License to kill is the official sanction by a government or government agency to a particular operative or employee to initiate the use of lethal force in the delivery of their objectives, well known as a literary device used in espionage fiction. The initiation of lethal force is in comparison to the use of lethal force in self-defense or the protection of life. The legitimacy of deadly force usage from country to country is generally controlled by statute law, particular and direct executive orders, the common law, or rules of engagement.