Independent guides / Single-player PC modding

Universal Modder guides: mod PC games with AI

Learn to mod games with AI coding agents. Start small, follow the source, and test what you build.

Start with installation →Explore game mashups

What is AI game modding?

You describe a change to a coding agent, which investigates the game and helps build a mod. The work still involves choosing a modding route, preparing assets and checking the result in the running game.

Universal Modder is an MIT-licensed open-source project that supplies agent skills, the Python um CLI and shared field notes. Its documented workflow moves from game reconnaissance and save backups to a working slice, assets and in-game verification. Our guides explain that workflow for single-player games you own.

3 steps to your first mod

01 / PREPARE

Connect your agent

Choose the install route for your coding agent and check the README requirements.

02 / DEFINE

Ask for one change

Let the agent identify the game and search prior notes. Back up saves before making changes.

03 / VERIFY

Try it in the game

Build one working slice, check the real behaviour, then expand the mod and record what you learned.

From the project's showcase

These examples are described in the README. They are project reports; we have not run them ourselves.

  • Minecraft × GTA V: Steve glides through Los Santos, the Nether spreads across it, and Minecraft mobs fight the police.
  • Halo × Minecraft: the Warthog appears in Minecraft.
  • World at War × Minecraft: the showcase features a flamethrower and zombies.
  • Terraria — Fal Arsenal: new weapons, enemies and a Drone Mothership boss, with sprites generated through fal.
  • Age of Empires II DE — San Franciscans: a civilization with a Robotaxi, Delivery Drones and a Transamerica Pyramid wonder.
  • Minecraft inside GTA V: camera, ground and event exchange connects the games; colour and depth combine their frames.

Read how a game mashup is built →

Choose your next step

02 / Build a mashup

Merge games with AI

Choose between a content port, a two-game bridge and a rebuilt simulation.

03 / Make assets

Set up your fal key

Connect fal for asset generation, or explore the local ComfyUI image route.

06 / Troubleshoot

Fix a setup error

Read maintainer replies, reporter workarounds and unresolved reports.

07 / Check your tools

Windows and WSL

Separate general requirements from example-specific build dependencies.

08 / Minecraft

Mod Minecraft with AI

Compare six contributor reports, exact versions and verification limits.

09 / GTA V

Minecraft in GTA V

Understand the official story-mode passthrough and its known limits.

Frequently asked questions

What is Universal Modder?

Universal Modder is an MIT-licensed open-source project combining agent skills, a Python CLI, asset tools and shared field notes for modding PC games you own.

How do I mod games with AI?

Choose an agent install route, check the requirements, then describe a small change. The project workflow searches existing notes, identifies the game, backs up saves, builds a slice and verifies it in the running game.

Which coding agents are documented?

The README lists Claude Code, Codex, Gemini CLI, VS Code / Copilot, Cursor and OpenCode, plus Skills only and Anything else installation routes.

Do I need a fal API key?

A fal key is used for fal asset generation. For images without that key, the README describes um comfy with a local ComfyUI server.

Are these mods independently tested here?

No. The examples are project reports and the guides follow the supplied research snapshot. We have not tested every game or agent setup.

What kind of modding do these guides cover?

These guides cover single-player modding of games you own. Start with a safe setup, back up saves and verify the result in the actual game.