The Law of Armed Conflict (LOAC) and Rules of Engagement (ROE) both govern how military forces may use force, but they operate at different levels of authority and with different purposes. LOAC is the floor — the minimum standard set by international law that cannot be waived. ROE is the operational framework layered on top, which can only restrict, never expand, what LOAC allows. What They Are LOAC — Law of Armed Conflict