A plea that certain conduct does not constitute a crime because it was committed in obedience to the orders of a superior (usually a superior officer in the armed forces). It could arise, for example, on the unjustified shooting of a rioter when the military are restoring order. UK law does not recognize the plea as a defence in itself. If an order is manifestly unlawful (for example, an order to commit genocide or crimes against humanity), a soldier's duty is to disobey it. If, however, an unlawful order is not manifestly so, the plea could be raised as establishing that the soldier did not have the necessary mens rea.
Subjects: International Law.