What are the criteria and what types of characters tend to be classified as mary sues or gary stus. It seems like there are a wide range of (specifically female) characters that are labeled mary sues and not one of them are alike. Some are pure at heart and just good people. Some are anti heroes. I know someone said that the first ringer for a mary sue is a tragic backstory or circumstance. I disagree. Tragic backstories and circumstances provide the protagonist with motivation and drive. If their lives are just plain jane up until the story's events, then they really have no urgent goals. But that's just my opinion. But in your opinion, what are the criteria for a Mary Sue? What should people look out for in their characters to keep them from being labeled mary sues? And are there any traits or qualities that are never considered a mary sue trait?