Replace game files with a content pack

Ship a texture, video, config file or map that replaces or adds to the game's own files — no code required.

The recipe

A content mod is a package with no entry: just mod.json and a files/ folder that mirrors the game's own folder structure.

hd-loading-screens/
├── mod.json
└── files/
    └── Content/T3/Bitmaps/Loading1.dds

{
  "format": 1,
  "id": "hd-loading-screens",
  "name": "HD Loading Screens",
  "version": "1.0.0",
  "authors": ["Your Name"],
  "description": "Sharper loading screens.",
  "tags": ["graphics"]
}

files/Content/T3/Bitmaps/Loading1.dds replaces <game folder>/Content/T3/Bitmaps/Loading1.dds while the mod is enabled, and the launcher restores the original file when it is disabled. Get the path exactly right (case does not matter, but every folder and the file name must match); Content and texture packs lists what usually goes under files/, and how the backup and restore mechanics work.

Then validate and pack it:

python tools/t3mod.py validate hd-loading-screens/
python tools/t3mod.py pack hd-loading-screens/

Drag the resulting .t3mod onto the launcher, enable it, and check that the file changed in the game folder; disable it again and check that the original is back.

An alternative for textures: textures/

files/ replaces a loose file on disk. Some textures instead live packed inside the game's .ibt bundles; a textures/<name>.dds entry replaces one of those by resource name instead of by path (experimental — needs the exact name, a supported DXT/A8R8G8B8 format, and a power-of-two size). See Content and texture packs (the "textures/" section) and tools/assets/t3texpack.py list to find names.

Watch out for

• Only your own work. Never put a game file — original or edited — into a package, even a single texture. Packages are shared with other players; what you ship must be yours (see CONTRIBUTING.md).
• Two mods, one file. If another enabled mod also provides the same path, whichever is later in the load order wins; there is no merging. Use mod.json's conflicts if your pack genuinely cannot coexist with a specific other one (see Play well with other mods).
• Nothing under System/. Code goes through entry so it shows up in the load order and in crash reports; files/ refuses paths there.

Reference

• Content and texture packs: the full mechanics of files/ and textures/.
• Mod packages: the manifest format and how the launcher applies content.
• Packaging: tools/t3mod.py in full.