Bonus Buy or earned feature?

Two ways to trigger it. No documented buy button.

The published game rules describe the two entries below. Neither is a promise that a chosen budget will reach the feature.

One base-game spin

3+ Book wilds

Initial award
10 Free Spins
Feature stake
The stake of the triggering spin
What to watch
Books can land anywhere; they need not share a payline.
Collected across base-game spins

99 Book wilds

Initial award
10 Free Spins
Feature stake
The weighted average attached to the collected Books
What to watch
A losing spin can still add Books. The counter is not a countdown in spins.

Work through the collection stake calculation →

Book of 99 Free Spins help showing expanded giant symbols

Entry rule

Three Books now—or ninety-nine over time.

Landing three or more Book wilds anywhere awards ten Free Spins at the stake used for that spin. Completing the collection also awards ten, but the stake is derived from the collection history.

VerifiedThe feature can retrigger: three or more Books during Free Spins add another ten spins.

What happens next

01

The game chooses

One of the nine regular symbols becomes the special expanding symbol for the whole feature.

02

Normal wins settle

Each free spin first evaluates ordinary line wins, with the Book still acting as wild.

03

Expansion checks

Two matching high symbols or three matching low symbols can qualify the special symbol to expand.

04

All lines are read

Reels containing the selected symbol expand; the special payout can use all ten lines without the normal adjacency rule.

Try the expanding symbol

Turn matching symbols into full reels

Tap the grid to place the chosen feature symbol. Hit the required number and every reel carrying a match expands before the ten paylines are counted.

Activation rule2+ high-pay symbolsExpansion can pay on all 10 lines, even without a normal left-to-right connection.
Matches3
Reels affected3
What happensExpansion active

This hands-on example shows how expansion works; it does not recreate or predict real spins.

+10

Retrigger rule

Books remain active during the feature.

Landing three or more Book symbols anywhere during Free Spins adds another ten spins. One or two Books do not add spins, and the randomly selected expanding symbol stays the same for the retriggered spins.

Randomly chosenYou cannot choose the expanding symbol.
Not a multiplierExpansion uses the selected symbol’s paytable values.
Not a guaranteeA ten-spin feature can still return less than the triggering stake.

Player questions

Book of 99 bonus questions

01Does Book of 99 have a Bonus Buy?

The published Book of 99 rules describe two ways to start Free Spins: land three or more Books on a base-game spin, or collect 99 Books. They do not document a paid Bonus Buy. Check the help in the version you load; a casino promotion is not a third game trigger.

Inspect the feature in the demo
02Are the Free Spins the same as a casino welcome bonus?

No. The game feature is awarded by the reels or collection counter. Promotional spins come from a separate casino offer and can have eligibility, expiry, game restrictions and withdrawal conditions. A Book of 99 feature does not automatically mean you qualify for a promotion.

See how a normal round works
03Can I choose the expanding symbol or pay to change it?

The game selects the expanding symbol at random. The documented rules do not offer a paid symbol choice. During a retrigger, the selected symbol remains the same.

Compare the collection stake rule
Next chapterHow the 99-Book stake average works →