Book of Inferno

About the game

Book of Inferno is a 10-line game with expanding pay anywhere symbols. A symbol is Marked to expand and pay anywhere. Any Book landing will upgrade the Marked symbol one step. A symbol is always Marked at the start of Free Spins. A symbol can become Marked at random in any spin in the base game.

Theoretical payout is 94.19%.

Special symbols

Book Symbols

Book symbols substitute for all other symbols.

3 or more Books award Free Spins.

All the reels can have Book symbols.

Game Features

Marked Symbol

Sometimes, a random symbol will be selected as the Marked symbol.

Any time a Marked symbol lands, if there are enough of them to pay: the Marked symbols are expanded to cover their entire reel and pay anywhere on a line without the need to be in sequence from left to right in an extra win evaluation.

Any Book symbol that lands together with Marked symbols upgrades the Marked symbols one step, potentially creating new Marked symbols and new expansions.

If the Marked symbol is upgraded past the highest symbol, the lowest symbol that has not yet been converted will be converted into the highest symbol.

Base Game

In any spin there is a chance a random symbol will become Marked.

Free Spins

3 Book symbols will award 10 Free Spins and X2 bet win.

4 Book symbols will award 15 Free Spins and X20 bet win.

5 Book symbols will award 25 Free Spins and X200 bet win.

You can re-trigger Free Spins by landing 3+ Book symbols and this awards the same amount of Free Spins as stated above.

At the start of Free Spins, a random symbol is selected as the Marked symbol for that session.

The marked symbol can be updated by landing Book symbols. At the start of each spin, the Marked symbol is reset to the initial symbol.

3 or more Book symbols will award new Free Spins as well as upgrade the Marked symbol.

The Free Spins feature continues until there are no Free Spins left.

Buy Feature

  • You can buy entry into the Free Spins.
  • By paying 125x bet the feature will trigger with 3 or more Book symbols with the same frequency as when triggering it by chance.
  • Free Spins work the same as when triggering by chance.
  • The payout for the Buy Feature is 94.69%.
  • Buy Feature may not be available in all markets.

How to Play

Video slots are very easy to play. Just follow the 3 steps:

  1. Choose your total bet
  2. Press the SPIN symbol button
  3. Check for any win in the WIN field

For more understanding of Settings, Game Rules, and Game Features read the text below.

Description Of Game Functionality


The Total bet is shown in the TOTAL BET display. Change the bet by clicking on the display and choosing the total bet of your choice.


The game is started by pressing the SPIN symbol button.

While the reels are spinning, you can quick stop the game by pressing the screen (where available).


Any total win in a game round will be displayed in the WIN field.

Symbol pays are displayed in the paytable, and reflects the current bet configuration.

Bet line wins pay in succession from leftmost to right.

Only the highest win per bet line is paid.

The separate bet line wins will be displayed on the bet line wins during the win presentation.

In Free Spins only the total win for each spin is shown in the WIN field while the accumulating win for all Free Spins is shown in the TOTAL WIN field.


All winning combinations in the game can be viewed in the paytable, which can be reached through the 'i' button in the keypad menu.


Using Autoplay will let you play a number of game rounds automatically.

Press AUTOPLAY and choose a number of game rounds to initiate Autoplay.

The remaining number of spins is displayed while Autoplay is active.

Autoplay is stopped by pressing the STOP button.

Advanced Autoplay Settings (where available)

The Advanced Autoplay settings allow the player to set number of plays, total session loss limit, and single win limit.

Autoplay will stop when any of the selected limits are exceeded.

Fast Play (where available)

The Fast Play functionality is used to get the shortest game round possible.

Fast Play is initiated from the button in the keypad.

Desktop Version Settings (where available)

In the settings panel at the lower left of the game you can choose:


This setting allows you to choose if the game should play sounds and music.

Use SPACE for spin

This setting allows you to use your Space Bar on your keyboard to initiate game rounds.

Show Splash Screen on start up

This setting allows you to switch the games Splash Screen on and off.

Mobile Version Settings

Player Controls

HOME symbol redirects back to the mobile game lobby.

GAME CONTROLS are reached by tapping the GAME CONTROLS icon.

Game Controls

Access GAME CONTROLS to change TOTAL BET size and access the AUTOPLAY settings.

On the side panel access CLIENT SETTINGS by tapping the SETTINGS ICON.

In SETTINGS, SOUND selection allows you to choose if the game should play sounds and music.

In SETTINGS, REPLAY will take you to game play history.

PAYTABLE icon accesses game PAYTABLE.

The '?' Symbol opens GAME RULES.


Malfunction voids all pays and plays.

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

Last modification date: 2/8/2023