Lethal vs. Non-Lethal
One important consideration before we enter the bulk of this information is understanding the difference between lethal force (that which a reasonable person would assume to cause death or grave harm) and anything less (non-lethal force).
Much of the literature, instruction, and legal prosecution that addresses these issues concerns lethal force. The reason is simple: Homicide, no matter what the circumstances, is a big deal. Giving someone a broken jaw in a bar brawl is much less serious for everyone involved.
Legally, a line is sometimes drawn between lethal and non-lethal force, and sometimes not. However, we have chosen here to view situations involving force as generally homogenous, for two reasons: first, for simplicity, and second, because the basic precepts the law uses to establish justification for using force apply to using virtually all degrees of force. If a situation justifies kicking someone, generally speaking, you can use the same guidelines to decide whether you’re justified in shooting someone else. As a result, although many of the statements and examples given here will be focused on lethal force situations, you can feel free to apply their general principles across the board.