CASC and MPK explorer

See what is inside the game.

Rusty Demon opens the archives Blizzard games ship in. Browse every file, search by name, preview models and textures, and export them for Blender. It runs on Windows, macOS, Linux and Steam Deck.

Download Source on GitHub

Free and open source. For personal and educational use.

Rusty Demon on Windows: a file tree on the left, search results for Sylvanas in the middle, and her World of Warcraft model in the 3D preview on the right

Games

Point it at an install folder

Choose File, Open Game Directory and pick the folder the game lives in. Rusty Demon works out which game it is. The tag beside each name is the product code the app shows once the game is open.

  • World of Warcraft

    wow

    Models in the 3D viewer, BLP textures, and export of models with bones and animations.

  • Diablo IV

    fenris

    Battle.net and Steam installs. Textures, skill data and movies preview in the app.

  • Diablo III

    d3

    Every file named from the game's own tables. Models, textures, text, and animated export.

  • Diablo Immortal

    anbs

    Reads the MPK packages this game uses. Meshes open painted with their textures.

  • StarCraft II

    s2

    Textured models in the 3D viewer, DDS textures, and export with bones and animations.

  • StarCraft

    s1

    Unit and building sprites preview as sheets of frames.

  • Diablo II: Resurrected

    osi

    Opens the newer storage layout, with files spread over more than one data folder.

  • And more

    heroprohs

    Heroes of the Storm, Overwatch and Hearthstone open for browsing, search and raw export.

Preview

Look before you export

Select a file and the right panel shows it: a model you can turn, a texture, a sprite sheet, or the readable form of a data file. Each kind of file brings its own export buttons.

A Diablo Immortal barbarian armour mesh, textured, in the 3D preview on macOS
Diablo Immortal meshmacOS
A StarCraft unit sprite sheet in the preview panel on Steam Deck
StarCraft spriteSteam Deck
A Diablo IV texture in the preview panel
Diablo IV texture
Diablo IV skill data shown as readable text with its formulas
Diablo IV skill data

Export

Into Blender with bones and motion

Models from World of Warcraft, Diablo III and StarCraft II export as glTF, a format Blender opens directly. The file carries the mesh, its textures, the skeleton, and the game's animations as separate actions.

Models

glTF with skeleton and animations, or plain OBJ with a material file when you only need the shape.

Textures and sprites

PNG, decoded from BLP, DDS and the Diablo texture formats.

Movies and everything else

Diablo IV movies export as Bink video. Any file at all exports raw, exactly as stored.

Steam Diablo IV

The Steam build opens too

Diablo IV on Steam stores its files in a different layout from the Battle.net version, one that older archive tools were written before. Rusty Demon reads both and tells them apart on its own.

Battle.netSteam
Starts from.build.infoData/.build.config
Archive filesdata.NNNmeta.dat and payload.dat pairs
Where a file isLooked up in index filesPacked into the file's own key

Download

Get Rusty Demon

Pick your system. Each link goes to the latest release.

WindowsInstaller (.msi) macOSDisk image (.dmg) Linux and Steam DeckArchive (.tar.gz)

First launch

The installers are not code-signed yet, so the system warns once.

Windows: on the SmartScreen prompt choose More info, then Run anyway.

macOS: right-click the app and choose Open, then Open again.

Check the download

Every release lists a SHA-256 checksum for each file and carries GitHub's signed record that it was built from the tagged source. With the GitHub CLI:

$ gh attestation verify <file> \
    --repo HoldMyBeer-gg/rustydemon

Build it yourself

With the Rust toolchain installed:

$ git clone https://github.com/HoldMyBeer-gg/rustydemon
$ cd rustydemon
$ cargo run --release -p rustydemon