Circle of Duty

Circle of Duty is an arena style battlefield populated with successive waves of enemies. It is similar to Circle of Death and Circle of Slaughter. Unlike the other two circle arenas, it has its own area, whereas the other two arenas are located in small areas of a much larger map. Upon completing the final mission, you recieve a Gearbox-manufactured weapon of varying quality.

Missions

 * Circle of Duty: New Recruit
 * Circle of Duty: Cadet
 * Circle of Duty: Private
 * Circle of Duty: Corporal
 * Circle of Duty: Sergeant
 * Circle of Duty: Medal of Duty

Trivia

 * This series of arena missions has a few differences to the others.
 * It has its own map, instead of being a part of the Sunken Sea. The arena portion is much larger, much more tactical(cover and varied elevations are both plentiful), and has far more potential spawn points for enemies.
 * The combat is triggered not by merely entering the arena, but by stepping on a particular spot in the middle of it, which also happens to be devoid of cover.
 * The missions go up in ranks, instead of round numbers. There are also more of them.
 * The only enemies are Crimson Lance soldiers and Lancers.
 * The name of the arena is a reference to the 'Call of Duty' and 'Medal of Honor' games.
 * If you jump on the counter and crouch under the fence, you can hear the swirling sands from outside.
 * It's also possible to get a Gearbox weapon before the final mission.