Book of 99

Game rules

"Book of 99" is a 5 columns and 3 rows slot machine with 10 pay lines. The game is always played with all pay lines active.

The theoretical return to player for this game is 99.00%.

Winning combinations and payouts are made according to the paytable.

Only the highest paying combination for each payline is paid.

Wins are evaluated consecutively on a payline, starting from leftmost reel.

Wins on multiple paylines are added.

The wild symbol substitutes for all symbols except the special expanding symbol in Free Spins.


A collection meter exists, which starts at 0 and goes to 99.

For every Wild symbol that appears in the main game, the collection meter is increased by 1.

Free Spins can be triggered in two ways, either by landing 3 or more Wild symbols anywhere during a spin, or by collecting enough Wild symbols for the collection to be completed.

When triggering Free Spins through collection, the bet size used is the weighted average of the bet sizes used when collecting each Wild. When triggering Free Spins through landing 3 or more Wild

symbols, the Free Spins are played at the bet size used in the triggering spin.

The average bet size must be an integer multiple of the minimum bet. If it is not, it is rounded according to the rules of stochastic rounding (e.g. if the average becomes 1.2 times the minimum bet,

with a 20% probability it will be rounded to 2 times the minimum bet and with 80% probability it will be rounded to 1 times the minimum bet).

After collecting 99 wild symbols and the Free Spins have been awarded, the collection meter is reset to 0.

If collecting more wild symbols than 99 and the Free Spins have been awarded, the collection meter will be reset to include the remaining wild symbols (e.g. if collecting 101 wild symbols, the collection meter will be reset to 2).

When simultaneously landing 3 or more Wild symbols and completing the collection in the same spin, first the Wild triggered Free Spins are played, followed by the collection triggered Free Spins.

Free Spins

When triggering Free Spins, 10 spins are awarded.

One of the 9 regular symbols is randomly chosen to be the special symbol for the duration of Free Spins.

For each spin, any normal wins are paid out first. Then, if there are enough of the special symbols (2 for high paying symbols and 3 for low paying symbols), they expand to cover the whole reel and pay out for each of 10 lines, regardless of their horizontal position, according to the number of symbols and the corresponding pay table value. Note that any existing wild symbols are disregarded for the expanded special symbol payout.

3 or more Wild symbols appearing anywhere in a spin awards an additional 10 spins.


Select a bet size, then press the Spin button to begin.

To use autoplay, press the Autoplay button and select the desired number of rounds.

Autoplay is started and stopped by clicking the autoplay icon where applicable.

While playing, you can always see how many autoplay spins you have left.

Press the "Home" icon to exit game.

Winnings are presented in the user's currency.

Malfunction voids all pays and plays.

Once a spin has been initiated the bet-level for that round is locked and cannot be changed.

Incomplete games will be automatically resolved after 2 days. Any winnings resulting from automatic resolve shall be paid to player's account.

If your balance decreases so it becomes lower than the selected bet size, the bet size will automatically be lowered to the highest applicable bet size

Last modification date: 1/9/2024