UNITED24 - Make a charitable donation in support of Ukraine!



This organization guide is part of the field manual (FM) series 100-60 that documents the capabilities-based Opposing Force (OPFOR). This series provides a flexible OPFOR package that users can tailor to represent a wide range of potential threat capabilities and organizations. The overall package features an armor- and mechanized-based OPFOR module and an infantry-based OPFOR module, each containing FMs describing organizations, operations, and tactics. Completing the package are FMs on OPFOR equipment and on other OPFORS in peace and conflict.

This introduction provides definitions of some basic terms used throughout the manual. For definitions of other key terms, the reader should refer to the index, where page numbers in bold type indicate the main entry for a particular topic. That page often includes a definition of the indexed term.


The OPFOR is a training tool for preparing the Army to respond to a wide variety of threats. The following paragraphs explain the difference between an OPFOR and a threat and the relationships between the two.

Threat and Country-Based OPFOR

A threat can be any specific foreign nation or organization with intentions and military capabilities that suggest it could become an adversary or challenge the national security interests of the United States or its allies. As the Army moves into the twenty-first century, it is no longer possible to identify one or two nations or forces as the potential adversaries against which it needs to train on a regular basis.

When conflict is imminent or when US forces need to train for a particular contingency, training may focus on a specified threat force. This rehearsal for an actual mission or operation can involve a country-based OPFOR. Such an OPFOR should portray the specified, real-world threat force with the greatest possible fidelity, based on the best available classified and unclassified information. Cases may exist in which constraints on the use of classified information or the lack of information, at any level of classification, preclude the use of actual threat data. To fill in gaps, in such cases, trainers could use those parts of the capabilities-based OPFOR that are most consistent with what they do know about a specific threat.

Capabilities-Based OPFOR

In more typical cases, however, the US Army simply needs to train against an OPFOR that represents a particular level of capability rather than a particular country. The capabilities-based OPFOR is a realistic and flexible armed force representing a composite of varying capabilities of actual worldwide forces. It constitutes a baseline for training or developing US forces, in lieu of a specific threat force. This baseline includes doctrine, tactics, organization, and equipment. It provides a challenging, uncooperative sparring partner that is representative, but not predictive, of actual threats.

The capabilities-based OPFOR represents a break from past practices on two principal respects. First, the armor- and mechanized-based and infantry-based OPFOR modules are not simply unclassified handbooks on the armed forces of a particular nation. Rather, each module has its basis in the doctrine and organization of various foreign armies. These OPFOR modules are composites deliberately constructed to provide a wide range of capabilities. Secondly, the modules do not provide a fixed order of battle. Rather, they provide the building blocks from which users can derive an infinite number of potential orders of battle, depending on their training requirements.

The primary purpose of these FMs is to provide the basis for a realistic and versatile OPFOR to meet US military training requirements. They can support training in the field, in classrooms, or in automated simulations. However, users other than trainers may apply these FMs when they need an unclassified threat force that is not country-specific.


The infantry-based OPFOR represents the armed forces of a developing country with limited resources. The name of that country is the State. The State's military structure consists primarily of ground forces. The formal name of this branch of the armed forces that corresponds to the US Army is the Ground Forces. These Ground Forces are primarily infantry (dismounted or motorized), with relatively few mechanized infantry and tank units and perhaps some air-borne infantry units. Aside from the Ground Forces, the State's armed forces may include any or all of the following components:

  • The Air Force, including the Air Defense Command.
  • The Special Operations Command, with commando and special-purpose forces.
  • The Navy, consisting of a small, brown-water force.

This OPFOR can also include less capable forces, to include internal security forces, the militia, and reserves. This menu of possible forces allows US military trainers to tailor the OPFOR order of battle to meet virtually any training requirement involving an infantry-based force.

Infantry-based forces are common throughout the developing world. These forces have some armor but rely on dismounted or motorized infantry for the bulk of their combat power. At the most, they conduct set-piece operations, integrating arms at the tactical level. None of these forces is capable of meeting the most advanced armies on an even footing in conventional battle. In many respects, the infantry-based OPFOR resembles the armies of World War I, with more lethal weaponry.

Size and Capability

The infantry-based OPFOR module includes a range of potential forces that can vary in size and capability. Small-to-medium infantry forces have marginal integration capability (ability to conduct tactical-level combat actions with limited fire support) or basic integration capability (ability to conduct battalion-level tactical combined arms actions). In terms of technology, both groups import most of their systems. Large infantry forces can conduct extensive set-piece operations over broad frontages. However, they are capable of projecting military power only within their region. The key technologies that can allow this are self-propelled artillery and offensive chemical and biological warfare. The State may or may not have chemical and biological weapons, but has the capability to produce or acquire them. A country with large infantry forces can have extensive, basic weapons industries, or it may still import most systems. Although this larger force may have improved communications, the OPFOR must rely on outside states for use of communications satellites.

When opposed by an adversary of similar capabilities, an infantry-based OPFOR can conduct conventional, force-oriented combat. However, when faced with a large, technologically advanced army, it is likely to attempt to redefine the terms of conflict and pursue its aims through terrorism, insurgency, or partisan warfare. In the case of intervention by an external power or coalition, this strategy aims to undermine the enemy's will to continue the conflict without the necessity of defeating his main forces on the battlefield.1

FM 100-63, infantry-Based Opposing Force: Organization Guide, depicts the forces of a country divided geographically into an unspecified number of military regions, each with a number of subordinate military districts. This OPFOR stations most combat forces within the military districts, which can vary widely in their strengths and capabilities. The guide allows for standing divisions, but districts with separate brigades would be much more common and in keeping with the spirit of the infantry-based OPFOR concept. At most, the State could mobilize and deploy one army-sized force capable of conducting large-scale operations against a neighboring country whose armed forces are also infantry-based. If the trainer finds himself building multiple standing divisions and armies, it may be that FM 100-60 better suits his training needs. He may find it necessary to draw some elements from both organization guides in order to constitute the appropriate OPFOR order of battle.

Compared to Armor- and Mechanized-Based OPFOR

The infantry-based OPFOR differs from the armor- and mechanized-based OPFOR primarily in terms of size, technological level, and the ability to integrate arms into operations. FM 100-60, Armor- and Mechanized-Based Opposing Force: Organization Guide, depicts the forces of a developed State with extensive resources devoted to maintaining a military capability that rivals that of the United States. It has a strategic capability, with strategic air and air defense forces and strategic missile forces. It probably has a nuclear capability. Unless the State is landlocked, it can have a blue-water navy and naval infantry (marines).

In the armor- and mechanized-based OPFOR, the ground forces are still the largest component. Compared to the infantry-based OPFOR, these ground forces have more standing divisions or brigades. Rather than being subordinate to military regions and districts, these divisions and separate brigades constitute several standing armies or corps. Most of these forces are in turn subordinate to army groups. Armies, corps, and army groups can vary widely in their strengths and capabilities. Even multiple army groups may come under a series of theater headquarters that orchestrate complex, large-scale operations.

The armor- and mechanized-based OPFOR can conduct a strategic operation involving the combined forces in a theater. These forces may comprise--

  • Several army groups.
  • Strategic nuclear forces (strategic missile forces and strategic aviation).
  • Strategic air armies.
  • National air defense forces.
  • A naval fleet.
  • Naval infantry forces.
  • Airborne forces.
  • Special-purpose forces.
  • National space forces.

Trainers may use any or all of these elements in an OPFOR order of battle as required.

Armor- and mechanized-based forces are the norm throughout the industrialized world. Such armies normally mount at least 40 percent of their forces in armored vehicles. They tend to modernize selected systems to match the best systems deployed by their neighbors. In terms of equipment and size, they range from small forces fielding outmoded equipment through large, capable forces fielding state-of-the-art weapons. For the most part, they still base their tactics and doctrine on World War II, either their own experience or that of their arms/doctrine suppliers. Many of these nations produce and export weapons and technology up through state-of-the-art-systems. Significant technologies that mark this class are in fire support and target acquisition.

Small-to-medium armor- and mechanized-based forces cover a wide range of technology and capability, from developing states through small, professional armies. Large armor- and mechanized-based forces often have more sophisticated weaponry: they field self-propelled artillery and multiple rocket launchers, artillery-delivered high-precision munitions, medium-to-heavy tanks, and limited thermal capability. This group may or may not have nuclear weapons but at least has the capability to produce or acquire them. Armor- and mechanized-based forces can conduct large-scale, combined arms operations. Joint operations are the norm in the more advanced states. These states have the logistics and command structures necessary to conduct continuous operations. Some armor- and mechanized-based forces are capable of sustained power-projection operations.

The high-technology end of the armor- and mechanized-based OPFOR approaches the level termed complex, adaptive forces. From developed nations, these most technically and tactically advanced forces can choose quality over quantity. As they modernize, they can reduce in size and still maintain a high level of military capability. These forces normally have a complex structure, with more specialized units operating highly sophisticated equipment. They are also capable of adapting to dynamic situations and seizing opportunities on the battlefield. However, such a force is exceedingly expensive to equip, train, and maintain.

Thus, the differences between the infantry-based and armor- and mechanized-based OPFOR modules are largely scenario-dependent. A particular training scenario may not require a large array of standing forces or justify the extensive use of mechanized infantry or tank forces. In such a case, it may be that FM 100-63 better fits the training needs.

Compared to Other OPFORs in Peace and Conflict

Compared to either of the OPFOR modules described above, other OPFORs in peace and conflict are less well defined. By their very nature, they are unpredictable. They too differ from the infantry-based OPFOR primarily in terms of size, technological level, and the ability to integrate arms into operations. In such a case, however, most military forces have lower capability than the infantry-based OPFOR. FM 100-66 depicts a variety of such forces that US forces may encounter.

On the one hand, these may be the forces of a preindustrial nation or a nonnation group with limited assets. Such groups cannot, or will not, invest in the weapons and technology necessary to keep pace with the best militaries in their regions. Most of their military organizations are ad hoc rather than standing organizations with predictable structures. These forces range in size from irregular forces, constabularies, and internal security forces to light infantry units. There is no such thing as a standard light infantry force; they come in all shapes and sizes. The common thread is that they have little or no organic, heavy equipment.

Like the lower end of the infantry-based OPFOR, these forces are likely to attempt to deal with a larger, more technologically advanced army through terrorism, insurgency, or partisan warfare. They do not try to meet such an enemy head-on in conventional combat. They prefer hit-and-run raids, ambushes, ruses, sabotage, and assassinations. They try to be unpredictable and invisible to view, employing methods not anticipated by their enemies. They do not fight by the rules of conventional warfare.

On the other hand, these OPFORs may also include forces that are better-equipped and better-trained. Such a force may be part of or sponsored by a wealthy criminal element or have the backing of a wealthy outside power. It may still be small and lightly armed but could have sophisticated, state-of-the art light weapons. The force is light not out of austerity but for practical reasons, because the lightness of the equipment enhances mobility. It may also have high-technology communications and reconnaissance means.

Lastly, there may be occasions where the OPFORs in peace or conflict include a sophisticated military organization with heavier weapons. If the US force is participating in a peacekeeping operation, for example, the OPFOR may be the recognized military of a belligerent nation. As such, it could include infantry-based or armor- and mechanized-based forces of the types found in FMs 100-63 and 100-60, respectively. Likewise, some of the types of OPFOR described in FM 100-66 can also appear during war.


The organization charts in this guide focus on maneuver units. They begin with the largest maneuver units and work down to the smallest. Whenever feasible, the guide breaks down subordinate maneuver units, as well as combat support and combat service support units, in greater detail.

Maneuver Units

Since motorized infantry units are the most common in this infantry-based OPFOR, these units come first in this organization guide. Such units differ from regular infantry primarily by having trucks available to transport all elements subordinate to the unit when necessary. The distinction between infantry and motorized infantry becomes clear only at brigade level, since the trucks for movement of infantry are organic to motorized infantry brigades. Within either type of brigade, the basic maneuver units from squad through company are simply infantry. At battalion level, there are no organic trucks for transporting any infantry companies, although the infantry battalion headquarters has a few. The motorized infantry battalion also has some wheeled vehicles in its signal and logistics support elements. At battalion level and higher, subordinate units common to both infantry and motorized infantry have their basic entry only under the motorized parent unit.

Following the infantry and motorized infantry units, in descending order of likelihood, come the mechanized infantry and tank units. Even an infantry-based OPFOR usually has some armored and mechanized forces. Again, any subordinate units common to both mechanized infantry or tank units and motorized infantry units do not repeat.

In OPFOR terminology, a separate unit is one that is not subordinate to a parent unit of the same arm. For example, a separate tank battalion is not part of a tank brigade. However, it may be part of a mechanized infantry brigade or directly subordinate to a motorized infantry, infantry, or mechanized infantry division. (The infantry-based OPFOR has no tank divisions.) Similarly, a separate motorized infantry brigade is not part of a motorized infantry division (or any division, for that matter). It is directly subordinate to a military district or an army. In contrast, a divisional brigade is always part of a division.

The basic maneuver unit is the brigade consisting of three or four maneuver battalions and a wide array of combat support and combat service support elements. Some infantry-based forces, however, may call the same organization a regiment. In this case, the difference in terminology is merely semantic and does not signify a different structure or capability.

Combat Support and Combat Service Support Units

Aside from organic combat support and combat service support units, Ground Forces maneuver units may receive additional support from the national asset pool. The General Staff/Ground Forces Headquarters can use such units, listed as national, to tailor support to various Ground Forces organizations. The numbers and types of units in the national asset pool can vary according to the situation. Their inclusion in this guide merely provides an option for, but does not mandate their inclusion in any order of battle developed from this guide. Users should determine the proper sizing and allocation of the national asset pool based on training requirements.

Flexibility Within Realistic Limits

Headings within each chapter indicate the name of the specific unit depicted and of all organizations to which this type of unit may be subordinate. Organization charts depict all possible subordinate units. If training objectives do not require the use of all elements shown in a particular organization, users can omit the elements they do not need. Some organization charts have blocks showing two alternatives for a particular type of subordinate unit. For example, a military district might have either an engineer company or an engineer battalion. In most cases, the unit listed first is the norm, but the other alternative is an option. Many organization charts have notes and/or footnotes that identify possible variations in organizational structure or equipment. These alternatives allow users to select the basic organization or the variation that best suits their training requirements.

Stacked blocks in the organization charts indicate multiple, identical units subordinate to a particular organization. Dashed blocks indicate units that may or may not be present in the type of organization shown.

Users must ensure that the size and composition of the OPFOR is sufficient to meet training objectives and requirements. However, total assets organic to a Ground Forces organization or allocated to it from higher levels should not exceed that which is realistic and appropriate to the training scenario. Skewing the force ratio in either direction negates the value of training.

Page References for Detail

In the main organization chart for any parent unit, subordinate units defined elsewhere in greater detail have page references beneath their block in the organization chart. This approach can lead the user to the subordinate unit, even if its organization chart appears in another chapter or another part of the same chapter. To avoid excessive duplication, subordinate units common to several types of parent unit receive detailed treatment only once, with subsequent cross-references back to that basic entry. Units without such page references do not have separate entries with further detail.

Occasionally, there may be a small unit that does not have its own organization chart showing further subordinates. However, the user may find a page reference leading to the parent unit's table of principal items of equipment, which breaks down equipment totals by subordinate units, including this one.


For organizations of brigade size or smaller, this book provides a table of principal items of equipment. For brigades and regiments, as well as selected battalions, this table provides a quick overview of the holdings for subordinate units and equipment totals for the unit as a whole. Units above brigade/regiment level either have no fixed structure or have so many variations in possible structure that equipment totals are difficult to quantify. Therefore, the organization guide leaves those specifics to users who build actual orders of battle for a specific OPFOR in a specific scenario. The OPFOR order of battle must meet the user's training requirements, based on the menu of possible organizational parts provided in this manual.

Equipment totals include individual weapons only at maneuver battalion level and below. The same is true of night-vision devices (goggles and sights). These figures vary widely from unit to unit, although separate brigades tend to field more goggles in combat support and combat service support units than do divisional brigades. With the exception of maneuver units (battalion and below), accounting for the varying numbers of night-vision devices, especially the goggles worn by vehicle drivers, is difficult.

This guide provides example equipment types and the numbers of each type typically found in specific organizations. The purpose is to give users a good idea of what an OPFOR structure should look like. However, training requirements may dictate some modifications to this baseline. Users should exercise caution in modifying equipment holdings, since this impacts on an OPFOR unit's organizational integrity and combat capabilities.

Baseline Equipment

A developing country may equip its infantry-based OPFOR primarily with systems imported from more advanced, weapons-producing countries. For illustrative purposes, the equipment lists in this manual show systems produced by the former Soviet Union (FSU). There are two reasons for using FSU-produced equipment as the baseline. First, many potential threat countries have equipped their armed forces with systems that the FSU and its successor states have built in large numbers and proliferated widely throughout the world. Second, this equipment is representative of a unit's or force's technological capability. Listing these familiar, well-documented systems paints an immediate, concrete picture of that capability. Listing generic equipment descriptors, such as medium tank or antitank guided missile, would not create such a clear impression of capabilities. Moreover, generic descriptors would not lead to the development of consistent equipment sets. This organization guide, therefore, normally uses generic descriptors only when the choice of systems would not materially affect basic unit or force capabilities.

Equipment Substitution

To achieve specific training objectives or merely to provide variety in the training environment, users can substitute other equipment for those listed as the baseline. Appendix A contains matrices with suggested examples of appropriate substitutions for major maneuver and fire support systems. Appendix B does the same for engineer equipment. Appendix C lists examples of cargo trucks, trailers, and radios corresponding to the generic descriptors used in equipment lists. Each appendix also provides general guidelines for the substitution process.

Appendixes A, B, and C are guides; they cannot be all-inclusive, listing every conceivable system available worldwide. In constructing an OPFOR order of battle, therefore, trainers may substitute systems not listed in the appendixes. However, they should follow the same general philosophy and the guidelines prescribed in the appendixes. To assist in the substitution process, FM 100-65, Opposing Force Equipment Guide, will present a wider selection of major systems from which users may choose.

1 Throughout the FM 100-60 series, the term enemy refers not to the OPFOR but rather to the enemy of the OPFOR.

Join the GlobalSecurity.org mailing list