Alter-Ego Rule
Definition
Relating to defense of others, a common-law rule that an individual who comes to the aid of another “stands in the other person’s shoes” and has no more right to use force to defend the person than the person himself would have had to defend himself. The alter-ego rule has been abandoned in most jurisdictions in favor of the Model Penal Code rule that a person may use force in defense of another person if the circumstances as they appeared to the intervening person made it reasonably necessary for him to protect the other person.