Opposing Force

An opposing force (abbreviated OPFOR, used in the United States and Australia) or enemy force (used in Canada) is a military unit tasked with representing an enemy, usually for training purposes in war game scenarios. The related concept of aggressor squadron is used by some air forces.

At a basic level, a unit might serve as an opposing force for a single scenario, differing from its 'opponents' only in the objectives it is given. However, major armies commonly maintain specialized groups trained to accurately emulate real-life enemies, to provide a more realistic experience for their training opponents. (To avoid the diplomatic ramifications of naming a real nation as a likely enemy, training scenarios often use fictionalized versions with different names but similar military characteristics to the expected real-world foes.)

Opposing forces can also coincide with red teaming activities. Once the Analytic Red Team develops adversary tactics, techniques, and procedures (TTPs) it will be the opposing force that makes use of those TTPs in wargames and exercises.

Some dedicated opposing forces may fight using the likely enemy's doctrine, weapons, and equipment. They may wear uniforms which resemble the likely enemy's, or one dissimilar to "friendly forces". Their vehicles may either be those operated by the likely enemy's, or may be modified to look like those. All these measures help to enhance training realism and provide useful lessons on how to fight this particular enemy.

Blank ammunition, smoke grenades, and artillery simulators are often used by both sides in the exercise to provide the fog of war caused by the noise and smoke of battle.

In addition, a simulation system such as the Multiple Integrated Laser Engagement System (MILES) may be used. This system is attached to various weapons, and are zeroed to the sights of the weapon. When a blank round is fired, the system sends out a laser beam, which score "kills" or "injuries" on any soldier or vehicle in what would be the path of the weapon's projectile. These laser beams are detected by receivers on harnesses worn by the soldiers, or on the vehicle itself.

Alternatively, paintball weapons which look like real weapons, or simulation rounds such as plastic bullets may be used. Usually, controllers follow the training troops to help score additional kills, such as when a simulated grenade is thrown. They may do so with the MILES system using a controller gun. All these measures help to emphasize the importance of aimed fire, and taking cover. These concepts, while obvious, are often neglected in ordinary one-sided training exercises because the soldier does not suffer the consequences.