Homicide is when an individual sapient lifeform kills another, either by an act of volition or an inaction that causes death. This may result from negligence, recklessness or accidents, in cases referred to as manslaughter. When a homicide occurs with a defined intent to kill, it can be classified as murder or assassination. Forms of justifiable homicide depend on a civilization's application of law, and can include euthanasia, warfare killing, and state-ordered executions or assassinations.