This article assesses the impact of weapons, especially firearms, on three types of outcomes of threatening or hostile interactions: (1) whether a threatening situation escalates to an actual physical attack, (2) whether the attack is completed, i.e., results in an injury, and (3) whether the injury inflicted results in death. Data on violent incidents among strangers, taken from the 1979–1985 National Crime Surveys and the 1982 Supplementary Homicide Reports, were used to estimate bivariate probit equations with a correction for sample selection bias. Results indicate that deadly weapons, including firearms, appear to inhibit attack and, in the case of an attack, to reduce the probability of injury, whereas, once an injury occurs, they appear to increase the probability of death. The overall net effect of the availability of guns on the probability of the victim's death is very close to zero.