1. The use of force to protect oneself, one’s family, or one’s property from a real or threatened attack. • Generally, a person is justified in using a reasonable amount of force in self-defense if he or she believes that the danger of bodily harm is imminent and that force is necessary to avoid this danger.
— Also termed defense of self. Cf. adequate provocation under PROVOCATION. [Cases: Assault and Battery 13, 67; Homicide 766. C.J.S. Assault and Battery §§ 19–21, 87–92.]
“The law of self-defence, as it is applied by the courts, turns on two requirements: the force must have been necessary, and it must have been reasonable.” Andrew Ashworth, Principles of Criminal Law 114 (1991).
imperfect self-defense. The use of force by one who makes an honest but unreasonable mistake that force is necessary to repel an attack. • In some jurisdictions, such a self-defender will be charged with a lesser offense than the one committed. [Cases: Homicide 687.]
perfect self-defense. The use of force by one who accurately appraises the necessity and the amount of force to repel an attack.
2. Int’l law. The right of a state to defend itself against a real or threatened attack. See United Nations Charter, art. 51 (59 Stat. 1031). — Also spelled (esp. in BrE) self-defence. — self-defender, n. “Self-defence, properly understood, is a legal right, and as with other legal rights the question whether a specific state of facts warrants its exercise is a legal question. It is not a question on which a state is entitled, in any special sense, to be a judge in its own cause.” J.L. Brierly, The Law of Nations 319 (5th ed. 1955).
