Book of Shadows slot review

Book of Shadows slot at a glance

Book of Shadows comes from Nolimit City, the Malta-registered studio co-founded by Jonas Tegman and later bought by Evolution in a deal announced in June 2022. The game itself launched on 20 August 2020, so it predates that takeover. The headline numbers below are the developer's published figures as recorded in our checked data.

Two words in that table deserve attention before anything else: default and extreme. Default means 96.01% is the standard configuration; a casino can run another approved version, so the figure in the game's help screen is the one that counts. Extreme is Nolimit City's highest volatility band, and it shapes almost every session you will have on this game.

How the features work in Book of Shadows

Book of Shadows takes the familiar book formula and adds one decision that is yours to make: how big the grid is. That choice feeds through to the base game and to the bonus, so it is worth understanding before the first spin.

Picking three, four or five rows

Before spinning you choose to play with three, four or five rows. The row count sets the paylines: 10 with three rows, 15 with four and 20 with five. It also shapes the free spins, because a smaller grid earns more spins when the bonus starts. The setting is a trade-off rather than an upgrade: more lines on every spin against a longer bonus round.

The Book and the free spins

The Book is the wild and the scatter at once. It completes line wins by standing in for other symbols, and three or more Books anywhere on screen start the free spins.

At the start of the round, one symbol is drawn at random to be the golden symbol. Whenever it forms a win during free spins, it expands to fill each reel it sits on, so a short line can become a screen of matching symbols. On the five-row grid, golden symbols on all five reels would cover all 25 positions.

Three or more Books during the round retrigger it. The help screen sets out how many spins each grid size receives and what the golden symbol pays, and OLBG's Book of Shadows review (opens in a new tab) gives an outside summary of the same rules.

How the Book of Shadows slot grows its paylines

Most book-titled slots use a fixed 5x3 window with 10 lines. Book of Shadows starts there too, but you can choose to play it with four rows or five. Each step adds lines: 10 paylines on 5x3, 15 on 5x4 and 20 on 5x5. More rows mean more symbol positions (15, then 20, then 25) and more lines on which a combination can land, which is where the bigger results tend to come from.

The row count is your own choice before you spin, and the section above explains how the book symbol and the free spins round work with it. Nolimit City is known across its catalogue for 'x' mechanics such as xWays, xNudge, xSplit and xBomb (see our xWays and xNudge guide), but which of these, if any, appear here is a question for the in-game rules rather than an assumption.

The last column is simple division, but it shows the design idea: the bigger grid is not only larger, it is more densely covered by lines, so each extra row adds proportionally more ways for symbols to connect.

Book of Shadows RTP: the cost in pounds

An RTP of 96.01% leaves a house edge of 3.99%. Expected loss is stake multiplied by house edge, so every £1 you put through the reels costs about 3.99p on average over the very long run. Across a single session the result can be wildly different in either direction; the average only describes where millions of spins settle.

The 600-spin column is an illustration, not a target. UK rules require at least 2.5 seconds per spin, which caps play at 1,440 spins an hour, but 600 spins is a more typical steady pace. At 50p that works out at roughly £12 an hour on average, which is a fair way to think about the price of the entertainment.

Extreme volatility and a £20 budget

Volatility describes how unevenly the RTP is paid out. On an extreme game, a large slice of the 96.01% sits in rare, big results (the Wizard of Odds slot guide (opens in a new tab) makes the same point about RTP and volatility varying independently), so the ordinary spins return much less than 96p in the pound. The practical effect is that a £20 budget behaves differently at each stake level.

• 10p a spin: £20 covers 200 spins before any returns. If you staked the £20 once through, the average cost would be about 80p, but on an extreme game the spread around that is wide and running out is common.
• 50p a spin: 40 spins before returns. That is a short window for a game whose biggest outcomes are rare, so many sessions at this level end before the grid has done anything notable.
• £1 a spin: 20 spins. This is a very thin budget for extreme volatility. You are effectively buying a handful of chances at a large result rather than a session.

The Book of Shadows max win in context

The top prize is 30,338 times the stake. That is the ceiling for a single game round, not a likely result, and our max win explainer covers why caps like this exist. Here is what the figure means at common UK stakes, including the two legal maximums for online slots.

Nobody publishes how often the cap is reached, and we do not repeat third-party estimates of it. Treat the figure as the edge of the game's range. It helps explain why the volatility is rated extreme: a ceiling this high has to be paid for by many quieter rounds.

Book of Shadows compared with other book slots

The book slots family is mostly fixed 5x3, 10-line games. Book of Shadows stands apart through its expanding grid and a much higher ceiling, at the price of slightly lower RTP than some rivals.

On cost alone, Legacy of Dead is the cheapest of these at 3.42% house edge against 3.99% here: on £500 staked that is about £2.85 less in average losses. If you like Nolimit City's extreme maths in a more elaborate package, Mental goes further still. Browse the full range in our slot reviews.

Playing Book of Shadows online in the UK: the rules

Several Gambling Commission rules change how this game runs for British players compared with versions you may see described elsewhere.

• Stake limits: £5 per spin if you are 25 or over (from 9 April 2025) and £2 if you are 18–24 (from 21 May 2025). See our slot stake limits page and the Commission's online slots stake limit guidance (opens in a new tab).
• Spin speed: at least 2.5 seconds per spin, with no turbo or slam-stop, under the game design rules.
• No autoplay: every spin must be started by hand (autoplay ban).
• Feature buys: since a Gambling Commission warning in January 2020, feature buy-ins are not offered to British players, so any bonus-buy option seen in other markets will not appear. Our feature buy rules page explains why.
• Real-time display: your net spend and time played must be shown as you play, and wins smaller than your stake can't be celebrated as wins.

The full design standard is in RTS 14 on responsible product design (opens in a new tab).

How to play Book of Shadows step by step

1. Open the game at a UKGC-licensed casino after your age and identity are verified, which is required even for demo play.
2. Open the help screen, confirm the RTP version and check how many free spins each row setting gives.
3. Set a deposit limit and decide your session budget before the first spin.
4. Choose a stake that gives you enough spins for an extreme-volatility game: 10p gives 200 spins from £20.
5. Press spin for each round; there is no autoplay, and each spin takes at least 2.5 seconds.
6. Watch the net position display, and stop when your budget or time limit is reached, win or lose.

Book of Shadows myths and facts

Where to play Book of Shadows and the related offers

None of our partners lists Book of Shadows in our checked data, so check each casino's game lobby before joining. The offers below are slot offers that apply to selected games, not to this title specifically. All are for 18+ new customers and terms apply.

• PlayOJO: first deposit of £10 or more gets 80 free spins on Big Bass Bonanza at 10p each, with no wagering and winnings paid in cash. UK only, excluding Northern Ireland; via the designated offer link and not with other offers.
• Coral: deposit and bet £10+ on slots to get 100 free spins on selected games at 10p each, accept within 48 hours, valid for 7 days, no wagering. Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards don't qualify.
• Ladbrokes: deposit and spend £10+ on slots for 50 free spins a day for 10 days (up to 500) at 10p on selected games, claimed before 23:59 each day, valid for 7 days, no wagering. Prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits don't qualify.

Coral and Ladbrokes are both run by LC International Limited, so you may not be able to open new accounts at both. Read our PlayOJO review and the no wagering bonus guide before you choose.

18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.