect 99 wild book symbols, you trigger the free spins mode.
The game will then offer 10 free spins with a random symbol set as the expanding symbol for that round.
Depending on the random symbols chosen, landing two or more expanding symbols during free spins will trigger them to expand and fill the reels they appear on. This will pay out on all 10 paylines and the winnings will depend on how many expanding symbols you land. The amount you win will correspond to the paytable values. The expanding symbol will pay both ways on every line, even when they are not connected from left to right.
Pros and Cons of Book of 99
Pros:
- Very high RTP
- Offers a unique collection feature
- Free spin feature with expanding symbols
Cons:
- High volatility means less frequent wins
- Limited variety in bonus features
Popularity and Reception
Though several “Book of” games are out there, Book of 99 has a couple of exceptional features that contributed to its popularity. We’ve seen many players praise the slot for its very high RTP and immersive theme. The bonus features are short in supply, but the collection feature attracts many players because when the book symbol randomly appears and doesn’t pay out, it still has a purpose. High rollers praise the high volatility as larger bets can offer large winnings with better chances of triggering the free spins feature.
On the flip side, we’ve seen some players complain that the game sometimes freezes. However, that’s true for any slot game as they can run into network issues and memory overloads. Other complaints include the rarity of five-of-a-kind wins, which is, again, true for all slot games out there.
RTP (Return to Player)
Book of 99, as the name suggests, has a very high RTP of 99%. This is only the theoretical measure that indicates that, over the long run, you will get almost 99 cents for every dollar you wager. It is calculated by simulating over thousands of spins, so getting to that point of 99% return is very time-consuming. This means, in the short run you can’t expect that high a return. Plus, the high volatility could induce a dry spell, or it could give you a very high return if you’re really lucky.
Final Opinion on Book of 99
Even though Book of 99 may look like just another game in the “Book of” genre, it offers a unique experience with a Greek theme and exciting symbols. Many aspects make this game appealing: the high RTP makes it too attractive not to try; the collection and free spins features can provide you with big real-money winnings; the visuals and sound effects are also very immersive for all kinds of players.
Available to play on Betswap.gg, we’d highly recommend giving it a go!