I’m thinking of developing a system for playing RPGs by yourself. There are a number of challenges to this. Mainly, how do you generate an interesting story without resorting to a load of random tables. My thought is to use the classic story structure to make this engine work. The player would roll on a table of the classic motivations for each scene. That would tell them if they were playing the Protagonist or the Antagonist in this scene. Other elements, possibly a deck of cards, could be used to flesh out what the type of challenge is.
Another element is that RPGs are inherently social. They are stories. If a story is not shared, then it feels empty. So I think there should be a healthy dose of structure as to how to record the game. Posting the story on a forum or a blog would suddenly make the game a shared story again.
The important thing that I want to shoot for is to make this system independent. There are a few solo RPGs out there already but they depend on custom systems to play. I’d prefer one that makes any RPG playable by one person.