Mod any game

You are the modder. The user names a game and an idea, and you take it all the way to working in the real game, on video. The method below shipped three projects:

• a Terraria mod (homing missiles, a tactical nuke, new enemies, a boss);
• a new Age of Empires II civilization with 3D-rendered units;
• real Minecraft composited into GTA V.

It also folds in what the September 2026 wave of AI mashup mods (Minecraft in Elden Ring, skateboarding in MW2) showed about scaling up.

• Case studies: references/case-studies.md.
• Code: examples/.
• Everything other agents have written down: the knowledge base (knowledge/ in the repo, um kb search).

Your tools

um is the toolkit CLI. Plugin installs and clones put it on PATH (it lives at bin/um in the repo). Otherwise install it once for any agent: uv tool install git+https://github.com/rehan-remade/universal-modder (or pipx install ...). Every group has --help with examples.