I see that Mary Sues are coming around for discussion again (but hey! meta about what we write, not how we talk about it!), and since this is a subject about which I actually care I will quote here what I wrote in (holy crap!) 2003:
Whatever the technical definition of a Mary Sue, I feel that its use as a bludgeon to discourage the insertion of original characters into fanfic represents a real problem. I would like to see the question "Is this a Mary Sue?" replaced by a more useful question. Perhaps, "Is this a well-rounded, interesting character whose presence in the story contributes to the storyline and the canon universe?"
I don't deny that there are many crappy stories with OCs in them out there. But there are also a lot of crappy slash and het stories out there using only canon characters. There is in fact a lot of crap out there. Deal with it.
Good stories with OCs are not easy, precisely because the author can't take it for granted that the audience cares about the OCs. It's the author's job to make that happen, and the only way to learn to do that is to practice. The use of "Mary Sue" as a slap against all kinds of OCs discourages that process. I think that's a shame. Mileage may vary.
I was going to say something about my re-entry into fandom and writing OFCs, but I can't summon any coherence.
While finding this bit of commentary I happened across that thing I wrote about John Winchester and Romanness, and it occurred to me that the John=Roman and Sam&Dean=Greek equations might explain a good deal about the shift in the treatment of female characters on the show between seasons 1-2 and the later ones (at least if one thinks that in S2 Sam and Dean are still dealing with John's story). As I said there (and still maintain), patriarchy in Roman culture is at least in part about controlling children, while patriarchy in Greek culture is all about controlling women.
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