Book of Shadows review
Book of Shadows is a Nolimit City slot from 20 August 2020 in which a book of spells supposedly rewrites the reels themselves. Instead of one rigid grid it offers a construction kit: you decide how many rows and lines to have, which reels to freeze after a spin and whether to gamble a win for a double.
A book in a dark forest: what the blurb promises
The studio’s description fits into one line: a book of enchantments hides in the shadows and gives the power to change the setup of every spin. The word “interactive” is not decoration. Normally you press a button and watch, but here there are choices between spins, and before the bonus you can redraw the key symbol.
The look is gloomy: a red hand-lettered logo on a pale background and an eerie face in the haze. Of the details that matter for play, only one needs remembering: the expanding Golden symbol in the bonus. Everything else rests on the decisions you make.
What the studio sheet shows
The sheet’s numbers come from a ten-billion-spin simulation. The studio labels the volatility Extreme (10), and the split of the return explains why: of the 96.01%, the main game holds 58.70% and the bonus 37.31%. The bonus lands once in 154 spins on average, so it is worth about 57.5 bets (37.31 × 154 ÷ 100).
The sheet puts a win of 100 bets at one in 843 spins, which is one for every 5.5 bonuses (843 ÷ 154). So no more than a fifth of bonuses, about 18%, get to 100x, and a typical bonus finishes well under its average price. Frequent hits, roughly every third spin, do not change the picture: a considerable share of payouts is smaller than the stake, and without bonuses the game rests on the base share of the return alone.
Besides the main version there are DX1 at 94.09% and DX3 at 90.15%. The spread is wider than in most of the studio’s slots: DX3 gives back almost six points less than the main version. The ID in the game’s help gives the version away: BookOfShadows, BookOfShadowsDX1 or BookOfShadowsDX3. The developer’s trial version runs without sign-up.
Shadow Rows: paying for extra rows
Shadow Rows lets you increase the number of rows, and with it the number of paylines, for an extra fee. In return the studio promises more frequent wins and bigger payouts. The grid grows from the basic 5×3 to 5×4 and 5×5, and the expansion applies to ordinary spins as well as to the free ones.
The sheet gives neither the price of the extra rows nor the number of lines for each grid size, but the logic is plain: more rows, more lines, more frequent combinations and a dearer spin. You are paying for better odds while the symbol pays stay the same, and the studio makes no claim that the RTP rises with the row count. “More expensive” does not mean “better value”, and the price of a row is in the game’s help.
Boosted Bet: why the cap is €200
The normal stake runs from €0.10 to €100, with €200 listed for Boosted Bet. That suggests a raised-stake mode in which the normal bet is multiplied by an extra factor. What exactly it does, the sheet does not explain, and no properties should be attributed to it. The only thing known for certain is that in this mode the charge per spin can exceed €100. If your operator has the mode switched on, the help describes it, and its price should be counted as part of the bet.
Lucky Locks: freezing reels after a spin
After each base-game spin you are offered a choice of reels to keep in place and reels to spin again. The respin costs an adjusted bet, and the studio gives no formula: the game shows the price each time.
In Book of Shadows a scatter doubles as a Wild, and three or more of them start the free spins. Hence the main scenario: two scatters sit on the grid and you need a third. You freeze the reels holding the scatters and respin the rest; holding scatters, the studio says, raises the chance of the free spins. A frozen scatter also stays in the combination as a Wild, so a respin sometimes does two jobs at once. It is the one way to pay directly for a target instead of waiting for the bonus to come on its own.
Whether a respin pays for itself can be judged without the studio’s formula. With a bonus worth about 57.5 bets on average, a respin costing c bets is justified only if it raises the bonus chance by at least c ÷ 57.5: 3.5 percentage points for a two-bet respin, 17.4 for a ten-bet one. Two scatters held with three reels to respin usually give a far higher chance, while one scatter and five loose reels probably do not.
Free spins with the Golden symbol
Three or more scatters award 10 free spins. The main difference in the bonus is the Golden expand symbol. When it lands and produces additional wins, it expands over the whole reel. The studio stresses that with full screens of symbols the payouts can become big.
The expansion does not always happen, only when it brings a win. That guards against pointless expansions but also makes the bonus depend on which symbols already sit on the board. The more matching symbols on neighbouring reels, the higher the chance that the Golden symbol turns into a real win.
Choices inside the bonus: the redraw and the rows
If you do not like the first draw of the Golden symbol, you can make a redraw. How many times, at what price and with what limits goes unsaid. Only one thing is certain: the right to a redraw exists, and it turns the bonus from purely random into partly controlled. You see the draw, so you have information: keep a high-paying symbol and consider trying again on a low one.
The free spins themselves can be chosen with more or fewer Shadow Rows, and the number of spins granted changes accordingly. The studio gives no conversion table, and it does not say which way the relation runs, so check in the game. It is reasonable to assume the choice comes down to tempo: more spins on a narrow grid or fewer on a wide one.
The 50/50 gamble: double or nothing
A win can be put on the gamble, effectively a coin toss: a 50% chance to double and a 50% chance to lose it all. There is also Gamble to bonus, which plays the win straight into free spins. The studio warns that in some regulated markets both features are switched off.
With a fair 50/50 the expected value of the gamble is zero: on average it adds nothing and does not “give back” what you lost, it only widens the spread. Four successful tosses in a row turn a win into x16, but only 6.25% of attempts get there. The studio gives no exact chance for Gamble to bonus.
Buying the bonus: what is missing for a decision
The studio says you can buy entry straight into the free spins, but neither the price nor the RTP of the bonus buy is on the sheet, so the value cannot be calculated. There is one yardstick: an average bonus is worth about 57.5 bets. If the buy price is well above that, you are paying for certainty, not value; if it is below, check exactly which bonus you are being sold and with how many rows.
Book of Shadows among the book slots
Book of Dead — Studio: Play’n GO; Release: 14 Jan 2016; RTP: 96.21%; Max win: 5,000x.
Legacy of Dead — Studio: Play’n GO; Release: 2 Jan 2020; RTP: 96.58%; Max win: 5,000x.
Book of Shadows — Studio: Nolimit City; Release: 20 Aug 2020; RTP: 96.01%; Max win: 30,338x.
By name they are neighbours, but the maximum differs sixfold. How often Book of Shadows reaches its limit the sheet does not say, but the limit itself, thirty thousand bets, stands well above the book slots of other studios. Its RTP is slightly lower, and it offers what classic “book” slots lack: the right to choose the grid and replay your spins. The best-known slot with an expanding symbol is Book of Dead, and a newer sibling in the genre is Legacy of Dead. More games of the kind are gathered in the roundup of book slots, and the developer’s whole catalogue is on the Nolimit City page.
