A stand-your-ground law (sometimes called "line in the sand" or "no duty to retreat" law) provides that people may use deadly force when they reasonably believe it to be necessary to defend against deadly force, great bodily harm, kidnapping, rape, or (in some jurisdictions) robbery or some other serious crimes (right of self-defense). Under such a law, people have no duty to retreat before using deadly force in self-defense, so long as they are in a place where they are lawfully present. Stand-your-ground laws cannot be invoked by someone who is the initial aggressor or otherwise doing something illegal. The exact details vary by jurisdiction.