Hm, I don't think you can base a story on characters.
Ah! You're quite right. The Screen Actors' Guild does draw a clear distinction, as defined on this page
. The way SAG's credit system works, story is one thing and characters are another. This way, the creative processes are separated.
That's really good to know, thank you. This will definitely improve my legal-ese.
SF "Based on an Original Human Created by SF2" 3