What is a guardrail?

Definition

Guardrails can act before, during, or after model generation. Examples include policy training, system instructions, input and output classifiers, tool permissions, rate limits, sandboxing, monitoring, human approval, and incident response.

Guardrails can change measured capability as well as safety. Looser restrictions may improve some benchmark scores, while stronger safeguards may prevent reward hacking, manipulation, extraction, or harmful actions at the cost of added refusals or friction.

ELI5

A guardrail is a rule or control that keeps an AI system inside safer boundaries. It does not make every mistake impossible, but it can stop known dangerous or unauthorized actions.

For example, a payment guardrail can block an agent from sending money to a prohibited recipient. The model may still request the transfer, but the trusted payment layer refuses to carry it out.

What forms can AI guardrails take?

They can include training, policies, classifiers, permissions, isolation, rate limits, monitoring, approval gates, audits, and response procedures.

Can guardrails affect benchmark scores?

Yes. Restrictions can prevent actions that raise a raw score, while looser settings can improve performance but increase safety or misuse risk.

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Definition card for guardrail: What is a guardrail?

A guardrail is a technical or procedural control that limits unsafe, disallowed, deceptive, or otherwise unwanted AI behavior.