The somewhat misnamed "MGF Rules System" consists of a single "rule"--"go with whatever you think will have the most MGF potential" and steps for character building.
Characters have only narrative tags--brief phrases that describe them. First, establish a background. Then identify five things your character does well, five things they do poorly, five obvious things about them, five secret things about them, and three things they believe are true. Then, they get a favorite possession. And that's the "system".