Archetypes vs. Mary Sues
Archetype: the original pattern or model of which all things of the same type are representations or copies (via merriam-webster dictionary)
Before I learned about archetypes in Language Arts class, I thought that Mary Sues were just bad characters, and that Mary Sue writers were unoriginal and amateurs. Now I know better. Luke Skywalker, Harry Potter, Tony Stark, Percy Jackson, King Arthur, Aladdin, Simba, Superman (he's definitely one) and Batman are all examples of the Hero archetype. (Notice how these are all men. I'll get to that later)
The Hero archetype is the main character, the story is centered around the Hero, and here are some characteristics of the Hero straight from a worksheet my teacher assigned:
Hero: A mythological or legendary figure often of divine descent who has great strength or ability.
*Occupation is war or dangerous adventure
*Nobel peers; gracious to followers and ruthless to enemies
*Resourceful and skillful in many crafts
*Man of action with a code of honor
*Accepts challenges
*Sometimes foolhardy, risking his life and the lives of others
Now do you see the connection? A lot of these are characteristics of Mary Sues.
So, about the clear sexism. The one major, major difference between the examples I've listed and Mary Sues is gender. Admit it, it makes you feel uncomfortable to have an all-powerful, seemingly-flawless, beautiful, likable, loving woman who rose up after a tragic backstory as a character. So, instead of mentally reprimanding yourself for misogyny, you accuse the author of wish-fulfillment, bad writing, and unoriginality. "Keep the girls realistic and make sure they don't make people feel uncomfortable, because suddenly someone did a gender-flip and made a girl powerful for once. That's not realistic." If you want realistic, read fanfiction for a nonfiction book. (If that can even exist) That's the whole point of fanfiction, is that it's the fiction of the fiction. And besides, having a powerful girl is completely realistic, it's just ten times harder with all of this sexism in the air.
Basically what I'm trying to say is that Mary Sues are just the female version of the Hero archetype. **
However...
That is no reason to make a bad character. In order for character development and an interesting plot to ensue, the character needs at least one prevalent flaw. They need a kryptonite , otherwise they will be boring. Bad characters are two-dimensional and monotonous, and they suck. No one wants to read something where the main character sucks. They can be all-powerful and practically perfect in every way, but they need a fatal flaw. And they need little habits that they don't notice. And they need to have a reason for blahblahblahinsertspecialabilityorcharactertraitinhere to have happened. They need a consistent personality.
Next time you find a bad character, don't just point and shout "Mary Sue!" Point and shout "bad character" because bad characters and Mary Sues are not the same thing.
** Yes, I know there's female heroes. But there's not a lot, and most of the time people don't like them.