Every article on Book Slots carries one signature, and it is mine. I opened five of the nine titles in the studio's own demo client, six clients in all, because Playson serves Book of Gold twice, and read the rules screens each one gave me. I shot 16 of the 29 frames published here; the other 13 come from the Book of Dead demo run of — six of them from the two recorded sessions, the rest from the intro book, the base game at rest, the three paytable pages, the bet panel and the rules window. Twice a studio would not let me in at all, and I wrote that down too. I have never played any of these titles for real money, and nothing here is written as though I had.
By Daniel Hart, slot maths analyst · Published · Updated
Role
Slot Maths Analyst, writing and editing this catalogue
The work started in the clients the studios serve themselves. I opened Book of Gold: Classic and Book of Gold: Multichance through Playson's own demo button. Book of the Fallen and Book of Tut Megaways went through Pragmatic Play's launcher, and Book of 99 through Relax Gaming's Try Game link. Book of Dead I had read a week earlier, on , in the same way. Its frames are reused here rather than shot again, and the pages that use them say so.
In most of those clients I read the rules screens in order and noted the bet it opened on, the play-money balance it granted and every screen that carries a figure. On Book of Tut Megaways I never got past the opening screen, and the page covering it says so. On Book of 99 that is five screens of about nine, which is why this site does not say Relax prints no return anywhere — only that it prints none on the screens we read. That reading is where the odd findings come from. Pragmatic prints WIN UP TO 5,000 X BET on the splash of Book of the Fallen. On Book of Tut Megaways it prints nothing of the sort. Playson's two clients name no return and no ceiling anywhere, and neither does its game page.
Then the arithmetic, which is the part I am paid for. Book of the Fallen sells two different things on one screen. A Super Spin ante at 10x the total bet for every spin, and Buy Free Spins at 100x once. Calling both of them bonus buy would be wrong by a factor of ten on the first spin, and by more with every spin after it, so this site does not. Wins under the ante are also counted from the base stake, not the raised one, which is easy to read past.
Two Studios Said No
Greentube serves no public demo for the Book of Ra family. Its own launcher answers an anonymous request with 401 Unauthorized, because sessions go to licensed operators. The aggregator copy I tried loaded to a black screen. Nolimit City serves Book of Shadows only behind a playin.com account, and I did not open one.
So four of the nine titles here have no session behind them at all. I would rather print that sentence than fill the gap with someone else's screenshot, and the pages concerned carry the same admission at the top.
Reading the Casinos When the Studio Is Silent
Greentube publishes no return, no ceiling and no rules document, which leaves the operators that are obliged to publish. I read Admiral Casino UK's live page for Book of Ra Deluxe on , where it prints 92.13%. I also read an archived Grosvenor Casinos page from , where the same game is 94.26%. Admiral is a Novomatic brand, the studio's own group. So the lower of the two figures is published by an operator inside the studio's own group, while Greentube still publishes no figure of its own.
Where a figure came from an archive instead of a live page I say so and date it. A geo-blocked page read through a snapshot is weaker evidence, and hiding that would make the stronger figures look worse than they are.
How I Score, and Why the Numbers Are Boring
A game score here is the plain average of five named criteria: return transparency, ceiling clarity, feature depth, bet range and documentation. No weighting, no rounding in my favour, one decimal. It measures what a reader can check before depositing and nothing else. That is why Book of 99 scores well on transparency, with a 99% return published by its studio, while the Book of Ra family scores badly because its studio publishes no return, ceiling or rules document and the only figures belong to casinos.
It is a deliberately narrow instrument. It says nothing about whether a game is fun, and I would not trust it to. Two titles can sit a point apart and play nothing alike.
What This Desk Does Not Do
Not done
Why
What stands in its place
Real-money play
A funded session measures nothing a published return does not already say
Returns quoted from studios and licensed operators, with the publisher named
Casino accounts
An account would put me behind a login a reader does not have
Operator pages read as a visitor reads them, with geo-blocks reported
Spin-level proof
These are RNG reel games: no seed, no hash, nothing a player can re-check
Paytables, rules text, bet ranges and licence numbers, all of which can be checked
Filling a gap by analogy
Two games by one studio already disagree about what the client prints
The gap is printed as a gap on the page where it falls
Corrections Reach Me Directly
If a figure on any page here is wrong, send the document and the date you read it. Email is the only address the desk publishes. Write to [email protected]. No individual reply is promised: a correction that holds up shows as a changed page with its update date moved, and that change is the answer. Where two sources disagree, both get printed with the name of whoever published each. That is how the 92.13% and the 94.26% ended up side by side rather than averaged into a number nobody published.
Frames from the Sessions Behind This Byline
These are Book of Dead screens: the paytable I read in the client, and two shots from the recorded demo sessions of , which were the only play behind any page here and were in play money. The rest of the frames on this site are rules and paytable screens from the other clients that opened.
The third paytable page, per-line and without a percentage: A and K at 150, 40 and 5, the cheapest cards at 100, 25 and 5. Source: our own screenshot.The second session's feature closed at 3,250 coins, 65 times the bet that triggered it. The first paid 675. Source: our own screenshot.The same win in two units: 3,250 coins in the message bar, 65.00 in the status bar beside a balance of 25,028.50. Source: our own screenshot.
Deposits and identity checks stay on the operator's own secure site.
Related Reading
Elsewhere in this catalogue, from the same section first:
