Book of 99
99%
RTP
12,075x
Max Win
- Reels
- 5
- Rows
- 3
- Paylines (up to)
- 10
- Min Bet
- 0.1
- Max Bet
- 100
- Release Date
- May 4, 2021
About this Slot
Book of 99 is a Greek-themed slot with 5 reels, 3 rows and 10 paylines. The game offers an RTP of 99% with high volatility and a maximum win of 12,075x stake.
The game features cascading mechanics, where winning combinations remove symbols from the reels to allow new symbols to fall into their place. Each cascade can form additional winning combinations in a single spin.
Wild symbols substitute for other symbols to complete winning combinations and also fill a collection meter. When the collection meter reaches full, the game triggers free spins automatically. Free spins can also be triggered directly by landing three wild symbols on the reels.
During free spins, one symbol is designated to expand. This expanding symbol can grow to cover entire reels, potentially creating larger winning combinations across multiple positions. Free spins can retrigger with no upper limit on the total number of spins that can be awarded, allowing the feature to continue indefinitely.
Accumulating ninety-nine wilds during gameplay will trigger free spins, providing an additional path to enter the bonus round.
Book of 99 Demo - Play for Free
The Book of 99 demo runs right here in your browser: play money, no sign-up, no deposit. It comes from Relax Gaming themselves and carries the same rules and features as the real-money version. The stated RTP is 99%.
The demo starts only when you press it. It then loads straight from Relax Gaming, which receives your IP address in the process. More on this in our Privacy Policy.
Play money, no payouts. Providers block the demo in some countries.
Book of 99 Community RTP
Real RTP estimated from rounds contributed by the community, across all uploaders.
Not enough contributed rounds yet for a reliable community RTP estimate.
At least 24,723 more rounds until this slot has a reliable RTP measurement.
Book of 99 RTP Calculator
Book of 99 has a theoretical RTP of 99%. Its volatility is High, so expect long dry spells punctuated by rare, large multipliers. Its win potential is capped at 12,075x your stake. Use the calculator below to estimate your expected return, variance range and risk of ruin over any number of spins.
Book of 99 Variance Simulator
Book of 99 sessions can swing far from its 99% average - its volatility is rated High. The simulator runs many virtual bankroll runs to estimate the bust rate, typical drawdown and best/worst outcomes over a set number of spins - compare a cautious bankroll against an aggressive one.
All Wins
No wins on this slot yet.
Play on Stake*
Frequently asked questions about Book of 99
An RTP of 99% means Book of 99 is built to pay back around 99 for every 100 wagered over millions of spins. Any single session can land far above or below that - use the RTP calculator on this page to model your own bet size and spin count.
Over the long run Book of 99's house edge is about 1% of everything you wager - roughly 1 lost per 100 staked. Short sessions vary widely; the calculator above shows the expected loss and variance range for your inputs.
Quite a lot. Because wins cluster around rare big hits, your balance can move far from the 99% average in either direction. The variance simulator above shows typical drawdowns, bust rate and best/worst outcomes for your bankroll.
It depends on your bet size and how long you want to play Book of 99. Use the variance simulator above to test a cautious versus an aggressive bankroll and see how often each survives your target number of spins.
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