AI dictionary for work
Ratio decidendi
The legal reason for the court’s decision.
What it means
Ratio decidendi is the legal rule or reasoning necessary for the court to decide the case. It is the part of a judgment most likely to matter as precedent.
Why it matters at work
When AI summarizes a case, ask it to separate the ratio from background facts, comments, and the final order, then verify the paragraph yourself.
Beginner mistake
Quoting any sentence that sounds useful without checking whether it was necessary to the decision.
Example prompt
Using only the judgment text below, identify the possible ratio decidendi and the paragraphs that support it. Mark uncertainty clearly.
Last updated 2026-06-16 · Reviewed for current AI tools