High Quality Content by WIKIPEDIA articles! In military or police operations, the rules of engagement (ROE) determine when, where, and how force shall be used. Such rules are both general and specific, and there have been large variations between cultures throughout history. The rules may be made public, as in a martial law or curfew situation, but are typically only fully known to the force that intends to use them. The ROE should comply with the generally accepted martial law. The most widespread and most accepted rules of engagement (ROE) exist within the North Atlantic Treaty Organization (NATO) and are generally designed as operational rules for commanders of battalion-level and larger forces and Commanding Officers of warships. In times of rising numbers of terrorist attacks and piracy, both defined as "outside of declared-war situations," the ROEs gain ever greater importance to the various forces opposing them.