Games like Birthright
Games like Birthright include Mount & Blade II: Bannerlord, Kenshi, Mount & Blade: Warband, We Who Are About To Die, and Kingdom Come: Deliverance II. We matched them by the tags players give Birthright on Steam (RPG, Simulation, Medieval, Sandbox, and Roguelite): closest matches first, and among equally close ones the better-known games.

Mount & Blade II: Bannerlord
Shared: Medieval · RPG · Sandbox

Kenshi
Shared: RPG · Sandbox · Simulation

Mount & Blade: Warband
Shared: RPG · Medieval · Sandbox

We Who Are About To Die
Shared: Simulation · RPG · Roguelite

Kingdom Come: Deliverance II
Shared: RPG · Medieval · First-Person

Graveyard Keeper
Shared: RPG · Simulation · Sandbox

The Scroll of Taiwu : Beyond The Dome
Shared: RPG · Sandbox · Simulation

Kingdom Come: Deliverance
Shared: RPG · Medieval · First-Person

The Witcher 3: Wild Hunt — Remastered
Shared: RPG · Atmospheric · Medieval

Crusader Kings III
Shared: Medieval · Simulation · RPG

KINGDOMS
Shared: Medieval · RPG · Simulation

Stardew Valley
Shared: RPG · Simulation · Sandbox

Potion Craft: Alchemist Simulator
Shared: Simulation · Medieval · Sandbox

Half Sword
Shared: Medieval · Simulation · Sandbox

鬼谷八荒 Tale of Immortal
Shared: Simulation · RPG · Sandbox

Medieval Dynasty
Shared: Medieval · Sandbox · RPG

Crusader Kings II
Shared: Medieval · Simulation · RPG

Mount & Blade
Shared: RPG · Medieval · Sandbox

The Bloodline
Shared: RPG · Medieval · Sandbox

Foundation
Shared: Simulation · Medieval · Sandbox

Mount & Blade: With Fire & Sword
Shared: RPG · Medieval · Sandbox

Totally Accurate Battle Simulator
Shared: Simulation · Sandbox · Colorful

Pax Dei
Shared: Sandbox · Medieval · RPG

龙胤立志传
Shared: RPG · Simulation · Strategy RPG