Self Defense has been an available affirmative defense to criminal cases since the dawn of society. Florida also has long acknowledged the fundamental right to use force in defense of self or others. The essential elements of self-defense have stayed about the same. A person may use deadly force when it is reasonably necessary to prevent imminent death or great bodily harm to the person or to another person. The procedure and burden of proof required to make a self-defense argument has changed.
In criminal cases alleging the use of force a defendant may seek immunity from prosecution. Today, this is called Stand Your Ground, but it has always been true that self-defense is a viable defense to any use of force case. A person seeking immunity has the burden to put forth evidence that the use of force alleged was reasonable against another's imminent use of unlawful force.