There are three things you want to ask yourself about your characters:
- Is my character developed and believable? Do they seem like a real person? Some people find “character worksheets” very helpful in developing their characters. It’s not hard to find character development worksheets online. Crawford Kilian provides a “character resume” which is not dissimilar. Elizabeth Moon has some detailed instructions on creating complex and realistic characters.
- What does my character *want*? Character arcs are determined by desire. I.E. what does your character want at the beginning of the story? Do they get it? Do they not get it? How does getting or not getting what they desire change them? A character who doesn’t want anything is flat, not to mention not believable.
- Speaking of flat, static, cardboard, round, and all sorts of other characters, James Patrick Kelly explains what the different kinds of characters are and how they function in a narrative here.