A red team is an independent group that challenges an organization to improve its effectiveness. The United States intelligence community (military and civilian) has red teams that explore alternative futures and write articles as if they were despotic world leaders. Little formal doctrine or publications about Red Teaming in the military exist.
In wargaming, the opposing force (or OPFOR) in a simulated military conflict may be referred to as a red cell (a very narrow form of Red Teaming) and may also engage in red team activity. The key theme is that the aggressor is composed of various threat actors, equipment and techniques that are at least partially unknown by the defenders. The red cell challenges the operations planning by playing the role of a thinking enemy. In United States war-gaming simulations, the U.S. force is always the Blue Team and the opposing force is always the Red Team.