Fabricated cases, misquoted holdings, statutes made to say something they don’t — “hallucinations” aren’t random. They’re driven by specific, recognizable conditions of a legal task. This series names each cause, shows how it shows up in a brief, and explains what removes it before you file.
The conditions that spike a brief’s hallucination rate aren’t a single problem. They fall into three groups, and each has a different fix.
Demand-side causes come from the ask — the position you need, how much authority you demand, the shape of the template, and the voice you write the prompt in.
Supply-side causes come from the law and LLM training itself — where real authority is thin, where it has changed since the model was trained, and where the actual holding has been buried under mountains of media talking points, political rhetoric, and even non-lawyer mythology.
Process-side causes come from how the draft is generated — long chains of reasoning, long documents that build on themselves, and whether anything checks the citations before they’re used.
The wider the gap between the conclusion you need and the law that exists, the more the model invents to bridge it.
Ask for more supporting cases than actually exist and the model stops retrieving and starts generating.
A skeleton with a citation slot behind every heading tells the model an authority exists for each one — even when it doesn’t.
You don’t have to ask for a fake case. A prompt written to win nudges an agreeable model to invent the support your framing assumes.
Fabrication clusters exactly where real authority is scarce — a novel question, a small jurisdiction, an unreported corner.
A model is frozen at its cutoff. When a statute is amended or a case is overruled after it, the model keeps citing the world as it was.
When a legal topic becomes a public controversy, non-lawyer commentary can overwhelm the actual holdings the model learned.
The most mundane cause and the highest-leverage one: a cite is generated and used, with no step in between that confirms it exists.
Statute to regulation to case to exception — every joint in the chain is a place to substitute an invention for a real source.
An invention introduced early gets cited again and relied on later — one fabrication compounding into a structural one.
Verbatim reads a finished brief and reports, for every authority it cites, whether the cite is real and whether the quoted language actually appears at the pin cite — so a fabrication surfaces on your screen, not in a show-cause order. Bring a brief and we’ll walk you through the report.