In tort law, a defense that can be used against charges of trespass where a defendant interferes with a plaintiff's property in an emergency to protect an interest of his own. Private necessity does not serve as an absolute defense to liability for trespass. A defendant who commits trespass and invokes the defense of private necessity must still pay for any harm done to the property caused by his trespass, however, the defendant is not liable for nominal or punitive damages. Furthermore, as long as the emergency continues which caused the defendant to commit trespass on the plaintiff's land, the defendant is entitled to remain on the plaintiff's land and cannot be ejected as long as the emergency situation continues. Contrast with public necessity. See also necessity defense.