reone is a free and open source game engine, capable of running Star Wars: Knights of the Old Republic and its sequel, The Sith Lords. We aim to provide an engine that can be used to:

• Play KotOR and TSL from beginning to end
• Create mods that drastically change the gameplay or improve the visuals

The project is at a mid-stage of development: most engine subsystems have already been implemented, while game mechanics are actively being worked on. See project roadmap for our long-term plans.

reone adheres to clean-room design principles. We do not condone the use of decompilation - instead, we rely on publicly available information (e.g., file format specification provided by BioWare) and our own observations of the game and its resources.

We do not distribute copyrighted materials - instead, we require our users and developers to obtain a legal copy of the game.

Lastly, reone is explicitly a non-commercial project: we do not seek to gain profit, neither through donations nor other means.

To install reone, either download a prebuilt executable from the releases page, or build it from source. Building it requires a modern C++ compiler and a set of free and open source libraries. See detailed instructions for your operating system here.

reone is being developed and tested against unmodded Steam versions of both KotOR and TSL. Compatibility with any other version is not guaranteed, although GOG and retail versions should work with no or minor modification.

Install Visual C++ Redistributable to run prebuilt Windows executables.

Use launcher application to choose a game directory and launch reone. Alternatively, reone can be started from the command line: reone --game GAME_DIR

reone can be configured via the launcher, the configuration file or the command line.

Configuration file, named "reone.cfg", must be located in the current directory. See complete list of program options here.

reone is open to potential contributors. Contact us on this Discord server if you're interested in taking a particular task from the roadmap.

Developer resources:

• Project Architecture
• Code Style
• Testing
• Tooling
• Knowledge Database

reone is not the only project aiming to reimplement the Odyssey engine - there are at least four alternatives:

• xoreos - a reimplementation of BioWare's Aurora engine and its derivatives
• KotOR.js - a remake of the Odyssey engine written in JavaScript
• The Northern Lights - a Unity-based reimplementation and a level editor
• KotOR-Unity - another Unity-based reimplementation

In contrast, this is what reone offers:

• KotOR and TSL only, unlike xoreos, which aims to reimplement all of Aurora engine games - codebase is lighter and development is more focused
• Written in C++ - industry standard language, faster than the JavaScript implementation
• Custom game engine based on SDL 2 and OpenGL 3.3 - does not depend on Unity, which is a proprietary software with a learning curve of itself