The Mary Sue trope is one of the most dreaded in fiction, sure to alienate readers. Mary Sue characters have ruined Star Wars (Rey) and Star Trek (Michael Burnham). What is a Mary Sue, you ask? The original “Mary Sue” was a parody of a character type that typically showed up in Star Trek fan fiction. Signs of a Mary Sue include:
- Everyone instantly loves her and trusts her, even though they have no reason to.
- She is better than everyone at everything. Training and experience are irrelevant because she’s just awesome.
- Everything she needs comes to her when she needs it.
- The team would be helpless without her.
- She has no flaws or weaknesses whatsoever.
In this writer’s question, I try to stop a writer from creating a Mary Sue.
Question:
I’m writing a fantasy, but my MC is from the contemporary world (who then travels to the fantasy world). …I was wondering how a relatively normal, modern girl would develop a fighting style … without just instantly being good at it for the sake of the plot. She’s also not combat trained, since I figured that would be a little too convenient. I want her to be a normal girl who has to grind her way through the fighting side of things, and who uses her resourcefulness to balance out her shortcomings when it comes to being untrained.
I had an idea that perhaps she has some sort of talent that she could adapt INTO a fighting style throughout the course of the story. Perhaps she’s trained in some form of fan dancing and gymnastics, as I like the idea of something “feminine” like dancing being incorporated into combat. However, in my research I haven’t been able to find a fan dancing technique that I felt could work. They seemed a little too slow. At the moment, I’m considering baton twirling. The fast movement of the batons seems to fit with how I see my MC wielding her two weapons. …
I guess I’m wondering if you’d buy the logical leap of my protagonist using her baton experience (or fan dancing, whichever I go with) to inspire her combat in the fantasy world.
Answer:
Don’t make her a Mary Sue, a female character who is instantly good at everything. That’s why everyone hated Rey in the Star Wars sequels. If she has no training in combat, she needs training, pure and simple. As for incorporating dance or gymnastics, I like that idea (not necessarily fan dancing). If she has baton training, she could make that work to her advantage, but again with training and practice.
Have her go through the training and make mistakes. Maybe early on she tries to use her dancing/gymnastics, and her teachers beat her easily. She goes through training in standard combat. As she masters that, she finds ways to incorporate her other skills. I would recommend reading about Arya in Game of Thrones. In the first book she is given a sword teacher from Braavos, a people known for their “dancing style” of swordsmanship.

Mary Sue vs. Strong Female Character
There is a difference between a strong female character and a Mary Sue. It’s fine to have a woman who is strong, tough, and/or exceptionally talented in some ways. Sarah Connor from Terminator 2 and Princess Leia I think are two great examples of that. Arya was a great character in Game of Thrones at first. But as the show went off the rails in the end, so did she.
I gave a hint above on how to avoid making her a Mary Sue. Have her go through training and struggle to master the fighting techniques she needs. Have her lose to her instructors and other students in practice. Give her a reason to persist no matter how hard it gets. Why does she want to master these weapons? The reason has to be compelling enough that she will not quit, even when everyone else thinks she should. As she masters her weapons and starts beating the other students, we’ll feel like she earned it.
If you want to know whether your character is a Mary Sue (or Gary Stu, as it may be), these links will help you identify her and transform her into a character people will root for.
What Is a Mary Sue Character? – The Moonlighting Writer
The Problem with Perfect Characters: Mary Sues, Gary Stus, and Other Abominations – TCK Publishing