Blue Prince Mod Loader

A small, portable mod manager for Blue Prince. It installs MelonLoader for you, enables/disables mods without copying files (it links them into the game), fetches mods and their dependencies from the web, and can back up your saves. It ships with the Developer Cheat Menu mod built in.

Single-player game, no anti-cheat, so this is safe to run. Cheats can permanently change a save, so keep the save-backup feature on if you use them.

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For users

1. Download the latest release, unzip anywhere (keep BPModManager.exe and the Library folder together).
2. Run BPModManager.exe. It auto-detects your Blue Prince install via Steam.
3. Click Install MelonLoader (one time).
4. Tick a mod to enable it. Keep Dev Objects (Cheat Menu) is included; UnityExplorer downloads itself (and its dependency) when you enable it.
5. Click Launch Blue Prince.

Nothing is added to the game except MelonLoader and links to your enabled mods, and disabling removes exactly those.

Features

• MelonLoader install — one click; pulls the official release and sets it up.
• Link-based enable/disable — a mod's files are symlinked (or hard-linked, or copied) into the game's Mods/UserLibs, tracked so removal is exact. A banner tells you which method is in use and offers to enable symlinks (Developer Mode / admin) when useful.
• Fetch mods + dependencies — a mod can declare a GitHub release as its source; the manager downloads it and links its Mods\ and UserLibs\ contents. UnityExplorer works this way.
• Import what you already have — add loose .dlls, or adopt mods already in the game's Mods folder.
• Save & mod backups — back up the save folder (with restore + optional auto-backup before launch) and the whole mod library.

The built-in cheat menu

Keep Dev Objects un-hides Blue Prince's own developer cheat menu (Cheaters Failz), which the retail build deletes on load, and auto-shows the overlay so it appears just from having the mod enabled. In-game hotkeys (from the game's own overlay):

Key	Action		Key	Action
F	Floorplan Selection (spawn any room)		0	Free cam
I	Item Selection (give any item)		1/2	FOV down/up
R	Redraw floorplans		3/4	Move speed down/up
L	Luck Up		5/6	Camera tilt
			M	Camera recorder

See mods/KeepDevObjects for the mod's source and details.

Command line

The manager is also scriptable (any argument runs headless; no argument opens the GUI):

BPModManager status | diagnose
BPModManager enable <id> | disable <id> | add <path> | import-existing
BPModManager install-melonloader
BPModManager backup | backups | restore <name> | savedir
BPModManager backup-mods | restore-mods <name>
                                            [--game "C:\path\to\Blue Prince"]

Adding a mod

Create Library\<Id>\ with the mod's files and a modinfo.json, either bundled:

{ "id": "MyMod", "name": "My Mod", "version": "1.0", "description": "…",
  "files": { "Mods": [ "MyMod.dll" ], "UserLibs": [] } }

…or fetched from a GitHub release (the zip should contain Mods\/UserLibs\):

{ "id": "UnityExplorer", "name": "UnityExplorer", "description": "…",
  "source": { "githubRepo": "yukieiji/UnityExplorer",
              "assetName": "UnityExplorer.MelonLoader.IL2CPP.CoreCLR.zip" } }

Building

cd src
dotnet build -c Release
dotnet publish -c Release        # self-contained single-file win-x64 exe

Targets .NET 10. The built-in mod's source is under mods/KeepDevObjects (a MelonLoader IL2CPP mod, net6).

Disclaimer

Not affiliated with or endorsed by the developers or publisher. Uses content the developers left in the shipped game. Provided as-is; use on your own single-player copy at your own risk, and back up your saves.