Glossary

One-bite rule

An older legal rule under which an owner is liable for a bite only if the owner knew the dog was dangerous, so in practice the first bite was often free.

Also called: one bite rule, first bite free, one-bite law, scienter, knowledge of vicious propensity

The one-bite rule is a traditional principle of common law. Under it, an owner is responsible for injuries only if the owner knew, or should have known, that the dog had a tendency to bite or act dangerously. In the past a first bite could go uncompensated unless there was earlier warning, which is why it was called the first-bite-free rule.

The name is misleading. Courts did not literally count bites, and a growl, a lunge or a complaint from a neighbour could be enough proof that the owner knew. Many states have since replaced or supplemented the rule with a strict liability for dog bites statute that makes the owner responsible regardless of earlier behaviour, and a few still follow the older rule.

The law differs by state, so the rule is not a safe assumption anywhere. If a bite happens, an owner needs to know local law and talk to a lawyer.

Last reviewed November 8, 2026

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Related terms

Strict liability for dog bites A legal rule that makes a dog's owner responsible for a bite injury regardless of whether the owner knew the dog was dangerous. Dangerous dog law A law that lets authorities declare a dog dangerous after an attack or threat and set conditions for its owner, such as an enclosure, muzzle or insurance. Leash law A local or state rule that requires a dog to be on a leash or under control in public, with set exceptions such as designated off-leash areas. Breed-specific legislation A law that bans or restricts dogs by breed or appearance, such as pit bull type dogs, rather than by what an individual dog has done.