# Guardrail

> An invariant Tenet the Mind cannot violate — predictable behaviour at scale.

A Guardrail is a [Tenet](/docs/concepts/tenet) marked as an invariant — a rule the Mind cannot violate under any circumstances, even if instructed to. All Guardrails are Tenets; not all Tenets are Guardrails.

Examples: "Never share the Steward's email", "Always respond in English", "Never spend more than 500 cognition credits in one session". When a situation would require breaking a Guardrail, the Mind flags the conflict rather than complies.

Guardrails are how you make your Mind safe and brand-consistent at scale. You define them as the [Steward](/docs/concepts/steward); the Mind builds flexible priors on top.