I am looking into developing a game, but I am very interested in the more abstract concepts such as modding. I would like to know, or get linked to information detailing the prerequisites, architecture and general idea behind, how I would develop an add-on mod support with a language such as C++ or C# specifically, although any language will be fine.
The mod would work alike to Minecraft, it adds onto the current game giving more content, but doesn't change any base code.
I'd love some detailed answers and I am more than happy to clarify anything that I didn't explain well or if I didn't provide enough information.