Generative AI in legal practice: real uses, limits and best practices 2026

The real state of AI in Spanish law firms (2026)

Three years after the mass launch of LLMs (large language models), Spain's legal sector has moved from curiosity to systematic ( but uneven ) use. The use of AI tools among lawyers is growing, but not everyone uses them with verified citations from official legal sources.

That is the main risk: using generic generative AI (ChatGPT, Gemini) for legal research produces factual hallucinations ( invented articles, non-existent rulings ) that can lead to disciplinary liability.

AI uses with clear ROI

1. Drafting pleadings

AI is very effective for:

• Generating the skeleton of a brief (facts, legal grounds, prayer for relief) from case facts.
• Adapting the tone to the court type.
• Reviewing internal consistency of long documents.

What AI cannot do well: decide litigation strategy, assess witness credibility, predict a specific judge's approach.

2. Contract review

AI excels at:

• Identifying unfair terms in B2C contracts.
• Comparing a version against an industry standard.
• Summarising an 80-page contract into a key points table.

3. Legal research with RAG

AI systems with Retrieval-Augmented Generation (RAG) search verified legal corpora (BOE, CENDOJ, TC) and return answers with real citations. This reduces the risk of hallucinations when the corpus is well indexed, although it does not remove it: every citation must still be checked against the source.

Try Lexiel with RAG on official sources →