Defense of others is a legal concept that allows a person to use reasonable force to protect another individual from imminent harm or unlawful aggression. This principle operates under the belief that individuals have a right to intervene on behalf of others when they witness an attack or threat, provided the response is proportional to the situation. It applies in both criminal law, where it can be used as a justification for actions taken to prevent harm, and in tort law, where it may affect liability in cases involving intentional torts.