Book of 99 (Relax Gaming) – Review & Demo Play

Book of 99 - Slot Overview

Book of 99 pairs the classic 'book of' template with an Ancient Greece setting. The action plays on 5 reels and 10 fixed paylines, with wagers from 10p up to £100. It's a highly volatile instalment from Relax Gaming, and it looks tidy, with cartoon-styled heroes and beasts backed by a pulsing soundtrack. The base game feels straight to the point, while the bonus screen shifts to a brighter Greek vista that keeps the theme consistent without overcomplicating the format.

Wins start from reel 1 and pay left to right. For the royals 10 to A you need at least three, while the character symbols can pay from two of a kind. Land five of a premium for 75x to 500x your stake, and that's where the full-screen dreams come from. The headline stat is the 99% RTP, which bucks the recent trend and makes this a standout pick in the category, even before you factor in the collection twist in the feature set.

Symbols and Paytable in Book of 99

The paytable keeps things familiar. Lows are 10, J, Q, K, A, paying 0.5x to 15x for five of a kind. Premiums are Lamia, Cyclops, Pythia, and the male lead (Apollo), paying from two matched. Lines of five award 75x, 75x, 200x, and 500x respectively, with intermediate hits at 0.5x to 100x along the way. The Book serves double duty as wild and scatter, substituting for pays and triggering features, so it's the one symbol I'm always tracking across base play and bonuses.

Book of 99 Symbols and Paytable

Symbol	Quantity	Payout
	Scatter, Wild
	5	x500
	4	x100
	3	x10
	2	x1
	5	x200
	4	x40
	3	x4
	2	x0.5
	5	x75
	4	x10
	3	x3
	2	x0.5
	5	x75
	4	x10
	3	x3
	2	x0.5
	5	x15
	4	x4
	3	x0.5
	5	x15
	4	x4
	3	x0.5
	5	x10
	4	x2.5
	3	x0.5
	5	x10
	4	x2.5
	3	x0.5
	5	x10
	4	x2.5
	3	x0.5

Bonus Features in Book of 99

Book fans will know the drill. Land three or more books to get 10 free spins; there's no scatter pay attached. Before the round starts, one pay symbol is chosen to become the special expanding symbol. After any regular wins, all instances of that symbol expand to cover their reels and they pay from any reel, so adjacency is not required. Hit three books during the feature and you'll retrigger for more spins under the same rules.

The twist sits in the Wild Collection meter. Every book that lands in the base game fills one step on a side meter. Reach 99 collected wilds and you're awarded 10 free spins, identical to the standard trigger with the expanding symbol mechanic in play. I like this as a backstop during long spells without a natural bonus, as progress never feels wasted and the eventual trigger mirrors the best bits of the genre with a small added sense of momentum.

RTP, Volatility and Max Win in Book of 99

The headline number is the 99% RTP, which translates to a 1% house edge and places Book of 99 well above the average range. Volatility is rated high, so sessions can swing, but the ceiling is strong at 12,075x your stake. Bets span 10p to £100, and the 10-line set-up keeps the maths tight. In practice, I treat it as a long-run grinder with bursts of excitement when the expanding symbol lands kindly, especially on those premium character picks.

How to Play Book of 99

I start with the free demo to get a feel for pacing and payouts. Set your stake, toggle quick spin if you like, and let 100 auto spins run to spot key patterns such as wins from left to right, premiums paying from two, and how often books show. This game is about patience, so a dry spell in the base isn't unusual. The moment the book pops in clusters, you'll see how wild substitutions prop up lines while you chase the feature.

Next, dial in stakes between 10p and £100 to suit your bankroll, and keep an eye on the 10-line layout. Premiums hit from two of a kind, royals from three, all starting on reel 1. The book symbol pulls double duty as wild and scatter. You trigger 10 free spins from three books, and you can also retrigger in the feature. If base play runs cold, the Wild Collection meter is your alternative route, awarding the same bonus when it reaches 99.

I sometimes raise my stake when the meter edges close to full or when the feature feels due, but I stay mindful of the high variance. The chosen expanding symbol makes or breaks the round, and premiums need fewer to expand, so they can swing results hard. Pace your spins, set a stop-loss, and let the maths breathe. The 99% RTP is about the long run, while the short run lives and dies by those expanding screens.