How to Mod Baldur's Gate 3 with Universal Modder

To mod Baldur's Gate 3 with AI, start with one small change in a separate test save: an item description, a controlled stat adjustment or one visual resource. Universal Modder helps your agent investigate the project and prepare the files; the Baldur's Gate 3 Toolkit and an in-game check establish whether they work. Use the general tutorial for the backup and review process.

Can Universal Modder mod Baldur's Gate 3?

Yes. Universal Modder's knowledge base has six working BG3 projects covering data patches, wardrobes, equipment assets, load orders and diagnosis. Most run on Windows Patch 8-era installations; match your patch before reusing their files. Browse the BG3 field notes on GitHub.

For a first project, choose Larian's official Toolkit route. Its documentation covers resources, stats, spells, equipment and scripting. Add third-party extensions only when your chosen feature requires them. This walkthrough uses a local single-player test save. Larian's documentation describes the supported authoring tools; the compatibility FAQ covers other platforms and setups.

Compare Fallout 4's small data-plugin route if your goal is to learn record editing in another RPG; its tools and records are different. For a first editor task centered on a map instead, try the Age of Empires II DE scenario guide. Browse the game guides before choosing which authoring environment to learn.

What you need

• A Windows PC installation of BG3, with its exact patch and storefront recorded.
• The Baldur's Gate 3 Toolkit and BG3 Toolkit Data DLC. On Steam, the Toolkit appears under Tools; enable the Data DLC in the game's Properties. Official installation steps.
• An agent with Universal Modder installed, a project folder and a backup of any save you will use.
• A written goal and a small test list. Start with no unrelated mods, then add dependencies one at a time.

Some existing BG3 projects use LSLib Divine 1.20.4, and the larger wardrobe project uses Script Extender v32. A Toolkit-only experiment needs neither; add external tools only when your feature requires them.

Step-by-step

1. Create a clean project

Launch the Toolkit and point it at your actual game's Data directory. Select New Project, give the mod its own name and use a small test level. Larian's introductory workflow selects Act_1A_WLD → WLD_Crashsite_D. Keep your own project files backed up. Official project setup.

2. Ask the agent to inspect before editing

Give the agent the installation location, game patch, Toolkit version and intended change. Have it identify the relevant resource, current value, inherited values and any existing override. The CLI reference can help with discovery, but a scan is only a starting point. Review the proposed file list before any edits.

3. Change one resource in your own module

Use the Toolkit's Resource Manager to locate the resource, then choose Override In the Active Mod when an override is appropriate. Make one visible change and keep the original value in your notes. This creates a project-owned override instead of an untracked edit to installed data. Larian's override workflow.

For a stats task, ask the agent to show a matching vanilla example and explain inheritance before writing a patch. Do not accept a plausible-looking API or stat name without checking the installed data.

4. Package locally and verify in game

With your project loaded, open Project → Project Settings. Complete its Name, Description and Thumbnail, review dependencies and conflicts, and save. Choose Publish Local: the Toolkit creates a .pak and asks where to save it. This local action requires no authentication and does not upload to mod.io. Larian's packaging instructions.

Keep a copy with your source. With the game closed, place your test package in the documented Windows user mod folder:

%LOCALAPPDATA%\Larian Studios\Baldur's Gate 3\Mods\

Launch the intended game installation, open its Mod Manager → Installed tab and enable your mod with the checkbox to its right. Confirm its identity and required dependencies before loading the separate test save. Larian documents these controls in Playing With Mods. A package saved only in your source folder is not yet installed; if it is absent, recheck the output location and active Windows user before rebuilding.

Check the precise resource change, then repeat after restarting. Record the package revision and observed result. On the next iteration, close the game before replacing your own test .pak, and keep unrelated packages intact. Only expand the scope after the game check passes.

If you patch another mod, test the intended dependency order as a separate case: stats overrides must load after the definitions they change. Confirm each effect in play instead of assuming the patch applied.

5. Check removal before sharing

Exit the game, remove only your experiment from the test setup and confirm the original behavior with the pre-change save. Keep saves that depend on custom content separate. Before distributing your own files, use the release-check workflow and follow Larian's modding terms.

Example prompts

Adapt these starting requests to your installation. More planning and debugging variants are in the prompt library.

Use Universal Modder to inspect my BG3 Toolkit project. Record the game patch,
Toolkit version, target resource and current mod list. Propose one small,
reversible item change using documented data fields. Show the source example,
files to change, backup plan and in-game test before editing.

The game loads but my item override is missing. Compare the packaged resource,
module identity, inherited fields and active dependency order. Give me one
hypothesis and one test at a time. Do not rewrite the whole load order.

Mods people built

• A wardrobe generator: containers and reusable scrolls organized around compatible races and body types. The lesson is stable identifiers and a small pilot before a large generated catalog.
• Small gameplay patches: equipment and progression adjustments, with confirmed and still-unconfirmed effects tracked separately. This is a better starting scope than trying to generate a total conversion.
• Load-order recovery: keeping a large installation usable and recovering its configuration. Treat it as a troubleshooting reference, not a recommended beginner mod count.

Known issues and fixes

The load order resets or a removed mod returns. Preserve the original configuration and inspect your mod's metadata before making more changes. Two causes look alike: malformed package metadata, and subscriptions that restore removed content. Making the configuration read-only does not fully stop intermittent resets.

A campaign region hangs while the main menu works. Reproduce on a copied save and narrow the active set while retaining required dependencies. One known Act 2 hang came from a single mod's level layer, but similar hangs can have other causes; narrow the set before blaming one mod.

The package loads but the mechanic differs from the tooltip. Check inherited fields and observe the actual interaction. Keep the changed stat, expected result and observed result together in your report. The troubleshooting guide explains how to collect enough context for a useful fix.