So You Want To Have A Powerful Or Talented Character Who Probably Won't Be Perceived As A Mary Sue?

Start by describing what makes your character tick, not what makes xir special.

When you begin your character profile/pitch, leave out your character's appearances, superpowers, and canon connections as long as you possibly can. Instead, start off with and emphasize your character's personality, ambitions, dreams, ideals, career, and vulnerabilities. Basically, all the things that drive and motivate your character. In short, if you took away all of your character's toys and goodies, who would xe be?

If you have a well-developed character, you should be able to describe xir without mentioning xir powers, abilities, or canon connections quite easily. Here's an example based on one of my own OCs (who is the daughter of two canon characters) - she's an intelligent, but socially-awkward young woman who works for her father's company as an accountant. Her current pet project and hobby is a tabletop RPG she's developing, which most people would probably find frustratingly fussy about details.

It also helps to write practical descriptions that relate your character to the world xe lives in, rather than the laundry list descriptions that are so very common these days. For more on doing this, see Common, Yet Terrible Character Descriptors - And How To Fix Them (And Write Better Descriptions In General).

Remove irrelevant specialness.

I've seen way too many "not-Sues" who have special/unique features for pretty much no other reason than the author found it appealing and decided to toss it in there. Something that's common in far too many characters I've seen are strangely-colored eyes or the presence of cat ears and a tail that have pretty much no relevance to anything. At least one OC superhero I've seen had cat ears and a tail, the reason given that her abusive father experimented on her as a teenager. The character must have cat powers, right? Nope. Her powers have absolutely nothing to do with cats, and the story of how she acquired her catliness has absolutely nothing to do with anything at all.

Compare with, for example, the Marvel-verse - if I see a character with an unusual appearance, I can usually trust that there's a character-defining story attached to it somehow - EG, Doc Samson received his green hair in the incident that gave him the powers that changed the course of his life. Storm has white hair because she is a mutant, a fact which has essentially defined her life since a young teen.

Give your character's talents, skills, or powers a cost.

The cost can be anything - it can be something your character has to give up or pay upfront (whether willingly or not), undesirable consequences, unpleasant responsibilities, a lot of time and effort put into honing the power or talent, or any combination thereof. It doesn't necessarily have to be huge or dire; just reasonably proportionate. Here are a few examples:

• Christopher Nolan's Bruce Wayne spends years learning martial arts, and has to put time and effort into building his bat-equipment. He doesn't simply go from Bruce Wayne, playboy to Batman, masked vigilante overnight.
• In My Little Pony: Friendship Is Magic, Twilight Sparkle isn't immediately able to fly very well after becoming an alicorn (a winged unicorn), but must practice at it. There are a lot of pratfalls along the way. Furthermore, becoming an alicorn was part of her promotion to a position that entails a lot of responsibility.
• In the same series, Rarity is an excellent fashion designer and tailor, but it's often shown that her job can be difficult and stressful.
• Buffy Summers may have superhuman strength and reflexes, but she still needs to train to keep up with the vampires and demons. Also, both training and slaying frequently take up time she'd rather be spending doing something more fun - eg, dating or socializing with friends.
• In Captain America: The First Avenger, Steve Rogers was only able to become Captain America after doggedly applying at every recruitment station he could find, and then facing bootcamp while still being small, skinny, and sickly.
• Elsa in Frozen has ice powers strong enough to make a castle from... but at the same time are uncontrollable and dangerous enough to force her to distance herself from her family and kingdom.

And make sure that you show it. Let people see your character have to turn down fun things in the name of responsibility, or get stressed out over deadlines, or struggle to learn a skill or master a power, and so on.

Let your character earn respect.

In far too many cases, characters just start out as members of the main characters' clique and/or the best friend/lover of whichever character the writer/player likes best. Don't do this. Instead, let your character start out as an acquaintance or stranger, someone the main characters do not know well. The players/readers will (if your character is written well) be able to bond with the new character as the other characters do - which means that by the time they are friends, the players/readers will genuinely care about your character.

Respect/love/friendship does not have to be earned via badassery or sheer strength/power/skill.

No, not saying your character should be a useless lump. But many people try to present or use their character's powers/skills as essentially the sole or main reason their character should bond with or be respected by other characters.

Powers and skills could explain why the characters might interact professionally - but they do not alone explain why two characters would become best friends or lovers. For that, your characters need to have compatible personalities, proper bonding experiences, and generally have done a lot of things together that don't have anything to do with being superheroes or whatever it is they are.

In one roleplay, a powered character I had became friends with a few canon characters due to circumstances that had nothing to do with his superpowers at all - some of the characters had been turned into young children, and he babysat and played with them until the effect could be reversed. Next thing you know, said character was getting invited to parties.

Finally, a lot of people seem to think their characters can earn the respect of other characters or become their best friends by insulting them. This is completely backward. In reality, you earn the right to insult someone by becoming best friends. And by that point, you understand that there are some lines you do not cross and that you don't start jabbing your best friend in xir vulnerable spots.

On the subject of creating a believable relationship between two characters, check out Tips to Write & Roleplay Believable Successful Long-Term Relationships. And if you ever intend or aspire for your character to be respected as a leader, check out On Writing & Roleplaying Characters Who Are Good Leader Material.

In the story, show what makes your character average.

Even if your character is some kind of superpowered genius from another dimension, take some time to figure out and show what makes your character not so different from any average person you might meet. This can include things like awkward character flaws, virtually useless hobbies, finding xirself in an awkward or embarrassing position because xe's clueless about what's being discussed or doesn't really know what's going on, or connecting to other people not as a Super Special Someone, but simply as an aquaintance or friend.

Don't make your character a vacuum person.

"Vacuum people" is a term I use to refer to characters who have essentially no social or familial connections at all, aside from the obligatory abusive/dead/disappeared parent/parental figure/s, and possibly canon characters they're supposed to know. In essence, these characters live in a social vacuum. To prevent vacuum people, next time you create a character, try to come up with the names and basic personalities of at least three of the following:

• Someone your character knows from a place xe shops or gets food.
• Someone your character regularly talks to at work/school.
• A non-immediate relative your character (eg, cousin, grandparent) that your character could contact if xe wanted.
• A former lover/love interest who is not dead or an enemy of some kind.
• Someone your character knew since/during childhood who is still alive today that your character still has positive feelings about.
• Someone your character talks to over the Internet.
• Someone xe knows from a public venue/space (eg, library, swimming pool, park).
• A service person your character hires.
• A neighbor your character talks to.

Note that your character should stay in contact with at least some of these people after meeting the canon characters. In practice, this can take the form of mentioning a joke their friend at the coffee shop told them, or asking somebody what sort of advice they should give xir online friend.

Obviously not all of these will apply - eg, no Internet acquaintances if there is no Internet in the setting - but there's no reason you can't work out, at a minimum, three of these items for any given setting. Also, these characters should all have different opinions about your character - some positive, some negative. Don't make other peoples' views of your character entirely polarized - IE, they either love or hate xir. Mix it up a little - give people (even the same people) reasons to feel both positively and negatively toward your character. Make some characters who, while they know your character to some degree, really have no strong opinion on xir either way.

Give your OC/fan character xir own place to live (and a job).

Living with canon characters is a pretty big red flag of Mary Sue-dom. For the vast majority of fan characters I see, there's no reason in the world why their stories couldn't reworked slightly so they have their own place to stay. Seriously, get your character xir own digs. There are bajillions of reasons for your characters to have contact with the canon characters that don't include actually living with them. Here are a few suggestions:

• Your character was hired as a consultant.
• Your character is a regular employee of another character's.
• Your character was commissioned or contracted to do a job. (EG, auditing, home repair or remodeling, server migration, tailoring, catering...)
• Your character works at a venue one or more of the characters frequent.
• Your character is delivering (or is) a plot hook.

(If a normal dayjob is good enough for Spider-Man, Superman, and Buffy Summers, it's good enough for your character.)

At all costs, avoid the "my character had nowhere else to go so they let xir stay with them" route. (Mind you, if you're in a roleplay and a player character is willing to let yours stay, that's fine, because you gave the other players the choice of whether or not to let your character live with them.)