Culpability, or being culpable, is a measure of the degree to which an agent, such as a person, can be held morally or legally responsible for action and inaction. Culpability marks the dividing line between moral evil, like murder, for which someone may be held legally responsible and an act of god, like earthquakes, for which no human can be held responsible. One formulation of the concept is as follows:

Culpability descends from the Latin concept of fault (culpa). The concept of culpability is intimately tied up with notions of agency, freedom, and free will. All are commonly held to be necessary, but not sufficient, conditions for culpability.