Have you ever heard of a MarySue? It's an OC - a character created by the author, who is always stronger, wiser, and more perfect than anyone else in the story. All the guys want to boink her, she captures the heart of the hero on sight and saves everyone from everything, without breaking a sweat. Invariably a thinly disguised fantasy persona of the author's - it's a way some authors have of writing themselves into a story and then going on to write fantasies of themselves with their favorite characters. Whether sexual fantasies, or otherwise. Major YUCK and horrendously boring.

I bring this up here, because an OC doesn't have to be a female to be a MS. Any time you sit down to create an original character and make them perfect, you're creating a MarySue. If you feel you need an OC, or just want an OC in your story, I'll give you the same advice I gave a friend once.

Create the flaws first. Decide who your character is. Ethnic background and looks, if those are important. Flaws. Faults. Failings. Perfect characters are boring. Your OC can be cowardly, have a heart condition so he can't run after the bad guys, be a lousy shot, be dishonest, snore loudly, whatever. But give him or her some flaws. BEFORE you decide what their virtues are.

Make them real.

Write a little backstory for your OC. Decide how they came to be standing there on that street corner when Methos walked by that night. It can be brief - a couple of paragraphs, a page or two. Decide if they loved their mother, if they hated history in school, if they refuse to eat Chinese and never pass up a Bela Lugosi re-run. Have they been in love, have they hated, what do they do for a living. How do they feel about Seinfeld, did they like the Beatles? Just enough information to make the character real in your head.

Trust me, this kind of detail comes through in your stories. It makes the characters internally consistent throughout the story and gives you a few details to drop in here and there to make them well-rounded in the reader's mind as well.

Okay, those ideas aside, what's the function of an OC?

(1) You love one character in a show, but can't see him slashed with anyone else in the show. No one else on-screen is his type. So, you make up someone who is his type. (Watch out for MarySue characteristics.)

(2) Exposition. You need someone from outside the fandom, a character who doesn't know anything about Sentinel abilities or about Voyager's struggle to return to the Alpha Quadrant. This outside person needs to have stuff explained to them, can interfere with the action in a ways the fandom characters, who know all about each other, can't.

(3) A bad guy/woman who exists only to be fought against and maybe killed off.

(4) Someone to interfere in the romance, strew the path of True Love with some thorns and obstacles that your heroes/heroines have to overcome.

There are variations and combinations and other good reasons to write an OC. On the other hand, you'll know you're on the wrong path, if your OC is in any way an idealized version of yourself, is perfect, or if everyone in your story is in awe of, lusting after, and/or jealous of your OC character.

I'm not even saying that writing a MarySue is forbidden. Nothing's particularly forbidden in writing. It's just that some stuff is more attractive to the readers than other stuff. And MarySue stuff is a particular <yuck> for most readers. You see this a lot more in m/f writing, where female authors make up some woman to stand in for themselves in their stories, but I've seen OC males characters written by men and women that are also obviously MarySue characters.

Heck, I've seen CANON characters distorted because the author wanted to use that character as a stand-in for themselves. When you're writing a love story for Methos and Duncan, try to remember that NEITHER of them is going to feel, think, or react the way you would to a situation. Even if you're a man. So, when you're writing these characters, don't write them feeling, thinking, or reacting the way you would. They are someone DIFFERENT than you - they have their own responses.

HOW DO I KNOW IT'S A MARYSUE?

Does the character have that "long, golden hair" you've always pretended you have, instead of the lank, dishwater locks you really possess?

Can you hurt this character? If someone says something mean to them, or if they get physically hurt, does it feel like the damage happened to you?

Do you dream of being just like this person? Do they have the audacious daring you've always fantasized about having? Are they the clever, witty conversationalist you've always dreamed of being?

Watch for things like these - they might indicate you don't have a really balanced perspective on this character and might indicate that it's a MarySue, instead of a fully fledged OC that will be of interest to the general reader.