4,000 lawyers, one AI drafting assistant, kept firmly out of the decision seat
Harvey AI × Allen & Overy · 2023–ongoing
What they did
Allen & Overy became the first BigLaw firm to deploy Harvey AI firm-wide in 2023, scoping it deliberately to high-effort, low-risk work — first drafts, document summaries, preliminary research — with every output subject to lawyer review, not autonomous filing.
What happened
Across 4,000+ lawyers in 43 jurisdictions, A&O reports an average 2–3 hours saved per lawyer per week, a 30% reduction in contract review time, and up to 7 hours saved on complex document analysis. The firm was named Europe's "Most Innovative Law Firm" in 2024, and Harvey has since expanded into PwC's legal services arm, reaching 4,000+ more professionals.
The so-what
The legal-AI deployments that have actually stuck share a pattern: assistant positioning, not autonomy — draft-and-summarize tasks where a licensed professional remains the last check, rather than tasks where the AI's output goes out the door unreviewed.