This training circular, Training Circular TC 7-100.3 Irregular Opposing Forces January 2014, is one of a series that describes an opposing force (OPFOR) for training U.S. Army commanders, staffs, and units. See the References section for a list of other TCs in this series. (Other publications in the former Field Manual FM] 7-100 series will be converted to TCs as well.) Together, these TCs outline OPFOR that can cover the entire spectrum capabilities of regular and/or irregular forces against which the Army must train to ensure success in any future conflict. Applications for this series of TCs include field training, training simulations, and classroom instruction throughout the Army. All Army training and red team venues should use an OPFOR based on these TCs, except when mission rehearsal or contingency training requires maximum fidelity to a specific country-based threat or enemy. Even in the latter case, trainers should use appropriate parts of the OPFOR TCs to fill information gaps in a manner consistent with what they do know about a specific threat or enemy. This publication applies y National Guard (ARNG) /Army National Guard of the United States (ARNGUS), and the United States Army Reserve (USAR) unless otherwise stated.