Fiona recently put up a review for Spoils of War, and the subject of the Mary Sue came up. Let me start off by saying this isn't a response to her review, let alone a criticism of it. But I've discussed Mary Sues with my readers as of late (by IM and in my comments section) and I thought it was an opportunity to raise the topic.
The Mary Sue is, for many writers, a bogeyman. The possibility that a character might get the label slapped on them is a constant fear, paralyzing. It can be one of the harshest criticisms a work can get, because of everything it suggests about the story (and often the title character).
What is a 'Mary Sue'? In brief, it's a term that came up starting with old Star Trek fanfiction. The original, nominal Mary Sue was created as a parody by an author wishing to point out flaws with many fanfiction works of the time. Since then the term has caught on, and more troubling, it's mutated somewhat. The end result is that 'Mary Sue' can get applied more often than is fair, and it's increasingly hard to define.
The Mary Sue is the character who's a thinly veiled replica of the author, inserted into the canon universe.
The Mary Sue is the character who, from the moment they step on the scene, turns the protagonists into side-characters.
The Mary Sue is the character who has the entire setting of the story revolve around her.
The Mary Sue is the character who, when she interacts with other characters, causes them to act uncharacteristically.
The Mary Sue is the character who gains new powers as the plot demands, because she's just not supposed to lose.
The Mary Sue is the character who strains credulity simply by her existence. She's a half-dragon, half-demon, half-elf. She's the long-lost, never before mentioned daughter of Gandalf, the -real- girl who lived (not that jerk Harry Potter).
She can be any of the above or only some, or she can be none of the above and still strike a chord that makes a reader apply the label.
And let's be careful to note that a Mary Sue isn't necessarily limited to fanfiction. People have said that major characters in popular literature have been Mary Sues. Harry Potter as the chosen one, who everyone's focus revolves around, who everyone loves or hates, who has innumerable talents and hidden traits and qualities. Anne of Green Gables becomes so charming and wonderful that everyone simply bends over backwards or falls in love with her in short order. Anita Blake is a necromancer, vampire servant, member of a triumvirate, black belt, detective, vampire executioner, has vampire powers, and has the power to call the lycanthropes that are wolves, black tigers, white tigers, jaguars, blue tigers, red tigers, gold tigers and lions.
All that said, I think the term is applied too broadly. I have further thoughts but don't want to ramble too much. I'll let others interject and share first.
Thoughts? Do you give consideration to the label, as a reader or writer?