From Star Ruler
The first step toward making any mod is to create a folder within the Mods/ folder in your Star Ruler install folder or in your user files area. Give this folder a unique name, and inside it create a text file: "modinfo.txt"
This text file has a key Key:Value pairs you can set, all of which are optional:
Name: The name shown to the user for this mod. Defaults to the name of the folder. Derive from: The mod from which to derive from. Valid values are "none" for no overriding, "base" for the base game (Default), or the name of another mod (folder name, or display name).
When a mod derives from another mod, most data files will load from the first mod that has the given file in a matching folder. For example: You create a mod 'Foo' which derives from the base game, and you wish to completely rewrite the research system. Within /Mods/Foo/, you create the folder and file /Game Data/Technologies/research.txt. Since "/Game Data/Technologies/research.txt" is both in Foo and the base game, it will only load Foo's copy.
Only files automatically loaded by the engine follow this pattern, with the exception of: Materials/materials.txt - This file is loaded for each mod, starting with the top mod (Foo), then each base mod. Models/models.txt - Like materials, it is loaded for each mod.