Stopping power is a colloquial term use to describe the ability of a weapon to stop the actions of an individual through a penetrating ballistic injury. This term is not a euphemism for lethality; it refers only to a weapon's ability to incapacitate quickly, regardless of whether death ultimately results. Some theories of stopping power involve concepts such as "energy transfer" and "hydrostatic shock", although there is disagreement regarding the importance of these effects. Obviously, stopping power is related to the physical properties of the bullet and the effects it has on its target, but the issue is complicated and not easily studied. Critics contend that the importance of "one-shot stop" statistics is overstated, pointing out that most gun encounters do not involve a "shoot once and see how the target reacts" situation.