Crusader Kings III Modding on OpenMods

Paradox grand strategy with first-class mod support

Crusader Kings III (2020) is Paradox Development Studio's medieval dynasty simulator and a direct continuation of the modding-friendly tradition the studio has cultivated since EU3. Modding is a sanctioned feature, Paradox ships with both Steam Workshop and Paradox Mods integration, the launcher includes mod-list management, and the game's data files are deliberately exposed as moddable scripts.

The CK3 modding scene is enormous. Game rules, character traits, events, religions, cultures, entire alternative histories (Fallen Eagle, Princes of Darkness, A Game of Thrones), and visual overhauls all live on Workshop or Paradox Mods.

The toolchain

• Steam Workshop / Paradox Mods: primary distribution channels. Both are sanctioned; Workshop is the more active for PC users.
• Paradox Launcher: Paradox's launcher (which sits between Steam and the game). Handles mod activation, load order, and account linking for Paradox Mods.
• Script files: CK3's content is defined in .txt script files under game/. Most mods are script-only, no compiled code needed.
• CK3 Tiger: community linter that catches script errors before in-game testing.

What you'll find on OpenMods

CK3's mod community lives primarily on Workshop. GitHub hosts source for the larger overhauls (because they have many contributors), but most users discover and install through Workshop. OpenMods catalogues GitHub-hosted CK3 mods, typically larger total conversions and toolchain projects.

Practical notes

• Ironman + mods don't mix. Most mods disable achievements via the "checksum" mechanism. CK3 distinguishes "Ironman-compatible" mods (a small set) from everything else.
• The launcher manages load order. Drag to reorder. Later mods override earlier ones for any data they touch.
• Major DLCs interact with mods. Each DLC adds new game systems (Royal Court, Tours and Tournaments, Roads to Power, etc.). Mods may or may not be aware of newer DLC content. Read compatibility notes carefully.
• Total conversions are common. Unlike most games, CK3's modding scene is dominated by full alternative-setting conversions (Game of Thrones, Lord of the Rings, Warhammer Fantasy). Picking one is itself a major decision.