Nancy Kress does a fine job here at Brian Klems’ blog, “The Writer’s Dig”, in explaining the four different types of characters and character motivations there are in fiction. Deciding if your character is static or changing, or if the motivations do, will go a long way toward mapping/outlining your story and its plot.
Read the entire article by clicking the link, and enjoy this excerpt on how understanding the nature of your characters is a step toward understanding the nature of your story.
Some of your characters will change during the course of your story—let’s call them changers. Others—stayers—will not change significantly in personality or outlook, but their motivations may nonetheless change as the story progresses from situation to situation. Both changers and stayers can have progressive motivations….
When you know the key motivation(s) behind your character and plot, you can write scenes that not only make sense to you and your readers, but also add depth to your story. Because character and plot are intertwined, we’ll refer to the above four as character/plot patterns. Let’s further explore each one.