Moddable features from a single file (like characters or attacks)

I’m currently making an RPG in Unity and I want to have all attacks (and characters) in files next to the .exe in a Assets (or Mods) folder.

I want the file format to be like *.atk or *.chr and inside the file you set parameters like the attack name or the attack type.

I also wanted to add hardcoded functions that you call inside the mod file like DoDamage() or createSprite() which basically lets the modder tell the game what the attack does.

I’m fairly new to Unity so does anyone know how I can incorporate this?

Unity is pretty bad for this kind of thing and doesn’t have very good modding support out of the box. Depending on the type of data you want to load, as some things can be loaded at runtime reasonably easily. For example if you want to load text and number data or simple images there are ways of doing it. It becomes much more complicated if you want to load meshes/animations/prefabs etc.