Endorphina

Book of Oil

Oil-industry book slot with a compact fixed-line format

SlotRanker Score

/ 99

05099

The SlotRanker Score is calculated from the visible data below. It is not affected by affiliate deals, and it cannot be bought.

How this score is built

RTP

96.05%

return to player

Volatility

Medium volatility

variance

Max win

—

top multiplier

Min bet

$0.01

per spin

Reels

10 lines

Player rating

4.5 ★

3 votes

DEMO Play free, no signup

Endorphina

Embed on your site

4.5 / 5

3 ratings

User ratings are shown separately from the Slot Score unless stated otherwise.

Five weighted signals shape the composite. Four context signals refine ties. See how we rate for the full methodology.

Payouts & RTP9/10

RTP 96.05% → 9.0/10

Volatility8/10

medium → 8.0/10

Win Potential—

no data

Features7/10

11 features → 7.0/10

Game Mechanics4.2/10

f=11 r=5 p=10 → 4.2/10

Context signals (tie-breakers)

Layout6/10

5x3 → 6.0/10

Bet Flexibility8/10

0.01–50 (×5000) → 8.0/10

Provider Reputation6.6/10

provider avg 6.6 → 6.6/10

Popularity6.7/10

synthetic proxy → 6.7/10

Popularity blends real player search demand (~30 markets) with a catalogue-derived proxy; games without measurable search demand use the proxy alone. Not live play telemetry.

Cite this score

SlotRanker Score: 73 — Book of Oil by Endorphina

https://slotranker.com/endorphina/book-of-oil#score

How to cite

Slot Summary

A five-reel grid with ten paylines gives Book of Oil a compact format, while its 96.05% RTP supplies the clearest numerical reference point. Endorphina uses the book symbol as both Wild and Scatter, then changes the pattern during Free Spins by selecting a special symbol that can expand across enabled lines. The oil-tycoon setting connects the Business and Industry themes directly to that familiar book-slot structure.

How It Plays

Wins are evaluated across ten fixed paylines on a five-reel, three-row layout. The book substitutes as a Wild during ordinary play while also serving as the Scatter trigger.

The Risk Game provides a separate decision after eligible wins. That option changes the immediate choice from collecting the result to risking it under the game's gamble rules.

Theme & Atmosphere

Book of Oil treats the Business and Industry themes as an oil-boom fantasy, using tycoons, derricks, tanks, and petroleum wealth as its central subjects.

The setting frames oil as a luxury commodity rather than an engineering simulation. Its emphasis falls on ownership, machinery, and concentrated industrial wealth.

Business Industry

Features & Win Potential

The book symbol handles two jobs in the base game. It substitutes for regular paying symbols as a Wild and counts independently as the Scatter.

The Gamble option sits outside the normal reel evaluation, allowing an eligible win to enter a separate risk decision instead of being collected immediately.

Free Spins Scatter Symbol Wild Symbol Medium volatility 5 Reels Gamble Bonus Buy Additional Free Spins 10 Paylines 96% RTP Risk/Gamble (Double) game

Bonus & Free Spins

Three Scatter symbols award ten Free Spins. Before the round begins, one special symbol is selected, and that symbol can expand after ordinary payouts are evaluated.

Additional Free Spins can be awarded during the round. The Wild does not replace the selected special symbol, preserving a separate role for each symbol type.

Spec sheet

Book of Oil at a glance.

Identity

Slot nameBook of Oil

StudioEndorphina

Released9/17/2021

Math

SlotRanker Score73

RTP96.05%

VolatilityMedium volatility

Max win—

Bet range$0.01 – $50.00

Player rating4.5 / 5 · 3 votes

Format

Reels5

Paylines10

Layout5x3

Features

Themes

Expected average based on this slot's 96.05% RTP — individual sessions vary with volatility.

Bet per spin

Spins per hour400

Session length (hours)

Cost per hour$0.16

Cost per session$0.16

Estimate only, for entertainment purposes — treat gambling as entertainment, not a way to make money, and set a budget you can afford to lose.

How long could a bankroll last on Book of Oil? We simulate thousands of sessions from this game's published RTP and volatility — the long-run math, not a prediction of your next spin.

Bankroll ($)Bet per spin ($)Speed

Volatility tier: Medium

Running simulation…

How this works

Each simulated spin either misses or returns a win drawn from a log-normal distribution, with the hit rate and spread set by the slot's volatility tier (Medium). The model is calibrated so the average return equals this slot's published RTP (96.05%), with wins capped at its top multiplier (1,000×).

This is a simplified, parametric model of the game's math — not its real paytable. It exists to make the house edge visible over many sessions, so the numbers above are averages across thousands of runs, never a forecast of one.

This is math, not a prediction. Real sessions vary wildly, and no strategy changes a game's built-in house edge. Play for fun, set limits, and never bet more than you can afford to lose.

Where to play Book of Oil

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Compare Book of Oil with other games

	Book of Oil Score 73This game	Outsourced Score 83	Texan Tycoon Score 65	Labour Day Score 63	Slot Factory Score 61
Identity
Studio	Endorphina	NoLimit City	Realtime Gaming	Onlyplay	Slot Factory
Released	9/17/2021	8/6/2024	4/26/2010	4/30/2024	7/13/2023
Math
RTP	96.05%	96.08%	—	95%	96%
Volatility	Medium volatility	High volatility	High volatility	Medium volatility	Low/Medium
Max win	—	5,000×	—	4,103×	—
Format
Reels	5	5	5	5	5
Layout	5x3	5x3	5x3	5x3	5x3
Paylines	10	256	25	5	15
Min bet	0.01	0.2	0.25	0.1	0.15
Max bet	50	280	125	50	45
Features
Progressive	—	—	✓	—	—
Wild symbol	✓	✓	✓	✓	✓
Free spins	✓	✓	✓	—	✓
Scatter symbol	✓	✓	✓	—	—
Multiplier	—	✓	✓	✓	—
Bonus game	—	—	—	✓	✓
Respins	—	—	—	✓	—

Every number is shown as a delta against Book of Oil.

Comparing against

Book of Oil

Endorphina

RTP

96.05%

Max win

—

Score

+ Progressive+ Multiplier

+ Multiplier+ Bonus Game+ Respins− Free Spins− Scatter

+ Bonus Game− Scatter

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