Game description

Book of Oil Slot (Endorphina)

Book of Oil Slot (Endorphina)In contrast to previous book titles, this one is a Book of Oil slot that Endrophina designed, and you can probably guess what inspired the developer based on the title.

The Book-style is a very popular design, and I will share my review in the article below:

Game Set-Up

The very basic features include a 5x3 grid that holds 10 ways to win. In addition, other features include Free Games, Wilds, and Scatters among others.

Betting and Prizes

Now that you have a basic understanding of the game, the next thing that we will look into is the prizes.

I can proudly say that I was happy to place bets of between $0.10 and $100 per spin. This is a very good betting range since it ensures that players of all levels have a chance.

Top prizes on this title are not as bad, and it’s possible to hit wins of about 5000xs the stake.

Book of Oil Features

The Book of Oil symbol is a special icon that serves as both a Scatter and a Wild. All regular symbols in the game can be replaced by the Wild, and this increases your chances of winning.  However, it is good you note that expanding icons cannot be replaced while in the Free Games mode.

Three or more of these symbols anywhere on the reels helped me to activate the bonus rounds of up to 10 free games.

An additional bonus feature appears in the form of an expanding symbol, which can appear anywhere on the reels. This is one of my favourite symbols because, with its help, I was able to form winning combos. In addition, I also received a Gamble feature.

Another interesting concept is the use of face-down cards. I was supposed to pick one, and the Dealer one. If mine has a higher value, I received a 2x multiplier. This can be done multiple times.

Last but not least of the features is the Bonus Pop Buy Feature. It is the feature that will allow you to buy the bonus spins that have an expanding symbol.

Theme and Design

As previously stated, the storyline of this game is inspired by the oil industry. In the background, I noticed several dazzling buildings, oil drilling machines, and barrels of oil. This game looks great on mobile devices and works just as well.

The assortment of symbols includes a common set known as the royal card symbols, and they serve as low pay icons. 

Others are a pile of cash, some oil barrels, oil drilling equipment and an oil executive as premium symbols.


Book of Oil is a fair slot game, and Endorphina has done a good job with this fairly new theme.

I love the mix of popular and new types of symbols that work well at delivering the oil trade experience to gamers.

This slot has all a gamer would be looking for: from a fair RTP to good payout potential, it’s a slot that I can recommend to all levels of gamers.

UPDATED ON: by Shawna Dudley