
Book of Oil Review
Game Specifications
Mechanics: 5-reels • 3-lines • 10-Game
Features: expanding symbols
Return to Player (RTP): 96.5% *can vary between casino sites
Volatility: High – Medium
Developer: Endorphina
Rating: 7.5/10 Stars.
Comment: Brilliant new theme in a game that hasn’t got what it takes. Interesting game though, with a brilliant gamble feature
*All games have been played and tested by us in a neutral environment that is not dependent on or influenced by any Casino or game provider.
Game Content
The Book of Oil is a strange game. Not strange to play, just the concept and idea are a little strange, sort of an 80s’ nod to JR Ewing and the Dallas team. That said, it’s a good game to play. The graphics aren’t great, and the soundtrack is a little dull, but there is more to this game that meets the eye.
It looks like an old-fashioned Book of… classic that won’t sit on the top of too many lists, nor will it be on the bottom. As with all Book games, this game is easy to play, and for the most part enjoyable up to a point. That said, it comes with a warning, game play is fast, especially in auto-mode.
Safer Gambling Features
This game comes with a 5 star rated Safer Gambling features. All of which, are run through the autoplay mode. These stop-safe features are numerous and customisable. You can limit the number of Spins, Play time, Stop when Single Win, Stop when balance decreased by, and Stop when balance increased. All of which need to be manually adjusted but are worth the effort and act as a handy way to control your gambling.
The Book of Oil comes with a fabulous statistics chart too This lets you know exactly how much you’ve played, won, and most importantly lost. This is the most important tool in the game, so make sure you use it. Having live play info is crucial when it comes to a safer gambling environment for players.
Bonus Features
Free Spins
The Book of Oil is built around the classic scatter symbols that you’d normally get with any Book of… slot. Three Book of… symbols trigger the Bonus spins and you are then taken to the actual Book which reveals your Bonus symbol, and the spins begin. You start with 10 free spins.
Prizes in this game are not massive, but you get to win a surprising amount of times. I dropped a few big pots in this game too. Including, the Free Spins that just kept adding free spins. No complaints here!
Gamble Feature
This is possibly the best gamble feature in a Book of… game yet. As far as gamble features go, it looks basic enough, but is done in a clever way that allows the player to “backout” of the bet. It’s a simple higher-lower card game where the first card is shown, then you need to pick a face-down card and hope that its higher. There are 4 to choose from, so the odds are not completely against you. However, it’s a gamble feature so nothing is guaranteed.
The first card is shown face-up, which makes things a little easier, as you still have the chance to walk-a-way (collect) rather than gamble. Basically, if the card shown is a king, then your chances of getting higher are seriously slim, so you collect. If the face card is a 2, it’s a no-brainer, gamble. Cards of equal value cancel out the win/loss, so you are dealt new cards.
Bonus Pop feature
This game comes with a “Bonus pop” feature which is a Buy feature. You need to opt-in for this feature and it will cost you 6900x your bet to guarantee 3 Book scatter symbols, which lead to 10 Free Spins. “Free” being a poor choice of words, as this is an expensive feature that you don’t need. Once chosen, your funds are debited the amount and you are taken to the Bonus round.
In order to make this feature pay for itself, you need to win more than your starting fee. The cheapest buy-in is €6.90, but with a starting bet of €0.10 and an average win of between €0.20 – €0.60, you’ll need a small miracle to break even. It’s possible, but I’ve tested similar features on hundreds of games and probably evened out 10 times. My advice is to play the game the way it’s meant to be played, one spin at a time.
Book of Oil Game Conclusion
What appears to be a basic Book of… game is in fact, a basic Book of.. game, but there is depth to the Book of Oil that you have to dig deep to find (excusing the pun). The features that come with this game make it a playable game, which is annoying, as I really wanted to dislike this game. That said, it isn’t going to make any top 10 lists anytime soon, and with the exception of the fabulous Gamble Feature and the Bonus Pop feature, there isn’t much to this game.
Endorphina are masters at making game themes stand out, and they have done too, just not in a way that warrants the Endorphina badge. This game producer is one of my favourites, with games that stand out. The Book of Conquistador, or the Book of Vlad comes to mind, but the Book of Oil isn’t in that league.
Game Developer

Endorphina games range from innovative and traditional themes to provoking and cute ones, such as Taboo Slot which embodies the “adult-themed” games. There are plenty of modern and trendy games that manage to capture that old-school feel too.
There are lots to like about the direction that Endorphina is taking, all they need now is a more impressive list of Books of… games to top it all off. Other brilliant Book of… games by Endorphina include the fabulous Book of Vlad, Book of Conquistador and the Book of Lady.
Age Verification
All slot/casino games are gambling-related and for adults only. Proof of ID is always needed when registering with any online Casino where this game is available. 18+ BeGambleAware.org
Responsible Play – Adults-Only Game
18+. When selecting an online Casino, all welcome bonuses refer to new players or first-time depositors only. Wagering requirements always apply unless specified. Bonuses, RTP %, Providers, Casinos, Games and Wagering requirements may change depending on where you play. Free games and promotions are for funded players unless specified. Withdrawing funds requires proof of an ID. Always read full T&C’s before playing.
Below is a selection of casinos that host games from this game provider. For more information on any of the below
online Casinos, click on the image to go to our Casino reviews.
The BigBookofSlots is an affiliate site, which means that we earn our crust by referral. For more information read our About Us page.