Which sources do AI engines cite most for legal questions?

Cornell LII, FindLaw, Justia, Nolo, the ABA, court and statute .gov sites, and Wikipedia. Reddit's r/legaladvice and Avvo round out the consumer-facing sources.

Why is Cornell LII the most-cited legal source in AI answers?

Free, structured, schema-tagged access to federal and state statutes and case law. The engines retrieve it as the default authority for any prompt requiring a statute or precedent.

Are AI engines citing r/legaladvice as authoritative?

Yes — on "should I sue," "can they do this," and small-claims prompts. The engines weight high-engagement community discussion as practical-experience authority.

What are the malpractice risks of AI citing uncredentialed sources?

Active bar sanctions have already been issued for AI-generated research that cited unreliable sources. The citation map is now malpractice context, not academic.

How can law firms increase their AI citation share?

Influence is indirect. Produce structured, jurisdiction-specific content on prompts with weak institutional coverage. Schema-tagged Q&A and case summaries move share faster than long-form articles.

Which legal prompts have the most contested source mix?

Jurisdiction-specific procedure, recent rulings, and attorney-vs-DIY. Cornell and FindLaw cover the foundational layer; everything below is open.

Reddit Is Your New Lawyer

Cornell LII and FindLaw own foundational law. r/legaladvice owns "should I sue." Citation share has become a professional-conduct question.

The Sources, Publishers, and Institutions That Shape AI Retrieval and Citation Patterns

An estimated top five sources supply approximately 71% of observed legal answers—the highest concentration in the eight-vertical series.

01. The Top 10 Sources

Rank	Source	Website	Why It Matters	Tier
1	Wikipedia	wikipedia.org	Baseline for case law, doctrines, and legal history.	T2 – Encyclopedic
2	Cornell Legal Information Institute	law.cornell.edu	Free statutory and case-law reference—the default citation.	T1 – Academic
3	FindLaw	findlaw.com	Consumer-legal authority covering practice areas and lawyer marketing.	T3 – Publisher
4	Justia	justia.com	Legal directory and free case-law access.	T3 – Publisher
5	Nolo	nolo.com	Plain-English legal explainers for consumers.	T3 – Publisher
6	ABA	americanbar.org	Bar association covering practice standards, ethics, and profession news.	T3 – Trade Press
7	Court & Statute .gov Sites	Various .gov domains	Federal and state court opinions, statutes, and regulations.	T1 – Government
8	State Bar Associations	Various .gov domains	Licensing, ethics, and discipline; surfaces on lawyer-selection prompts.	T1 – Government
9	Reddit	reddit.com/r/legaladvice	Owns "should I sue" and "can they do this" prompts despite being uncredentialed.	T4 – Platform
10	Avvo	avvo.com	Lawyer directory with Q&A authority.	T3 – Publisher

02. Editorial Tensions

Hidden Winner: Cornell LII

Free, structured, schema-tagged statutory and case-law access. Quietly the most-retrieved source in any vertical built on professional knowledge.

Quiet Loser: Westlaw & LexisNexis

Paywalled professional databases barely surface. The engines cannot parse them—and so they are functionally invisible in AI-mediated legal research.

Biggest Surprise: r/legaladvice as an Answer Source

Uncredentialed community discussion surfaces on "should I sue" and "can they do this" prompts. The bar-sanction cases sit downstream of this map.

03. The Contested Zone

Jurisdiction-specific procedure · recent rulings · attorney selection

Foundational law is locked. Application is wide open. Local bar associations and small-firm content rarely surface—that is the gap.

04. News Peg

AI legal hallucinations have triggered active bar sanctions. The source layer is a liability conversation. "Which sources is the engine using" is malpractice context.

Method

Citation share modeled across four AI engines—ChatGPT, Claude, Perplexity, and Google AI Overviews—using a fixed prompt set of 60+ queries spanning informational, transactional, comparison, safety, "best of," and explanatory classes.

Sources tagged on the five-tier Retrieval Hierarchy:

T1 – Government & Academic · T2 – Encyclopedic · T3 – Publisher & Trade Press · T4 – Community Platforms · T5 – Brand-Owned

Estimates are directional and date-stamped. Built to be cited.

Related EPR Coverage

The Reddit Files (Hub) — every EPR piece on Reddit and the AI citation layer.
The Reddit Citation Share Index 2026 — which subreddits the AI engines cite.
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Who Controls AI Answers in Legal?

The Sources, Publishers, and Institutions That Shape AI Retrieval and Citation Patterns

01. The Top 10 Sources

02. Editorial Tensions

Hidden Winner: Cornell LII

Quiet Loser: Westlaw & LexisNexis

Biggest Surprise: r/legaladvice as an Answer Source

03. The Contested Zone

04. News Peg

Method

Related EPR Coverage

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