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Use Decompiled Bannerlord sources with AI

DO NOT USE GITHUB'S COPILOT. IT'S TOTAL CRAP/SCAM. USE CURSOR OR CLAUDE INSTEAD.

THIS IS A HUGE PRODUCTIVITY BOOST

This method gives the AI full access to the Bannerlord source to explore and analyse, and allows me to save up to 80% of the time I previously spent searching for where and how things are implemented. Actually I am lying. It saves me 100% of time. I don't remember when I searched something in the BLs code.

Step 1 — Decompile BL files using the script

The batch script calls ilspycmd for every Bannerlord DLL. Install that tool first so it is available from the command line.

Install ilspycmd

  1. Install the .NET SDK (includes the dotnet CLI). Current ilspycmd on NuGet targets .NET 10; use an SDK that can run that tool.
  2. Install the global tool (NuGet: ilspycmd, ILSpyCmd README):
dotnet tool install --global ilspycmd
  1. Make sure the global-tools folder is on your PATH (required for ilspycmd to work in cmd/PowerShell):
OS Default install path
Windows %USERPROFILE%\.dotnet\tools
Linux / macOS $HOME/.dotnet/tools

On Windows, the .NET SDK installer usually adds that folder to PATH. If a new terminal still says ilspycmd is not recognized, add %USERPROFILE%\.dotnet\tools to your user PATH and open a new terminal.

On Linux / macOS, add $HOME/.dotnet/tools to PATH in your shell profile (for example ~/.bashrc or ~/.zshrc) if it is not already there. See dotnet tool install.

  1. Verify:
ilspycmd --version

To update later: dotnet tool update --global ilspycmd.

Run the decompile script

Get script here.

(Copy from Noxix Targaryen's script)

Adjust destination folder in the script based on your environment. Set BANNERLORD_GAME_DIR to your game install (the folder that contains bin\Win64_Shipping_Client).

Step 2 — Create BLSource in your project folder

Inside your mod project directory, create a dedicated folder BLSource

Step 3 — Copy decompiled files into BLSource

Move the output from Step 1 into BLSource.
Keep the original folder structure so AI can navigate namespaces naturally.

Step 4 — Exclude folder from project in Visual Studio

Right-click BLSource in Solution Explorer -> Exclude From Project.

This keeps the files visible on disk (and to AI) without polluting your build — VS won't try to compile them.

Step 5 — Done

Your project tree now contains readable BL source as a silent reference layer. No build errors, no extra dependencies.

Step 6 — Ask AI to explore BLSource

AI indexes local files in your workspace. Example prompts:

  • "In /BLSource, how does MissionAgentSpawnLogic decide spawn positions?"
  • "Find the base class for campaign behaviors in /BLSource and explain the tick pattern."
  • "How does settlement loyalty decay work in /BLSource?"

Looks like this:

Github Copilot

UPDATE 2026-05-25
Copilot in VS Studio is crap. Better solution is to use Cursor/Claude.