Book of Yog Idle RPG

Released Jul 2022

The Book of Yog is a 3D idle RPG game presented with a Cel-Shading art style. You can rally heroes, develop the kingdom and explore the secrets of a lost world. Dozens of heroes, hundreds of skills, thousands of loot for you to combine freely. Come to embark on a journey to build the strongest team!

65% positive · 9,043 reviews

Not yet

Released, ongoing live service game

High confidence

Live Service

Not yet

Released, ongoing live service game

High confidence

Live Service

Where to get it

Free on Steam

Steam Free

Evaluation

Book of Yog is a free-to-play live-service idle RPG that officially launched out of Early Access on April 28, 2025. The game operates on a continuous content cycle with biweekly-to-monthly major patch updates, rotating character banners, seasonal PvE modes, and recurring limited-time events. The August 13, 2026 patch (the most recent, just two weeks before today's date) introduced new character reruns, multiple time-limited events, balance adjustments, and previewed upcoming content including a new Boss battle for Paradox Sailing Chapter 2 and a new region called Lionmouth Town in Starborne Era — confirming active development is continuing beyond the current patch. Developer communications throughout 2025 reinforce a long development runway: a July 2025 anniversary post outlined sweeping plans for new systems including pets, fishing, open-world PvP, and a seasonal balance mode; an October 2025 post confirmed that the Otherrealm system launched at roughly 25% of its total planned scope with more content rolling out each season; a November 2025 post previewed new Otherrealm stages, expanded skin content, Steam Marketplace integration, and combat overhauls. All five DLC packs on record are seasonal content bundles consistent with this live-service structure. The game continues to receive new characters, systems, gameplay modes, and events on a regular cadence with no indication from the developer that content development is winding down.

Evidence

August 13 patch delivered new character reruns, multiple limited-time events, balance fixes, and previewed upcoming content: a new Boss battle in Paradox Sailing Chapter 2 and a new region (Lionmouth Town) in Starborne Era.

news post · Aug 13, 2026 source content planned

high

July 28 patch introduced a new SP character (Moondepth Dragonmaiden), new class change paths, a new story event, new PvE mode (Shadow Spirit Trial Tower), new Void Chasm content, and companion system expansions — a substantial content drop.

news post · Jul 28, 2026 source content shipped

high

Content

5 of 5 released · no outstanding content

Released

依盖之书-冰柠夏季拓展包

May 2025

Released

依盖之书-悠闲时光拓展包

Jan 2025

Media

Details

Developer

元气工作室

Publisher

元气工作室

Achievements

—

Platform

Windows

Controller

—

Steam Deck

Playable

Players

Single-player · Multiplayer

Hack and Slash Loot Horror Nudity Action Free to Play Visual Novel Indie Incremental Psychological Horror Adventure Casual Female Protagonist Idler Anime

About this game

*** For information about current state of the Early Access version, please refer to "From Game Developers" section in this page. ***

Recruit heroes, build a team, and explore an idle ARPG with an in-depth strategic system!

Step up to be the Commander of “Arkrance” Strike Force, recruit the unique heroes of “Black Guard” and form your own team, slay and push back the vicious monsters emanating from the "Black Tide", defend the teetering Arkrance Great Wall, and find out the truth behind these apocalyptic turn of events.

Experience an interesting and relaxing idle RPG. There are heroes, skill tomes and loot that are waiting for you to mix and match into the strongest team with the most powerful heroes in order to overcome any obstacles that are thrown in your way.

Main feature

Idle system

Experience an easier idle ARPG! You can progress even when you are offline. No need to waste time in meaningless battles. Facilitate the growth of your team, to enjoy the game at your own pace!

Heroes

Dozens of heroes are waiting for you to recruit (30 in early access), and more heroes are waiting to join the game. There are 6 unique classes waiting for you to choose: Warriors, Tanks, Rangers, Assassins, Mages and the Support class. Each class has its own unique and special class system and talent trees. If you like RPGs, this will be right up your alley!

Strategy System

Experience the rich in-game strategic system to maximize your potential, customize the items, skills, talents, characters freely to make your own perfect hero!

Skill Combination

Each hero has their own unique skill trees and talents, collect special skill tomes to customize your heroes' skill trees. Feel freely to collect, learn and combine. And create a most fun and powerful hero to improve the combat strategy and the fun of the game!

Team Formation

Assemble a team with 4 "Black Guards" to fight with you. Different team combinations can activate different unique and powerful synergistic effects. There will be paths to victory even if you decide to have a team of 4 tanks or 4 supports. The choice is up to you!

RNG System

Explore the wilderness, battlefields, and dungeons, and slay the monsters to get thousands of unique loot, all of which are randomly generated. Each battle can bring an unexpected reward and experience!

Loot System

It’s an idle game for a reason, play at your own pace. There’s no need to invest too much effort, nor is there need to P2W. Whether it is loot, skill tomes, skill materials or even heroes, they can be gained easily through normal gameplay.

Sand-box System

You can DIY your own lodgings with the sand-box construction system, enjoy a fun, relaxing and personal game experience! (Under development, not released yet)

And more game contents will be published with our continuously update, please stay tuned!