LOOT is a plugin load order optimisation tool for TES III: Morrowind, TES IV: Oblivion, TES V: Skyrim, TES V: Skyrim Special Edition, Skyrim VR, Fallout 3, Fallout: New Vegas, Fallout 4 and Fallout 4 VR. It is designed to assist mod users in avoiding detrimental conflicts, by automatically calculating a load order that satisfies all plugin dependencies and maximises each plugin's impact on the user's game.

LOOT also provides some load order error checking, including checks for requirements, incompatibilities and cyclic dependencies. In addition, it provides a large number of plugin-specific usage notes, bug warnings and Bash Tag suggestions.

Although LOOT is able to calculate the correct load order positions for the vast majority of mods without any user input, some plugins are designed to load at certain positions in a load order, and LOOT may be unable to determine this from the plugins themselves. As such, LOOT provides a mechanism for supplying additional plugin metadata so that it may sort them correctly.

LOOT is intended to make using mods easier, and mod users should still possess a working knowledge of mod load ordering. See Introduction To Load Orders for an overview.

Releases are hosted on GitHub, and snapshot builds are available on Artifactory. The snapshot build archives are named like so:

loot_<last tag>-<revisions since tag>-g<short revision ID>_<branch>-<platform>.7z

Refer to .github/workflows/release.yml for the build process.

The GitHub Actions workflow assumes that CMake, curl, gettext, Git, Inno Setup 6, Python, Visual Studio 2019 and 7-zip are already installed.

The GitHub Actions workflow assumes that you have already cloned the LOOT repository, that the current working directory is its root, and that the following applications are already installed:

• cmake v3.6+
• curl
• git
• python and pip
• wget

(The list above may be incomplete.)

Not all LOOT's features have been implemented for Linux builds. Issues labelled linux on LOOT's issue tracker cover such missing features where they can be implemented.

LOOT uses the following CMake variables to set build parameters:

You may also need to set BOOST_ROOT if CMake cannot find Boost, and Qt6_ROOT (e.g. to C:/Qt/6.4.1/msvc2019_64) or Qt5_ROOT if CMake cannot find Qt.

The documentation is built using Sphinx. Install Python and make sure it's accessible from your PATH, then run:

pip install -r docs/requirements.txt
sphinx-build -b html docs build/docs/html

Alternatively, you can use Docker to avoid changing your development environment, by running docker run -it --rm -v ${PWD}/docs:/docs/docs -v ${PWD}/build:/docs/build sphinxdoc/sphinx:4.2.0 bash to obtain a shell that you can use to run the two commands above.

Packaging scripts are provided for creating an installer on Windows and compressed archives on Windows and Linux.

Run the scripts/installer.iss Inno Setup script to build an installer executable in the build folder. If the unofficial Korean, Swedish and Simplified Chinese Inno Setup translation files are installed alongside the official translation files, then the installer script will also offer those language options. If they are not found, the installer will be built without them.

Building the installer will always build a 32-bit installer executable. The installer will run in 32-bit mode by default and install the 32-bit MSVC redistributable, even if it installs a 64-bit build of LOOT. To build an installer that runs in 64-bit mode and installs the 64-bit MSVC redistributable, pass -DMyAppIs64Bit when building the installer.

The archive packaging script requires Git, and on Windows it also requires 7-Zip, while on Linux it requires tar and xz. It can be run using python scripts/archive.py, and creates an archive for LOOT in the build folder. The archives are named as described in the Downloads section above.

The archive packaging script calls windeployqt.exe when run on Windows: it must be accessible from your PATH.