How to keep characters in character
"This feels OOC" is the comment every fanfic writer dreads, and the one hardest to act on, because it rarely comes with a reason attached. The reader felt a wrongness. They cannot always say where.
Here is the useful version of what they felt: it is almost never about what the character did. It is about why they did it. A character can do something startling and stay perfectly in character. A character can do something entirely ordinary and read as a stranger.
What "out of character" actually means
A character is a set of reasons, not a set of behaviours. Canon shows you a few dozen things someone did; what you are actually learning is the logic underneath — what they protect, what they refuse, what they will trade away and what they will not.
OOC is when the behaviour is reachable but the reason is not. Your character apologising is not OOC. Your character apologising *because they were afraid of being disliked*, when canon has shown they have never once cared about being disliked, is. Readers feel the second one even when they cannot name it.
Work from want and limit, not from traits
A list of adjectives produces an impression, not a person. "Sarcastic, loyal, secretly soft" tells you how a character comes across. It does not tell you what they do when the two of those collide, which is the only moment the writing gets hard.
Two things generate behaviour: what they want, and what stops them. Write those down for every character you borrow — one line each, in their own logic, not yours. "Wants to be needed. Will not ask for anything." From that pair you can write them into a situation canon never put them in and still get it right.
The dialogue test
Cover the speech tags and read the scene. If you cannot tell who is speaking from the lines alone, you have written one voice wearing two names. This is the fastest OOC check there is and it takes a minute.
Voice is rhythm and refusal, not catchphrases. How long are their sentences. Do they answer the question asked or the one behind it. What do they never say out loud. A character who deflects in canon and explains themselves in your fic has changed, whatever vocabulary you gave them.
Canon divergence is not OOC
Putting a character somewhere canon never put them is the entire point of fanfiction. A different situation produces different behaviour, and that is not a flaw — that is the experiment. The AU, the fix-it, the what-if all depend on it.
The line is whether the new behaviour follows from the old reasons. Same person, new pressure, therefore new action: in character. New pressure, and suddenly a different set of priorities with no event to explain the change: out of character. If you can name the thing that changed them, you are fine.
Keeping it straight across twenty chapters
Most OOC in long fic is not a misunderstanding of the character. It is drift. You were right in chapter two and by chapter nineteen you have been writing them for five months, and the version in your head has quietly moved.
In Bloomwright a character is a record — a role, what they want, what holds them back — written with you by the characters specialist and handed to the model on every reply, so chapter nineteen is written against the same person chapter two was. The bonds are stored as directions rather than pairs, which is the other half of voice: how they speak to *this* person, not in general.
Common questions
What does OOC mean in fanfiction?
Out of character — a character behaving in a way that does not follow from who canon established them to be. In practice readers use it for a mismatch of REASONS rather than actions: the character did something they plausibly could do, but for a motive the canon version has never shown.
Is it OOC if my character does something they never did in canon?
No. Canon shows a few dozen behaviours out of everything a person could do, so writing a new one is unavoidable and is the point of fanfiction. It is only OOC if the new behaviour comes from priorities the character does not have, with no event in your story to explain the change.
How do I write a character I find hard to pin down?
Find a scene where they refuse something, and one where they give something up. A refusal and a sacrifice tell you more than any amount of dialogue, because both reveal a ranking: what they put above what. Write that ranking down and you can generate behaviour instead of guessing it.