Mary Sues are original female characters that are poorly masked portrayals of the author. They tend to fall into two categories: The super-amazing Mary Sue with mad talent/skills/powers whom all the characters love and worship, or the tortured depressed Mary Sue whom all the characters must save. In either case, Mary Sues are always drop-dead gorgeous and perfect. In slash fics, Mary Sues typically play the role of love doctor or matchmaker. In AFI fics, perhaps a more suitable term for a Mary Sue would be Raven Deathwinter or something equally ridiculous.
A story involving the regular cast with a new character who's better at everything than anyone in the show. This new character usually looks and sounds a lot like the author of the fic. The form is generally frowned upon.
Perfect female character - pretty, strong, clever… etc. If used incorrectly, can be intensely annoying. May also have a "mysterious" past, be a relative(long lost or otherwise)/new love interest/person who gets other people together or a variation thereof. Generally the story revolves around this individual, not around the more canon characters.
a story with an original female character who's perfect, does it all, saves the day, and is usually martyred; seen as amateur writing
A story where the author has blatantly written herself in as a romantic foil for one (or more) of the characters. A good Mary Sue explanation page is: Self-Insertion and Mary-Sue-ism.
a character introduced into an already existing Trek universe who serves as a wish fulfillment for--usually--the teenaged writer of the story
a character that, essentially, is nothing more than the author's representation of him/her self in the story world
a character who is actually the author
a character who's practically perfect in every way, and is often a self-insert of the author
a character written in so that
a cipher for the author, and is annoying because she is two-dimensional, perfect in every way (even her flaws are designed for maximum angst potential until she manages to overcome them), and completely unnecessary in an established fictional world
a fan characters who is created perfect, or at least near perfection
a fanfic character who is basically too good to be true
an old fanfic writer's term for a character (female, since the majority of fanfic writers are female) who's an alter-ego for the author
an original character (original to the fanfic author) and not a character in the canon
an utterly perfect character
a self insert character who is usually excessively beautiful, talented, intelligent and generally special, while lacking any actual characterization or depth
a story featuring a non-canonical cast member who bears an eery resemblance to the fanfic author herself
An original character who is basically just the author inserting a perfect version of him/herself into the story.
general] An original fanfic character, distinguished by her obnoxious perfection and her intimate (or *ahem* intimate) familiarity with canon characters. She is typically an idealized version of the author. Here in Miz-land, she is often called "Marie-Suzette" or "Marie-Suzanne" out of a general habit of Frenchifying words. The Mary Sue Society
a character, of either sex, who is too good to be true. Traditionally a creation of the fan fiction writer, and traditionally annoying or laughable. Mary Sues can frequently be identified by their stunning good looks: violet eyes, long silky hair, curly auburn hair; and their deeds: saving the ship and dying in the process, bringing the romantic characters together at the risk of their own life or happiness.
an original character who resembles a perfect version of you--or of anybody. The easiest way to annoy people and keep your story unread. Some people have extreme prejudice against original characters in fic (not me), but I suggest that if you write them, to write them with flaws. And also to do it very, very well.
A character who is clearly the author's alter ego and therefore incredibly perfect; incredibly beautiful--often with unusually colored eyes/hair; incredibly talented--often gifted musically and magically; has a tragic past; and is either related to or beloved by one or more of the show's main characters. Mary Sue may die in the arms of a series character, having given her all. Occasionally appears as a male, but because it's less common there is no commonly accepted name for the male: some references include Harry Sue, Barry Sue, or Marty Stu. In THE SENTINEL fandom, it's Blairy Sue, since Blair is often reduced to being a Mary Sue. Mary Sue as a term originated in fandom for the original STAR TREK series, when Paula Smith wrote a humorous piece about the incredibly perfect Lieutenant Mary Sue saving the Enterprise.
Mary Sue (sometimes shortened simply to Sue) is a pejorative term for a fictional character who is portrayed in an overly idealized way and lacks noteworthy flaws, or has unreasonably romanticized flaws. Characters labeled Mary Sues, as well as the stories they appear in, are generally seen as wish-fulfillment fantasies of the author.