Rules of engagement

They provide authorization for and/or limits on, among other things, the use of force and the employment of certain specific capabilities. In some nations, articulated ROE have the status of guidance to military forces, while in other nations, ROE constitute lawful command. Rules of engagement do not normally dictate how a result is to be achieved, but will indicate what measures may be unacceptable.

While ROE is used in both domestic and international operations by some militaries, ROE is not used for domestic operations in the United States. Instead, the use of force by the U.S. military in such situations is governed by Rules for the Use of Force (RUF).

An abbreviated description of the rules of engagement may be issued to all personnel. Commonly referred to as a "ROE card", this document provides the soldier with a summary of the ROE regulating the use of force for a particular mission.

Legal aspects

Since it constitutes “an operational modality of the use of armed force permitted under international law and not prohibited by domestic law”, no rules of engagement may render lawful conduct that is otherwise unlawful (e.g., firing upon an ambulance) under international humanitarian law. Rules of engagement “may instead authorize the use of force made necessary by an act of self-defence of the State, even where, in the specific case, the military personnel participating in the mission are not themselves the object of an offensive action. The same considerations apply where an intervention takes place in support of a State engaged in a civil war, provided that such intervention is lawful".