Plain-English AI definitions for legal professionals. For what bars actually require, see the Legal AI Compliance Register.

Chain-of-thought (CoT)

Using AI Last reviewed 2026-06-11

Definition A technique in which an AI model works through a problem step by step before giving its answer, either because the prompt requests it or because the model was trained to reason this way. It improves performance on multi-step problems.

In more depth

Asking a model to think step by step encourages it to decompose a problem—identify the rule, apply it to the facts, then conclude—which helps on logic, math, and analysis tasks. Newer reasoning-focused models generate extended chains of thought automatically before answering. The visible reasoning is itself model output rather than a guaranteed record of computation, so a plausible-looking chain of reasoning still requires checking.

Related terms

About the editor: MHSB Solutions, Research desk. MHSB Solutions is not a law firm. This glossary is educational information, not legal advice.

Educational information, not legal advice. AI terminology and tools change quickly; definitions reflect usage as of the last-updated date. For what bar associations and courts actually require of lawyers using AI, see legalaicompliance.help and consult a licensed attorney in your jurisdiction.