AI tell · grade contested
The rule of three: the AI tell our own data argues against
The rule of three, three parallel words or phrases stacked for rhythm, showed up in only 4 of the 12 models in our own logs, and even there, much of what a simple pattern-match catches turns out to be a literal enumeration, not a rhetorical flourish. Our social-sentiment research went further and found the entire premise, that a tricolon is evidence of AI authorship, disputed by the same communities that first proposed it. A device with a name from classical rhetoric, in use in advertising and speeches for as long as either has existed, cannot double as proof a sentence came from a model. underslop computes the pattern and reports it. It does not count against you.
What it is
A tricolon is three items given the same grammatical shape in a row: three adjectives, three short clauses, three nouns joined by 'and.' It is a rhythm device, not a formatting one, so it shows up mid-sentence rather than as a bulleted list. underslop's checklist also tracks a narrower, structural version under the same tell id: three bullet or numbered lines in a row, because the two habits often travel together in AI output.
How often it shows up
In our own logs (research/reports/ai-tells-empirical.json, entry emp-022) tricolon overuse appeared in 4 of 12 models, strongest in one that produced roughly two dozen instances in a single response, including 'help with practice, study habits, and preparation, but it can also be busywork, inequitable, and counterproductive.' That is a minority result, and the log entry itself notes that much of what a regex catches in ordinary writing is a real list, three ingredients, three loan types, not an ornament. Our social-sentiment review then surfaced direct pushback: a Wikipedia talk-page archive on AI writing describes the rule of three as good advice when used sparingly, and a working copywriter called it a legitimate decades-old device that models merely overdo. One weak empirical signal and one active refutation are why this tell sits in underslop's contested list rather than its scored one.
Why readers flag it
A single tricolon reads as ordinary craft; most readers do not notice it at all. What a careful reader does notice is density: two triads stacked in one sentence, or a paragraph where every list of examples happens to land on exactly three. That repetition is a real pattern worth naming. It is not the same claim as 'any three-item list is suspicious,' which is the version that does not hold up.
The fix
Do not cut a triad because it has three items. Cut it when the third item repeats what the first two already said, or when two triads land back to back and the rhythm starts to sound assembled rather than written. Keep a list of three exactly as long as all three items are doing distinct work.
Examples
It's a tool that can help with practice, study habits, and preparation, but it can also be busywork, inequitable, and counterproductive if overdone.
It can help with practice, study habits, and preparation. But it's also the kind of thing that turns into busywork, lands unevenly across students, and backfires when overdone.
Great question! The plan was fast, cheap, and effective. The team was sharp, focused, and driven. The results were clear, measurable, and repeatable.
The plan was fast, cheap, and effective. The team was sharp, focused, and driven. The results were clear, measurable, and repeatable.
Questions
What is the rule of three in writing?
It is the pattern of grouping ideas in threes, three adjectives, three short clauses, three examples, because three items read as complete in a way two feels short and four feels like a list. Writers and speechwriters have used it for centuries.
What is the AI rule of three?
It is the claim that language models overuse the rule of three specifically. Our own logs found it in a minority of models, 4 of 12, and our social research found the broader claim, that any tricolon signals AI authorship, actively disputed rather than confirmed.
Is the rule of three a sign of ChatGPT writing?
On its own, no. underslop computes it and reports it, but it never counts toward a score, because a rhetorical device this common in human writing cannot double as proof a sentence came from a model.
What is an example of a tricolon?
'Fast, cheap, and effective' is a tricolon: three matched terms in a row. It becomes a pattern worth noticing only when a paragraph leans on the same three-beat rhythm sentence after sentence.
How do I use a tricolon without it reading as AI-generated?
Use it once, and make sure the third item adds real information instead of restating the first two. The tell is not the tricolon itself; it is stacking two or three of them back to back until the rhythm becomes the point.
underslop marks this tell and the rest of the consensus set in any draft you paste, using the same open lint that scores it here. The free tier caps at 500 words a run, and your text is held for 0 seconds.