Games like Eschalon: Book I
Games like Eschalon: Book I include UnderRail, Avernum: Escape From the Pit, Divinity: Original Sin (Classic), Pillars of Eternity II: Deadfire, and Pillars of Eternity. We matched them by the tags players give Eschalon: Book I on Steam (RPG, Indie, Isometric, Turn-Based, and Fantasy): closest matches first, and among equally close ones the better-known games.

UnderRail
Shared: RPG · Isometric · Turn-Based

Avernum: Escape From the Pit
Shared: RPG · Indie · Isometric

Divinity: Original Sin (Classic)
Shared: RPG · Turn-Based · Fantasy

Pillars of Eternity II: Deadfire
Shared: RPG · Isometric · CRPG

Pillars of Eternity
Shared: RPG · Isometric · Fantasy

Fallout: A Post Nuclear Role Playing Game
Shared: RPG · Isometric · Turn-Based

Ruined King: A League of Legends Story™
Shared: RPG · Isometric · Indie

Shadowrun Returns
Shared: RPG · Isometric · Turn-Based

Pathfinder: Kingmaker - Enhanced Plus Edition
Shared: RPG · Isometric · Fantasy

Fallout 2: A Post Nuclear Role Playing Game
Shared: RPG · Isometric · Turn-Based

Chained Echoes
Shared: RPG · Turn-Based · Indie

Swords and Souls: Neverseen
Shared: RPG · Indie · Turn-Based

Battle Chasers: Nightwar
Shared: RPG · Indie · Singleplayer

Lords of Xulima
Shared: RPG · Indie · Turn-Based

Divinity: Original Sin - Enhanced Edition
Shared: RPG · Turn-Based · Fantasy

觅长生
Shared: RPG · Indie · Fantasy

Avadon: The Black Fortress
Shared: RPG · Indie · Isometric

Wasteland 2: Director's Cut
Shared: RPG · Turn-Based · Isometric

Clair Obscur: Expedition 33
Shared: RPG · Fantasy · Singleplayer

Baldur's Gate 3
Shared: RPG · Fantasy · CRPG

Hogwarts Legacy
Shared: RPG · Fantasy · Singleplayer

The World of Kungfu: Dragon and Eagle
Shared: RPG · Indie · Singleplayer

Might & Magic X - Legacy
Shared: RPG · Turn-Based · Fantasy

ATOM RPG: Post-apocalyptic indie game
Shared: RPG · Turn-Based · CRPG