"A person being assaulted may defend himself if he has reasonable grounds for believing and does believe that bodily injury is about to be inflicted upon him. In doing so he may use all force which would appear to a reasonable person, in the same or similar circumstances, to be necessary to prevent the injury which appears to be imminent." Causey v. State, 2009 WY 111. A person is "justified in using deadly force to repel the danger only if he retreated as far as he safely could before using deadly force." Causey v. State, 2009 WY 111
Castle Laws are laws that address the use of force when defending one's self inside their home, or on their property. Some states expand this to vehicles, and the person's place of work. Castle Laws generally include: the places where this law applies, the requirements fro use of deadly force, if there is a duty to retreat, the amount of force that maybe used in defending one's self or others. These vary widely from state to state.