Resources to do with character relationships

Does anyone know of a resource (website or book) that goes into detail about character relationships? As in, what makes for interesting friendship / rivalry / enmity between characters in a story. Things like shared history, a clash of personality or values, contrasting strengths and weaknesses in the characters, roles people can have in a group, etc.

(Searching for “character relationships” returns a lot about romantic relationships, which is not my main focus).

This article has a few ideas: trueherostudio.com/producer-blog … ationships

It’s a tricky thing to search for, but you may have more luck searching for novel-writing advice and going from there. I was able to find a few articles on friendship but most weren’t very helpful (this one had some interesting points.)

I think Joey has the right idea about searching for novel-writing advice. Stephen King is a master of creating memorable characters and relationships, so I’d recommend his book: On Writing: 10th Anniversary Edition: A Memoir of the Craft

A belated thank you for those ideas …

This was to help think through NPC relationships for this blog post:

intficpossibilities.blogspot.com … ships.html