Among the many character types to avoid when writing is the Mary Sue. This is an idealized character who stands in for the author as his idealized self.

This usually young and low-ranking character is flawless and always saves the day. Such a protagonist simply is unrealistic.

The Mary Sue character type arose from 1970s “Star Trek” fan fiction. The character was a female adolescent who was perfect at everything, was admired by the show’s Big Three of Kirk, Spock and McCoy, and who always resolved the story’s central problem. Though the original Mary Sue story satirized such unbelievable characters, it spawned several serious (albeit camp) fan fiction stories. Such characters usually marked a fan’s effort to live the fantasy of being in the “Star Trek” universe.

All great heroes – whether they be Odysseus or Captain Kirk, Luke Skywalker or Gilgamesh – display personal flaws and make mistakes. Though such characters represent cultural ideals of what we should strive to be, part of that lesson for readers involves the hero messing up and learning from it. Even comic book-styled heroes, such as the original Superman or the 1970s film versions of James Bond, made mistakes. If they hadn’t, the story’s climax would have come immediately after the central problem was introduced.

As Mary Sue can carry a negative connotation toward female protagonists, some literary critics and authors have taken to calling the male equivalent a Gary Stu or Larry Stu. Others use the gender-free Marty Stu, applicable to either sex. Variations of the term focus on specific skills that a young character excels at and so it dominates his/her personality – Einstein Sue for the genius, Jerk Sue for the short-tempered, Sympathetic Sue for the angst-ridden, and Mary Tzu for the tactically-inclined.