1. Introduction

While .gd is good for simpler code and its faster to ship. Using .pck brings some advantages to the table talked here

On this guide you will need godot installed, and you also will need to create a new project(this is needed to export to a pck)

2. Setup

Similar to the gd files in a folder a pck mod structure is something like this:

   mod/ <- this needs to be exactly called mod.
     your_mod/
          your_mod.gd <- this should always be called the name of your parent folder
          your_mod.json <- this should always be called the name of your parent folder

The reason why this is the needed structure comes down to the way the modloader loads pck folder

If you know a bit about godot, you would know that godot offers a virtual file system(res://) for the games to store their assets, scripts, scenes, etc.

And godot offers a way for us to load external resources to that res:// root folder. What kind of black magic they do?

Copypaste :)

So using our example when the loader loads the pck what its doing is this:

Before loading:

  res://
    scenes/
    scripts/
    ...

After loading:

  res://
    ...
    mod/
      your_mod/
          your_mod.gd
          your_mod.json

Yeah, super difficult i know. After this little setup you are good to go. Because duckloader treats gd files and gd files on the pck the same way.

If you made a gd files folder, you just adapt the structure for this and you are mostly done. We just need to export it as a pck.

3. Exporting

You are almost there, now we just need to export.

The process of exporting is simple, if you didnt make a godot project for the mod yet.

Open godot
|
New project(the name is irrevelant) 
|
Import the files and folders to it.

And when you done and want to export. This is going to be a bit different for each OS, I will assume you are using windows.

Project(on top left side)
|
Export
|
Add(This is to create the preset for the export)
|
Windows
|
Export PCK/Zip

Then choose the location for the pck. The name for now NEEDS to be the same as the root on the file structure. If the name is mispelled expect undefined behavior.

Conclusion

Thats it, you successfully made a pck mod ready to distribute. There is no changes on the code.

The pck behaves as game code, so everything you can do on godot, you can do here too.