Over 30,000 deaths each year result from gunshot wounds. Two decades of systematic research on weapons and personal violence indicate a pervasive influence of weapon type on the patterns and outcomes of violent encounters. The likelihood that an assault will result in death depends (among other things) on the lethality of the weapon. The evidence that weapon lethality affects the likelihood of death in suicide is somewhat weaker. Assailants' weapon choice depends on a number of factors, including the relative vulnerability of the intended victim and the general availability of firearms. National Crime Survey data indicate that guns are used only about 80,000 times each year in self-defense.