If your OC is a full-power alicorn, you are a bad writer and should feel bad. However, there are lots of other ways to make an OC too strong that seem harmless at first. Here is a list of early warning symptoms I came up with.

Your OC might be OP if:
-They are the best in Equestria at something, especially if it's something common (like an earth pony that's stronger than other earth ponies).
-They beat one of the mane 6 at a contest that both parties joined willingly.
-They teach Twilight Sparkle anything.
-They are proficient with a kind of magic you invented.
-The princesses and/or the core cast come to them looking for help (especially if it's because they can't handle a problem).
-They are the only pony who can _______.
-They are a changeling that can do anything other than change appearance.
-They are a made-up species.
-They are personal friends with every canon character, including royalty.
-They have a reliable way to cheat death.

None of these things would break a story by itself, but as these symptoms start to accumulate, the character gets progressively more boring. There are OCs out there that have done all of these things.

Being overpowered is a much bigger concern in a serious story than it is in a comedy. In humorous writing, a little overpoweredness can help make the situation silly.

Power only becomes a problem when you want to set up suspense or drama. Everyone knows that Princess Deathstroke can't lose, so there's no suspense. (If someone actually used that name for an OC, I apologize.)

4744380 I am a bad writer, and I feel bad.

4744426 There, there. At least you made it a long process to get there.

4744426 I just recently noticed that Clueless in Equestria has this at the end of the description:

Additional Tags: Not chosen one, no super powers

He's come a long way, hasn't he?

4744448 He is currently back to being a mostly normal earth pony. Despite any amount of power he might have, the world is happy to show him that you cannot superpower your way through most problems in life. In fact, the last time I can think of that he really cut loose a significant amount, it resulted in one of his closest friends dying terribly. Things do not always work out so well. True friendship comes not from super powers.

4744380 A decent list. My thoughts.

-They are the best in Equestria at something, especially if it's something common (like an earth pony that's stronger than other earth ponies).

I would agree with this. But you could work with it still. Would not recommend this still.

-They beat one of the mane 6 at a contest that both parties joined willingly.

Once. Not really. A couple of times. Eh, not so much either. All the time. Yes.

-They teach Twilight Sparkle anything.

Don't agree. Who said she can't be taught anything at all. Would you call a canon character OP if they teach her something? Still wouldn't count as OP even if they were just smarter than her.

-They are proficient with a kind of magic you invented.

Agreed.

-The princesses and/or the core cast come to them looking for help (especially if it's because they can't handle a problem).

This is not so much OP as falling into the Mary Sue category. But depending on the story, can be worked.

-They are the only pony who can _______.

Depends on what it is they can do. Sometimes it's OP, sometimes it's just stupid. But no point in the whole "only one who can" regardless.

-They are a changeling that can do anything other than change appearance.

I'd say only if it's something changelings aren't presented to be able to do. Don't understand why people do this though.

-They are a made-up species.

Eh, depends on what they can do and such. People make things up all the time. Nothing wrong with something new or different. Someone made up what ever is used already.

-They are personal friends with every canon character, including royalty.

Not OP, just Mary Sue realm.

-They have a reliable way to cheat death.

Yep. Fully agree.

4744390

Actually, that sounds like a good name for a villain.

Lets see, Diamond Dancer..

-They are the best in Equestria at something, especially if it's something common (like an earth pony that's stronger than other earth ponies).

She holds the world's record for highest flying filly. I guest that counts for something...

-They beat one of the mane 6 at a contest that both parties joined willingly.

Diamond once raced Rainbow Dash. Diamond lost by 4 minutes and 26 seconds. XD

-They teach Twilight Sparkle anything.

Hahahah. Diamond's not the smartest cookie in the box. She's never even Met Twilight

-They are proficient with a kind of magic you invented.

Diamond only has Pegasus Magic. Walking on clouds, flying with a special contrail,

-The princesses and/or the core cast come to them looking for help (especially if it's because they can't handle a problem).

Well...Diamond Works for Princess Luna as an errand girl. If the princess said "I need you to deliver this important document to Gryphonstone, would that count?"

-They are the only pony who can _______.

Guilty. Diamond is the only pony in the world that can survive a 5000 foot drop and walk away. Much to comic effect, of course.

-They are a changeling that can do anything other than change appearance.

Nope.

-They are a made-up species.

She's a crystal pony, so, it's canon

-They are personal friends with every canon character, including royalty.

Diamond has never met Twilight Sparkle. Diamond also hates Rainbow Dash. She thinks she's way to arrogant. Diamond absolutely loves Pinkie Pie and Fluttershy, but Applejack tends to get on her nerves, and Rarity helped craft her star piece into jewelry, but the prissy pony also gets on her nerves. She is wary of Princess Celestia, but absolutely adores Luna...that about covers it. So, no, I don't think so.

-They have a reliable way to cheat death.

Guilty. Yes, Diamond cheats death on a regular basis. Not because she wants to, her story around that is complicated.

Ehhh...not so bad.

4744493 Your point is well taken; I was mixing up overpowered and Mary Sue, though arguably, both are situations to avoid.

-They teach Twilight Sparkle anything.

Don't agree. Who said she can't be taught anything at all. Would you call a canon character OP if they teach her something? Still wouldn't count as OP even if they were just smarter than her.

I would defend this one by saying that Twilight is the most OP character in canon, and her encyclopedic knowledge is a major part of that. They frequently refer to her having read "every book." In the show she has moved to a teaching role instead of a learning role. (If a story was set in the past, that would be another matter entirely)

I think any of the things on the list can be mitigated with careful writing. These are just things that frequently show up in overpowered characters.

4744380 At the risk of sounding a little stupid, could you please define "magic I made up"?
I had one OC in development who was a Canterlot magic scholar and she specializes in fire and healing magic. This is something that's not canon, but the show's "magic" can usually equates to either telekinesis 97% of the time or any random power from time travel to making moustaches.
I mean, as long as I don't make a character an expert in something like space-time magic, it'd be alright?

4744590 By the way, it kind of already is a villain name...

4746504 That counts as magic you made up. As I said above, these things don't necessarily mean your character is overpowered, just that they might be. In your specific case, it would be easy for a fire and healing specialist to become really, really strong. Healing spells in particular can de-fang any threat if you are moderately proficient.

For balance purposes, consider Dungeons and Dragons or any of those rpgs. Fireball throwers and healers are generally separate classes because each ability is so strong by itself. For a more extreme example, consider Wolverine: he's one of the most powerful characters in X-men because of his limited healing powers (he can only heal himself).

Of course, how strong is too strong depends on your enemies, although being able to hold out against super-powerful enemies is also a kind of overpoweredness.

Take one of my OCs as an example of overpoweredness through made-up magic:
Star Burst is a unicorn that was raised by earth ponies...-skip lots of irrelevant backstory-...has a large magical reservoir and a strong affinity for telekinesis, to the exclusion of most other spells. Her upbringing has left her ignorant of the finer points of unicorn magic, but she had ample opportunity to practice her TK doing farm work.

So far so good, right? In exchange for her amped-up TK, I made her ignorant and inflexible. It seemed like a fair trade until I started considering her development. I thought, "What if she didn't have to move an object to use her TK? What if she could just push?" Now she could create beams of pure force, which had obvious offensive applications. Also, it made sense for someone of her potential to get trained eventually, and before long, I'm looking at a self-propelled magical cannon that can rival Twilight Sparkle. Where did I go wrong?

Even levitating a whole house is not as overpowered as knocking down buildings with a laser from your face, and that was what Star's force beam became when taken to its logical conclusion.

What I am trying to say is that any magic you invent would naturally improve during a story. The overpoweredness doesn't come from the concept, it comes from the culmination.

4746504

4744590 By the way, it kind of already is a villain name...

You're thinking of Lady Deathstrike. Totally different.

4746638 So not only should I balance out the power with flaws I got to make sure the magic doesn't improve to high levels? Okay. Makes sense. In gaming terms this is called "nerfing", by the way. The idea of giving my character, Fireheart, healing and fire, is from original concepts to when she was associated with phoenixes and that was back before FiM was a thing (but that's a story for another day ). Point is, I've matured as a writer since then and I'm still getting the hang of things, years later. Now of course, this Fireheart will only be loosely associated with phoenixes. She's not a hybrid or some pony equivalent of Spider-Man. She's been an important character in my stories in a meta since and I plan on bringing her (and some other characters) back as OCs and I want to get it just right.

4746647 No... I was referring to the DC villain Deathstroke. Remember Slade from Teen Titans? That was his alter ego name.

4746681 In my personal and untrained opinion, the way to get good suspense is to have your hero go into a dangerous situation with no obvious chance of winning. If the situation is similar to one that occurred earlier in the story, it's a test that they failed last time.

Flameheart sounds pretty cool, which means the only way for her to appear helpless is for her to be gifted, but surprisingly weak. (Or you could go the Superman route: He has unlimited power, but he's usually too stupid to remember that he has unlimited power.)

Fireheart sounds pretty cool

4746920 Thanks. Originally, she was a human witch, and, in translating her into an Equestrian persona, I made her a Canterlot magic scholar. A good majority of my old characters were witches or transformed dragons, so the challenge isn't translating them into the FiM setting as much as it is rounding them out and making them "balanced" (and changing these once darker characters to fit into a lighthearted setting) because when I wrote them so long ago, I made characters that I thought were cool, so this conversation really helps.
I'll make a note of this advice. It'll be a big help.

4744380 I have two of these symptoms for a character. Jirard is a unicorn who knows something nopony else does, he can hide himself (or turn invisible) by hiding in shadows, and he can also use shadow magic which is the other one. He's not more proficient than other ponies, at anything, but he does know some magic and that's about it. I just hope he's not OP.

4744380
My OC can play the bass trombone, is that too OP?

It's kind of funny, looking back at this thread. I threw out my opinion like it was fact, and a bunch of people who never met me are asking for my approval of their characters. All I really did was make a list of things I frequently saw in characters that I thought were OP. I have no official training, and only a little writing experience. I'm just an opinionated reader.

Since you ask though,

4857540 The only non-alicorn shown using shadow magic enslaved a large city and called himself "King" so that could easily be overpowered, depending on what Jirard can do with it. (Using shadow magic to chill drinks would obviously not be overpowered, but who would use it for that?)

4857559 Yes. Only gods play bass trombone.

4857647 Jirard can only use shadow magic to hide himself from danger. I think he may also be able to heal people with it but that's it.

4857647
*stamps foot*
God damnit son of a motherfu-

4857653 I was joking, but I suspect you were as well.

4857652 Stealth powers are nice and flexible, since they keep you alive, but don't really help you do anything else unless you are also clever. It's also easy to have a reason for them to fail at the most inconvenient time. Stealth is also great for tension, since there's always the implication that simply being discovered would mean total failure.

4857657
Haha, of course I was! I wouldn't ever actually react to something like like I did and be serious about it~

4857666 Yep, that's true. So you think he isn't too OP?

4857780 *shrug* Maybe? If he is OP, it would be from the healing and not from the stealth. Is the story written already, or still in the concept phase?

4858070 There is no story yet, he's just an OC. When it comes to healing, he can only heal moderately. He's not great or anything, that's left up to his Rival Brother (Yeah, I forgot to mention that.) who is a Light unicorn, he's not OP either, he's just full of himself and shiny and wears golden armor and yeah, stuff like that.

4858076 Sounds like you're going for a reversal of traditional color-cue tropes.

4858810 Indeed, they're both light magicians who can hide themselves. His brother can make himself so bright that everyone is blinded, while Jirard himself can become invisible by hiding in shadows. Of course, his brother's power negates his.

4859518

Of course, his brother's power negates his.

That would be the most important indication that Jirard is not OP. If his nemesis has a reliable bypass to his powers, he is as vulnerable as if he never had them in the first place.

4859635 Cool, so he won't be too ultimately powerful.

4744380

4744493

4746681
MAGIC and all of that (spell enchanted )
4857647

4858810
COLOR !
https://www.fimfiction.net/group/199126/meet-the-ocs/thread/473333/good-character-design#comment/7528175