Why is legal English so impenetrable?
For historical, practical and — less flatteringly — professional reasons, and the balance between them is genuinely debated.
Historical layering. English law developed across languages. After 1066, court proceedings used Law French, with Latin for records, alongside English. Lawyers hedged by using terms from more than one language together, which is the origin of the doublets still embedded in legal writing:
Free and clear, goods and chattels, null and void, last will and testament, breaking and entering, cease and desist.
Each pairs words of different linguistic origin meaning substantially the same thing.
Precision, genuinely. Some complexity is doing real work. Terms of art — consideration, estoppel, joint and several — have precise meanings established by case law, and replacing them with plain words loses accuracy. Long sentences with many qualifications frequently reflect an attempt to cover every case unambiguously.
Precedent. Wording tested in court and found to mean what was intended is safer than clearer wording that has never been litigated. This is a strong conservative pressure: a drafter who improves a clause takes on the risk that a court reads their version differently. Copying survives because it is defensible.
Less defensible reasons: complexity as a barrier to entry that sustains the need for lawyers, and drafting by accumulation — adding to a precedent without removing anything.
What the plain language movement has changed. The critique, notably from David Mellinkoff and campaigners such as the Plain English Campaign, holds that most legal writing is unnecessarily obscure and that obscurity harms the people bound by it.
Real progress has followed: UK consumer contracts must be in plain, intelligible language, with ambiguity construed against the drafter; the Woolf reforms replaced Latin court terminology; and plain-English drafting is now standard in legislation and much commercial work.
Studies have found that plain-language versions improve comprehension without losing legal effect — which undermines the precision defence for much routine drafting.