Quick answer
Book of 99 is a Relax Gaming slot (2021) with 99% RTP, very high volatility and a 12,075x max win. It uses 10 paylines with free spins. An official free demo is available. RTP can vary by casino.
Key specs
- RTP
- 99%
- Volatility
- Very high
- Hit frequency
- 29.83% (about 1 in 3.4 spins)
- Max win
- 12,075x
- Grid
- 5 reels
- Pays
- 10 paylines
- Released
- 4 May 2021
- Bet range
- $0.10–$100
- Jackpot
- None
Casinos with Relax Gaming games
- Aurivo Casino100% up to $1,000 + 200 Free Spins30x bonusCarries Relax GamingPlay at Aurivo Casino (opens in new tab)
18+. New customers. Min dep $20. 30x bonus wagering. Max bet $5. 30 days. 200 spins on Book of Dead at $0.20. Credited in daily batches of 20 over 10 days. Full T&Cs apply.
Key terms
18+. New customers only. Min deposit $20. 30x bonus wagering requirement. Max bet $5 while wagering. Free spins on Book of Dead at $0.20 per spin. Spins credited in daily batches of 20 over 10 days. Offer valid 30 days. Full T&Cs apply. Please gamble responsibly.
Check Book of 99 is in the lobby in your country.
Themes:
Free demo Members
Try Book of 99 with play money before deciding whether to play for real. Official Relax Gaming demos are free for GambGenius members.
How to play Book of 99 (members only)
Wins are paid when matching symbols land on an active payline, usually left to right starting from the leftmost reel. Your total stake is spread across the lines, and each line win is the line bet multiplied by the symbol's paytable value.
Book of 99 is played on a 5 reels grid with 10 paylines.
- Set your stake. Choose your total bet per spin between $0.10 and $100. Wins are paid as multiples of this stake.
- Check the paytable. Open the game's info screen to see what each symbol pays and the exact rules for this version.
- Spin. Each spin's result is decided by a certified random number generator, independent of previous spins.
- Trigger the bonus. Land the required scatter symbols to start the free spins feature.
The full Book of 99 guide: how winnings work, 1 feature and 3 strategy tips
- Your stake plan: a $50 budget → about $0.12 a spin (very high volatility)
- What 99% RTP costs per $100 wagered: $1.00 on average
- 1 feature explained: free spins
- Stake plans for $20 to $250 budgets, checked against the $0.10 minimum bet
- Strategy tips and a session planner for Book of 99
Free · no card · 18+ only
Never sold · export or delete any time · What do members get?
How winnings work (members only)
What 99% RTP costs per $100 wagered, the 12,075x max win at a $1 stake
The top prize is capped at 12,075x your stake. On a $1 spin that is $12,075; on $0.20 it is $2,415. When the cap is reached the round usually ends immediately.
What 99% RTP means
Expected return = stake × 99%
Over $100 of total bets, the long-run average loss is $1.00
RTP is a long-run average across millions of spins. Any single session can finish far above or below it, especially on a very high volatility game.
The published hit frequency is 29.83%, meaning roughly one spin in 3.4 returns something — though many of those wins are smaller than the stake.
Features explained (members only)
1 feature explained: free spins
Free spins
A bonus round of spins played at no cost to your balance, usually triggered by landing three or more scatter symbols. Wins during the round are added to your balance, and many games let you retrigger extra spins.
Strategy tips (members only)
- Size your stake to the volatility. Very high volatility means most spins lose and a large share of the return comes from rare big features. Treat it as entertainment with a strict budget and a stake of around 0.5% of your session budget or less. A simple rule: bring at least 400 spins' worth of budget, so a $50 budget suggests a stake of about $0.12.
2 more tips and a session planner
- Bonus wagering: at 99% RTP, clearing $1,000 of wagering costs about $10.00 on average. Check the bonus terms, as some casinos exclude specific games. Run your numbers in the wagering calculator.
- Set limits before you spin. Decide your loss limit and session time in advance and stop when you reach either. No pattern or betting system changes the outcome of a spin.
More on this in slot RTP and volatility explained and bankroll management.
Does it fit your budget? (members only)
Stake plans for $20 to $250 budgets, checked against the $0.10 minimum bet
For very high volatility we suggest a budget of at least 400 spins. This is what that means for Book of 99 (bets from $0.10 up to a maximum bet of $100).
| Budget | Stake a spin | Bet range | Average cost of 400 spins |
|---|---|---|---|
| $20 | $0.05 | Below the $0.10 minimum bet | $0.20 |
| $50 | $0.12 | Fits | $0.50 |
| $100 | $0.25 | Fits | $1 |
| $250 | $0.62 | Fits | $2.50 |
Averages only: a short session can end far above or below them. Set a loss limit before you play.
Questions
Frequently asked questions
Who makes Book of 99?
Book of 99 is developed by Relax Gaming and was released in 2021.
What is the RTP of Book of 99?
The default RTP of Book of 99 is 99%.
Is Book of 99 high volatility?
Book of 99 is rated very high volatility. Very high volatility means most spins lose and a large share of the return comes from rare big features.
What is the max win on Book of 99?
The maximum win on Book of 99 is 12,075x your stake, which is $12,075 on a $1 spin.
Can I play Book of 99 for free?
Yes. GambGenius members can play the official Relax Gaming demo of Book of 99 free on this page. It uses play money only, so demo wins can't be withdrawn, and it is for players aged 18 and over.
Does Book of 99 have a bonus buy?
No bonus buy is listed for Book of 99 in the sources we checked.
Where can I play Book of 99?
Aurivo Casino carries Relax Gaming games. Check Book of 99 is in the lobby in your country before you sign up. 18+ · New customers · T&Cs apply. Availability varies by country.
Where this data comes from
- relax-gaming.com Provider
- bigwinboard.com Slot database
Specs come from the provider's own site and 1 independent slot database. Casinos can run lower-RTP versions, so always check the game rules before you play.
Game artwork © Relax Gaming, shown to identify the game.
