Ok, I know everyone has probably read enough things about Mary Sue to know how to spot them in a heart beat. Honestly, I don't think all Mary Sues are bad. Doesn't mean they're all good, just means that I will overlook the fact that something is Mary Sue if it is written well enough. Here are the most obvious signs of a Mary Sue. A few of these only apply to the HP universe.

Must be a female (not all female characters in FF are Mary Sues, but all Mary Sues are female)

She is caught in a love triangle between Harry and Draco. Maybe it's because I'm a straight guy, but why the hell does everyone think Draco is sexy? Same with Harry, Ron, Sirius, Severus, and all the other male characters (in cannon I think Draco was supposed to be ugly, and utterly stuck up).

Is a muggle born in love with Draco (That would be as likely as a Nazi being in love with a Jew, sorry to offend anyone but that's the truth).

If they are a cannon character, they are out of character.

The story revolves more along how they look.

The story is a romance (while this does not necessarily make any female character in a romance a Mary Sue, most female characters in romances are Mary Sue, and the guys are deballed).

Can do wandless magic (I have read a few where this is explained quite well). The major exception is crossovers.

Is an American exchange student (unless they're quoting Stephan Colbert (or another famous American patriot) at least once every chapter they aren't American enough for me to get over the fact that it is simply just too over used).

They are an OC related to any character (again this does not necessarily mean they are Mary Sue, they could be a pureblood and hence related to the Blacks, Weasleys, and even Voldemort)

Is written by a thirteen year old girl who either spends her whole life on the computer, or who has no idea how to write a good story

If any of you have seen a show on Nickelodeon called H2O those characters are a perfect example of a Mary Sue. (For fans of the show flame me all you want, I just watch tiny bits when reruns of Dirty Jobs are at commercials , so I don't even pretend to know anything beyond the ten or so minutes I have seen, and that ten or so minutes was a total waste of time)

Now few people dedicate anything to Mary's brother Gary. Maybe it is because eighty percent of all FF users are female. Maybe it's because no one cares. Maybe it's because he kicks so much ass that if we talk shit about him he will find us and kill us. Like a Mary Sue, a Gary Stu does not necessarily make a story bad. As a matter of fact, there are so many more Mary Sues than Gary Stus that it isn't as big of a problem. You know you have a Gary Stu if the character…

Is a guy (I mean a real man, the kind you see in old westerns, the guy who has both balls still attached, kicks more ass than Chuck Norris, and has muscles the size of Alaska).

Is in the Military (crossovers are again a major exception to the rule)

Is in a Special Forces unit (unless cannon this is almost guaranteed to make any character a Gary Stu).

Is American (and so masculine it isn't even funny).

Kicks ass.

There is no real romance to the story (as heartless as I am, even I have to say that a tiny bit of romance is required; however I would rather read something with no romance than something with tons of it). The exception is of course if the main character has no love interest in cannon

Makes GI Joe look unpatriotic (and weak).

Makes Captain America look weak, unpatriotic, and low ranking. (Colonel Stu, I had no idea you would be reading this).

Has a really high IQ (or if he doesn't, and he is in some sort of a squad, there is usually some smart chick to explain things, think Sam Carter from Stargate).

Kills an extremely powerful bad guy. (Easily)

Is written by a thirteen year old nerd who knows way too much about guns, plays too many FPSs , watches too many action movies, or doesn't know how to write a good story.

If it is in the HP universe…

He is more familiar with guns than a wand.

Knows Dumbledore is manipulative.

Kills Voldy and doesn't even break a sweat (There are some things in cannon called Horocruxes that would stop that from happening as easily as you want it to).

I will now wait for the reviews (good and bad), the flames (Strangely I have never received a flame on one of my stories), and wait for you to all say holly shit, that story I've been reading is a Gary Stu (or to think holly shit, that story I was gonna write where Harry gets shitloads of guns is a total Gary Stu).