The castle doctrine refers to an exception to the duty to retreat before using deadly self-defense if a party is in their own home.
Under the doctrine of self-defense, a party who reasonably believes they are threatened with the immediate use of deadly force can legally respond with a proportional amount of force to deter that threat. The doctrine of self-defense is subject to various restrictions which differ from jurisdiction to jurisdiction.
One such restriction on self-defense is the rule to retreat. In jurisdictions that follow the rule to retreat, a party is not entitled to a defense of self-defense unless they first tried to mitigate the necessity of force by fleeing the situation, so long as retreating could be done safely. That said, in jurisdictions that follow the castle doctrine, this restriction has an exception for parties in their own home. A party in their own home does not have a duty to retreat and, therefore, is entitled to a defense of self-defense so long as the other requirements of the defense are met.
[Last updated in July of 2022 by the Wex Definitions Team]