Fabricated cases, misquoted holdings, statutes made to say something they don’t — these are legal citation “hallucinations”. They’re all caused by the stochastic nature of LLMs. That doesn’t mean there aren’t things that contribute to them. Quite the opposite — certain circumstances or recognizable conditions of a legal task can drastically increase hallucinations.
A brief doesn’t hallucinate at a constant rate. Some tasks are far more dangerous than others, and the dangerous ones are recognizable in advance — before you send the prompt, and certainly before you file.
Each article below names one of those conditions: what it is, why it drives the rate up, how it shows up in work you’d never flag as risky, and what actually removes it. The first is the largest by a wide margin — a brief that needs more support than the law actually holds — and it arrives in several disguises.
None of them can be solved by adding “only cite real cases” to the prompt.
The single largest driver: a brief that needs more support than the law actually holds — a losing position, a thin corner of practice, a citation count, or a template slot. Every one of them asks for authority that isn’t there.
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.
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.
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.