The character arc is an interesting concept. It is the process whereby characters in fiction undergo change and end of the story as different people than those at the start of the story. This change, explains Victoria Lynn Schmidt, is something that happens as your characters respond to the situations in which they are placed, to the problems they have to overcome, and the interactions they experience with other characters.
These responses are not predictable, but they are driven by character traits in each individual character. The fiction writer’s job is to create characters with traits that cohere to make them believable and interesting people. And the good news in Schmidt’s book is that there are role models you can adapt in order to invent characters who will meet your needs.
Her book discusses a range of archetypal characters who can be your role models and shows how you can draw on Jungian psychology to develop them into fully rounded and interesting characters.