Mod Bannerlord with AI: a Borderlands 2 conversion

This Bannerlord AI mod report concerns a personal-use Borderlands 2 total conversion, marked in-progress. Bannerlord remains the host for battles and campaign systems; imported personal content and C# recreate parts of the donor game’s rules. The source credits Claude Code and reports roughly 180 unattended recorded test runs, but does not establish a finished, fresh-install conversion. Source: total-conversion field note.

Setup and module route

The documented build is v1.4.8.119303, Steam, Windows 11, with the Modding Kit build 24575232 and optional Bannerlord.Harmony 2.4.2. The module uses SubModule.xml, ModuleData XML / XSLT and a C# net472 SubModule built with the .NET 8 SDK. Tools named in the note include Python 3.10, Blender 4.2, Ghidra 12.1.4, ilspycmd 9.1 and UE Viewer (umodel). Those are the contributor’s tool versions, not a compatibility matrix. Source: setup and route.

The chosen route ports content and expresses Borderlands rules through Bannerlord modules. It does not run both games together. The report describes troops on their own skeletons, creatures as mounts, crossbow-class guns, recharging shields, elemental effects, loot and UI. Only Harmony was adopted from the libraries investigated, and it has non-Harmony fallbacks. Source: conversion approach.

Assets, races and combat: in-progress evidence

The in-progress editor-free assets note describes custom readers and writers for .tpac and .rdc instead of repeated editor interaction. Package round trips and validators establish some format facts; they do not prove every asset in a long campaign. It records a 64-bone limit and warns against loading larger custom skeletons. The shield clip-partner fix and hit guard were staged or compiled but not run in-game. Source: editor-free Bannerlord assets.

The in-progress races note distinguishes humanoid agents, quadruped mounts and hidden-rider creature fighters. Custom animation sets must actually load; clips need the correct skeleton, flags and follow-ups. A visible body alone does not establish movement or combat. Source: custom races and creatures.

The in-progress combat note implements firearms through the crossbow class and treats ammo, damage, morale and AI as separate contracts. It reports reinforcements dealing no damage when raw spawning omitted initial weapon wielding and the alarmed state; mirroring normal troop setup fixed that case. Source: combat, damage and guns.

This is a personal-use report. Its game-derived assets stay local to the owner’s installs. Game files and ripped assets must not be redistributed; no asset download or extraction instructions are provided here. Sources: conversion assets policy, contribution policy.

Native crashes and hangs

The in-progress native crashes note separates evidence seen in-game, measurements, static analysis and hypotheses. Its offsets apply only to v1.4.8.119303. The headings below preserve searchable symptom wording from that note; the explanations summarize its linked asset findings. No untested guard is presented as a verified fix. Sources: native crash investigation, asset gotchas.

Access violation 3 to 4 s after a custom-race agent spawns, when it starts to move (+0x759c47).

Movement-slot clips lacked the required movement-distance parameter. The asset note fixes the clip data by action slot and excludes idle clips from movement slots. Sources: native symptom, asset cause and fix.

Crash about 7 s after a non-human race spawns (+0x584fec).

A placeholder face had no morph targets but inherited human deform keys. The asset note clears deform keys for the no-facegen race. Sources: native symptom, asset cause and fix.

About 1 in 3 battles crash at deployment end (+0x6feb3f).

The project’s probe passed an invalid action index into a native lookup. The asset note adds an index check before action-indexed API calls. Sources: native symptom, asset cause and fix.

Crash at the first melee contact or on a blocked reaction (+0x66d5a9).

Melee clips were missing weapon-balance registration because their paired-animation strings had been cleared. The asset note restores self-naming paired strings. Sources: native symptom, asset cause and fix.

Process dies at start-up in "Initializing items" with fast-fail 0xc0000409, even after rolling back.

Clip names exceeded the native fixed-length buffer. The asset pipeline caps names at 63 characters and rejects longer names before installation. Sources: native symptom, asset cause and fix.

Crash when an agent on a custom skeleton raises a shield (+0x669cc5).

The clip writer had erased the blend partner. Preserving partner and continuation data passed offline checks, but the staged fix was not installed or run in-game. Sources: native symptom, asset cause and fix.

Crash at game start (+0x730550) after adding a sound-event line to project.mbproj.

The project file referenced a missing or transformed sound XML file. The native loader needs an existing raw XML file; XSLT is not a substitute at this entry. Sources: native symptom, asset cause and fix.

Hard freeze (no crash report, CPU busy) on the first hit on a jaw, toe, heel, cape, claw or robot arm.

Hit capsules on bones without IK joints led a worker into an endless parent walk. The asset note proposes correcting skeleton data and describes a compiled Harmony guard that remaps the hit to a safe ancestor. That guard was not yet run in-game. Sources: native symptom, asset cause and fix.

Verification limits and how to start

The report combines recorded game runs, binary round trips and offline validation. Its clean converter has only had dry-run and self-test checks, not a real end-to-end conversion. Audio was not heard by the agent. Long campaign behaviour, several staged fixes and updated game builds remain open. Source: verification and open questions.

Begin with Install Universal Modder and adapt the personal content-port or mashup prompt templates. Ask for single-player only, back up saves and files, and prove one small slice on your exact build. Use how to merge two games with AI to choose a route and Errors for setup or game-specific symptoms. Source: mod-any-game workflow.

Frequently asked questions

Is this Bannerlord conversion finished?

No. The game note and its companion technique notes are in-progress. Recorded tests demonstrate parts of the project, but a clean end-to-end converter run, several staged guards and long-session behaviour remain unverified.

Which Bannerlord version do the crash offsets describe?

The notes use v1.4.8.119303 on Steam and Windows 11. Their native offsets become stale after an update; do not apply them to an unknown build.

Can I redistribute the Borderlands 2 assets?

No. The report is a personal-use project based on the owner's local installs. Game files and ripped assets must not be redistributed, and this guide provides no asset downloads or extraction walkthrough.

Will this work online?

Online use is out of scope. The report concerns single-player only and does not establish multiplayer or anti-cheat safety.