Baldur's Gate 3 Script Extender
What Baldur's Gate 3 Script Extender is
Baldur's Gate 3 Script Extender adds Lua and Osiris scripting support for Baldur's Gate 3 mods. A mod can enable Lua with a feature flag and load bootstrap scripts for the client and server. The extender maintains separate Lua states for the game server and each client, and provides a console for Lua code and registered commands. Configuration options include Lua and Osiris debugger interfaces with configurable listening ports. Logging settings can write Osiris activity, runtime output, story compilation, and compilation errors to files. An EnableAchievements option can turn achievements back on in modded games. After a crash, SendCrashReports is enabled by default and uploads minidumps to a crash-report collection server. Installation instructions call for extracting DWrite.dll into the game's bin directory. The extender updates when the game launches, but does not run on versions older than patch 5; new releases target the latest game version. It supports Windows and Linux via Proton. It is free to obtain under a license with a Commons Clause condition restricting sales of the software or substantially derived products and services.
Who it suits
The Script Extender is for Baldur's Gate 3 mod creators who want to use Lua or Osiris scripts. Its configuration and installation details are relevant for people prepared to work with mod files and game-version requirements.
What it does well
- Adds Lua and Osiris support for mods.
- Includes a console for Lua and registered commands.
- Offers debugger and logging configuration options.
- Can re-enable achievements in modded games.
- Updates when the game launches.
What to know first
- Requires Baldur's Gate 3 patch 5 or later.
- New releases target the latest game version.
- Crash minidumps upload by default after a crash.
- License restricts certain sales.
Limits
The extender does not run with game versions older than patch 5, and new releases target the latest game version. It is free to obtain, but the Commons Clause condition restricts selling the software or substantially derived products and services.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Baldur's Gate 3 Script Extender | Windows/Linux Proton modding tool · requires Baldur's Gate 3 · version-specific compatibility | Free |
As github.com lists them, read 15 Oct 2026. The maker's own page has the final word.
Getting started
- Open the project website.
- Use Baldur's Gate 3 on Windows or Linux through Proton.
- Extract DWrite.dll into the game's bin directory.
- Configure the mod file and Lua feature flag if the mod uses Lua.
- Launch the game to download and apply an extender update.
Verdict
The extender offers scripting, debugging, and logging capabilities for Baldur's Gate 3 modding. Check the game-version requirement and license condition before using or distributing related work.
Questions
How much does Baldur's Gate 3 Script Extender cost?
It is free to obtain; the listed plan is free.
Which platforms does it support?
It supports Windows and Linux through Proton.
Which game does it work with?
It supports Baldur's Gate 3 and requires patch 5 or later.
What scripting does it add?
It adds Lua and Osiris support. Mods can enable Lua with a feature flag and load client and server bootstrap scripts.
Does it update automatically?
The release FAQ says it updates when the game launches by downloading and applying an update.
Can the software be sold?
The license includes the MIT License and a Commons Clause condition that excludes selling the software or substantially derived products and services.
Facts from Baldur's Gate 3 Script Extender's own pages
- Achievements
- The default configuration re-enables achievements for modded games. · github.com, 15 Oct 2026
- Automatic updates
- The updater downloads and applies the matching extender when the game launches, so GitHub releases represent updater changes rather than every extender build. · github.com, 15 Oct 2026
- Build requirements
- Developers are instructed to run first-time-setup.bat from an MSVC x64 Native Tools command prompt and then use Visual Studio. · github.com, 15 Oct 2026
- Client and server
- The extender maintains separate Lua states for the game server and each client. · github.com, 8 Oct 2026
- Console
- The extender provides an interactive console that executes Lua and can invoke Osiris functions. · github.com, 15 Oct 2026
- Console limitation
- The community installation guide says PlayStation and Xbox have no official Script Extender support. · wiki.bg3.community, 15 Oct 2026
- Crash reports
- The SendCrashReports option defaults to true and uploads minidumps to a crash report collection server after a game crash. · github.com, 8 Oct 2026
- Debugger ports
- The documented default ports are 9999 for Osiris debugging and 9998 for Lua debugging. · github.com, 15 Oct 2026
- Debugging
- Configuration supports console logging, runtime logs, compilation logs, an Osiris debugger and a Lua debugger. · github.com, 15 Oct 2026
- Documentation depth
- The Lua API document is about 1,957 lines and includes examples and function behavior details. · github.com, 15 Oct 2026
- Events API
- Lua scripts can subscribe to engine events with priority and one-shot options. · github.com, 15 Oct 2026
- Game data APIs
- Documented modules cover entities, stats, resources, localization, audio, templates, level operations and math. · github.com, 15 Oct 2026
- Game version limit
- The FAQ says the extender does not run on game versions older than patch 5 and new versions are released for the latest game version. · github.com, 8 Oct 2026
- Independent installation support
- BG3 Wiki says the extender can be installed manually or through Baldur's Gate 3 Mod Manager and updates itself at game startup. · bg3.wiki, 15 Oct 2026
- Independent praise: ecosystem importance
- A BG3 modding guide presents the extender as the foundation for writing mods with Lua and Osiris scripting. · wiki.bg3.community, 15 Oct 2026
- Independent praise: mod compatibility
- PC Gamer describes the extender as Patch 8 verified and often required for many other Baldur's Gate 3 mods. · pcgamer.com, 15 Oct 2026
- Installation
- The official release instructs users to extract DWrite.dll into the game's bin directory. · github.com, 15 Oct 2026
- Intended users
- The documentation describes using the extender in mods, including setting a mod configuration file and Lua feature flag. · github.com, 8 Oct 2026
- Licence
- The repository combines an MIT licence with a Commons Clause condition that excludes selling the software or services whose value substantially derives from it. · github.com, 15 Oct 2026
- License
- The repository license includes the MIT License and a Commons Clause condition that excludes selling the software or substantially derived products and services. · github.com, 8 Oct 2026
- Limit: crash causes
- The official troubleshooting guide says crashes commonly result from game-version incompatibility or incompatible mods after a game update. · github.com, 15 Oct 2026
- Limit: update breakage
- A Reddit discussion reports that automatic updating to version 33 produced an error and users needed developer mode to select version 32. · reddit.com, 15 Oct 2026
- Linux support
- The community installation guide documents Windows and Linux/Steam Deck use through Proton, with extra launch options required. · wiki.bg3.community, 15 Oct 2026
- Logging
- Configuration options can log Osiris activity, runtime output, story compilation, and compilation errors to files. · github.com, 8 Oct 2026
Where Baldur's Gate 3 Script Extender stands on Freedom251
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