Forty-six states have enacted "stand your ground" laws as of September 2014, notes Wikipedia. These states include West Virginia, South Carolina, Oklahoma, Nevada, Mississippi, Michigan, Kansas, Indiana, Florida, Alaska and Alabama.
Stand-your-ground laws allow individuals to stand their ground rather than retreat if there are reasonable grounds to believe that such action can prevent bodily harm or death, explains FindLaw. The first such law was enacted by Florida in 2005. Not all states have enacted specific stand-your-ground laws; some jurisdictions rely on judicial reinterpretations of existing self-defense laws.
State self-defense laws fall into one of three categories: "stand your ground" (where permission to use deadly force in self-defense is not restricted to properties), "duty to retreat" and "castle doctrine," according to FindLaw. Duty-to-retreat laws require individuals to back away from threatening situations and only use force if there is no alternative. The use of force is not permitted if the individual under threat is safely ensconced in his home.
Castle-doctrine, or "defense of habitation," laws, on the other hand, restrict individuals to standing their ground within the limits of homes, yards and offices, FindLaw notes. Jurisdictions such as Ohio and Missouri even extend these laws to personal vehicles. States that have enacted this kind of law include California, Oregon and Washington.