Why AI Headcanons Read as AI — and Three Fixes
Three things give an AI-generated headcanon away, and none of them is vocabulary. One: the line is a personality adjective with a name attached instead of something the character does. Two: it ends with a sentence explaining what the headcanon means — the model narrating its own reading. Three: it never checked the character's gender, age or relationship to the other person in the prompt, so a male character tucks her hair behind her ear.
Each has a mechanical fix. All three take under a minute per line, and the order matters more than the edits.
💡 What You Will Learn
Three things give an AI-generated headcanon away, and none of them is vocabulary. One: the line is a personality adjective with a name attached instead of something the character does. Two: it ends wi
📜 Table of Contents
Why AI Headcanons Read as AI — and Three Fixes
It is not the vocabulary
The usual advice is to watch for words — delve, tapestry, testament. That is advice for essays. In a two-line headcanon there is no room for vocabulary to give anything away, and the tells that survive are structural.
People notice something is wrong before they can name it. What they are noticing is one of three shapes, and each one has a single fix.
One — the line is an adjective, not a behavior
A writer on r/WritingWithAI put the rule in six words: "adjectives aren't behavior. And behavior is what makes a character feel real on the page."
An adjective is the author's summary of a character. A behavior is the evidence a reader uses to reach that summary themselves. AI generators default to the summary, because that is what a summary of a character looks like in the training data.
Generated: Hermione is brave and loyal.
The line is not wrong. It is just not a headcanon — it is what you would write in a character sheet, and it could be pasted onto a dozen other protagonists without anyone noticing.
Rewritten: Hermione keeps a list of things she was right about, and adds to it.
Same claim about her. Now it is something she does, and it only fits her.
The fix: replace the adjective with a verb. One line, one action, no interpretation.
Two — it explains itself
This is the loudest tell and the easiest to miss, because the explanation usually reads as good writing.
Generated: She rereads old letters. This reflects her fear of being left behind.
The second sentence is the model showing its work. It has decided what the behavior means and told you, which takes the one job the reader wanted — noticing.
Rewritten: She rereads old letters. She has never written back.
The second sentence now adds a fact instead of an interpretation, and the fear is still there, arriving on its own.
The fix: delete the last clause if it starts with this, which, showing, revealing, highlighting or reflecting. Nine times out of ten the line improves and nothing is lost.
Three — it never checked who the character is
A complaint from r/MyHeroAcademia, about a generator asked to write for two male characters: "The AI doesn't seem to care what gender the characters are."
It is not a bug in one site. Unless gender, age and relationship are stated, a model fills them from the average of its training data — which means the average fanfic protagonist, and the average fanfic protagonist is a she.
Generated, for a male character: She tucks her hair behind her ear.
The fix: anchor the subject before generating, not after. Five fields, ten seconds:
- name
- gender
- age range (child / teen / adult / elder)
- role to the other character (lover, rival, sibling, stranger, subordinate)
- one contradiction to work against — a fear, a grudge, a habit they are not proud of
The last field does more work than the other four combined. A contradiction forces the model off the average, because there is no average answer to "what does this person do that undercuts their stated virtue."
Why the order matters
Fix them in this order, not in the order they bother you.
- Scan the subject first. If gender, age or relation is wrong, reroll — do not edit. Editing pronouns in an AI line produces agreement errors two sentences later, and those are worse than the original problem.
- Cut the tail. Delete the interpretive clause. This is free and always correct.
- Swap one adjective for an action. Only one per line. If you rewrite the whole thing you have written it yourself, which is a different job.
Reroll or edit?
The same thread that produced the gender complaint also produced its own answer: "Guessing OP rerolled until they got good ones."
That is the actual workflow in this community, and it should shape the advice. Rerolling is cheap — under a second on template sites, a few seconds on AI ones. Editing is expensive and introduces your own errors.
The rule that follows: three or more problems, reroll; one problem, edit that one thing. Teaching people to hand-edit every output is teaching a workflow nobody uses.
What still reads as AI after all three
Honest answer: sometimes the line survives all three fixes and still sounds generated, and the reason is rhythm. Models produce clauses of even length and put the important word at the end of a balanced phrase. Real headcanon writing is bumpier.
At that point the fix is not editorial, it is authorial — rewrite the sentence in your own voice, keeping the fact and dropping the cadence. That is the one step no generator can do for you.
Common questions
Does this apply to template-based generators? Partly. Templates are written by humans, so tells two and three mostly do not appear. Tell one does, because templates cannot know your character.
Will fixing these make it undetectable? No. It makes it good. Detection is not the standard to aim at — a line that passes a detector and reads flat is still a failed headcanon.
Is it worth doing for TTRPG prep? Usually not. At the table you want eight rough hooks in thirty seconds, and none of them will be read closely. Save the pass for anything that goes into a draft.
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