Military operations in urban terrain - Core Infantry - United Task Force (UNITAF) Arma 3

P3-11 Military operations in urban terrain

UNITAF / Arma 3 / Core Infantry Procedures

Version 1 / 11min read / Updated Tue 25 Feb 2020 / 638 views

Military operations in urban terrain (MOUT) and close quarters battle (CQB) is easily the most dangerous environment for infantry to operate.

Threats can come from above, or appear and disappear in an instant in the urban clutter. The fighting is fast, violent, and confusing. Good communication is needed at all levels to provide timely information as well as avoid friendly fire incidents. MOUT combat must be done at a deliberate, methodical pace, and all elements need to be able to move in a cohesive manner that prevents anyone from getting cut off or lost, and maintains a very high level of situational awareness and defensive cohesion.


There are several tips for the infantrymen operating in these environments.


Maintaining 360 security before clearing a building


  • Stay aware of the vertical element in a MOUT environment.
    Enemies can be on the rooftops, and it requires sharp observation from all players to spot them before they can do harm.
  • Know your sector of observation/cover and be diligent in watching/covering it.
    One person letting their guard down for a few seconds can doom many.
  • Pie off all danger areas.
    Pieing is simply the process of moving carefully and deliberately in a fashion that allows you to see as much of an area as possible before entering it. This has a multitude of uses in all areas of combat, but becomes particularly important in MOUT/CQB with buildings and streets. Pieing a room allows for you to visually clear everything except for a corner or two, which allows you to enter and immediately focus on the danger areas (ie uncleared corners) without having to do a full sweep of the rest of the room at the same time.
  • Stay off of the walls.
    Walls act as backdrops for explosive rounds to detonate on, and being too close to them will make it that much easier for an enemy to lob a grenade or rocket your way and take you down. You will constantly face the dilemma of whether being close to a wall will provide protection or put you at extra risk - weigh the options quickly and pick the best one for the scenario.
  • Stay out of the open.
    Move from covered position to covered position, and avoid lingering in the open. Streets are natural kill zones in urban areas and are frequently covered by machineguns.
  • Be aware of the danger of ricochets.
    Traveling down a narrow alleyway can become even more dangerous when rounds being fired at you start ricocheting off of the ground and walls to wreak even more havoc. Cannon rounds, such as those from an Infantry Fighting Vehicle's (IFV) main gun, are particularly deadly when they begin to ricochet.


Video: Perform Exterior movement Techniques During an Urban Operation (A visualization depicting the Soldier’s Manual of Common Tasks (STP 21-1-SMCT) task Perform Exterior movement Techniques During an Urban Operation (071-COM-0541). This was developed for the Center for Initial Military Training, FT Eustis, Va. This visualization has been approved for public release.)


Clearing a Building

Clearing a building is one of the most dangerous tasks a team can be assigned, requiring a team-wide solid understanding of CQB tactics in order to successfully carry it out.



Covering & Clearing Teams

In order to effectively clear a building, an element must split itself into two parts - one is the covering team, which provides security outside of the structure. The other is the clearing team, which actually goes into the structure to clear it out room by room. The cover team is typically the Fireteam Leader and the automatic rifle/assistant pair, while the clearing team consists of the fireteam's riflemen.

The clearing team must know the plan in advance of reaching the structure’s entry point. Communications should be quiet and over the radio whenever possible, to avoid telegraphing your intentions to any potential defenders.

The clearing team picks an entry point in advance and from a distance, followed by a cover team laying down smoke concealment or suppressive fires when possible, which is then followed by the clearing team rapidly moving towards and breaching through the entry point.


The cover team is responsible for:

  • Suppressing the building while the clearing team moves into position
  • Suppressing floors that the clearing team is not on
  • Communicating with the clearing team to coordinate said suppression
  • Preventing any hostile forces from exiting the building


The clearing team is responsible for:

  • Moving methodically through the structure room-by-room until it is cleared of hostile forces
  • Communicating their movements to the cover team so that the cover team can shift fire accordingly


There will be times when players must enter and clear a room or number of rooms due to the tactical situation. In order to pull this off successfully, players should be familiar with the basic room clearing procedures.



Entry & Stack Methods

When it comes to making entry into a room, the members of the clearing team have two options.

Hook - In this, the player moves into the doorway and then immediately hooks to the side that he had been 'stacked up' on. For instance - if the player is on the right side of the doorway, he will enter through the doorway and immediately turn right.

Cross - In this, the player moves through the doorway and continues opposite of the direction he had been 'stacked up'. For instance - if the player is on the right side of the doorway, he will move through the doorway and cross to the left side once inside the room.

There are two ways that a 2-man stack can 'stack up' on a door - one is with both members on the same side of the doorway ("stack"). If this is the case, the first man will state his entry type ("Cross!" or "Hook!"), and the second man will do the opposite, to ensure proper coverage of the room. This type of stack is best used when an open door is present. If the entry type is not stated, the second man simply does the opposite of what the entry man does.

When ordering a stack, the lead man will either say "stack left" or "stack right" - the directions are relative to facing the doorway. "Stack left" will result in the entry team being on the left side of the door.



2-man left-side stack

The other option is to have one player on either side of the doorway ("split stack"). The senior player will state his entry type, and the other player will prepare to do the same type of entry, except from the opposite side of the door. This type of stack is best assumed when a closed door is present - movement across an open doorway for the sake of setting up a 'split stack' should never be done.


2-man split stack

Being fluid in movement and stacking is more important than making everything look by-the-numbers. Taking the time to do a 'pretty stack’ outside of a structure can be fatal in an intense urban fight and should generally be avoided when the surrounding area is not firmly in friendly control - instead, focus on being fluid and fast. The entry team should be able to rapidly adapt to the situation at hand with a minimum of communication and spend as little time "at the door" as possible. Flow to the door, through it, and through the structure.


Room Clearing Procedures

When the stack is set, the next step is to actually carry out an entry from start to finish. For this, the following steps act as a guideline for how a typical room take down occurs.

  1. Ensure your weapon is on full-automatic with a fresh mag
  2. Throw a flashbang or a fragmentation grenade into the room, if available and no friendly or civilian forces are potentially inside.
  3. Each player enters in sequence, engaging targets to their front as they move through and out of the 'fatal funnel' that is the doorway.
  4. After moving through the doorway, each player continues in the direction prescribed by their entry type (hook or cross), clearing from his front to the corner he is moving towards.
  5. Players must continue to move into their 'corner' regardless of the amount of enemy fire received - continuing to push to their corner will draw fire towards them, allowing the following members of the stack to successfully enter the room and begin engaging the enemy.
  6. After clearing his 'near' corner, he continues moving towards it while pivoting to clear the wall that runs to his 'far' corner.
  7. After clearing the far corner, he clears to the center of the room, then clears to the other side of the room, stopping short of where his teammate is.
  8. Once the room is deemed clear, each player uses direct speaking to announce "Clear!" to his teammate. If the situation requires, communication may be absent for security's sake. When working against enemy players, staying quiet while clearing a building will prevent the enemy from knowing your status, location, and intent.
  9. From here, movement through the structure is careful and deliberate, with rooms being pied off, doorways covered, and each member of the team taking their time to carefully clear their way through.


The entire process, from start to finish, happens in a few seconds at most. Knowing how to enter rooms properly should prepare you for the most common CQB situations you'll encounter in the game. Note that if you are using a covering team outside of the building, the clearing team should state loudly that they are "coming out" of the structure before doing so, to ensure that the covering team does not mistakenly engage them.



Crossing Urban Danger Areas

Every team member needs to be familiar with what to do when dealing with danger areas in the urban environment. Due to the chaotic and fast-paced nature of urban combat, there are no strict roles for each fireteam member to take when crossing urban danger areas. Instead, roles are based upon where in the formation a given person is, regardless of their fireteam role.


An team leader rushes across a danger area as an automatic rifleman provides cover


When moving up to a street danger area, the first person in the formation will stop at the corner, scan both directions, take a knee, and then say "Set!" via direct-speaking. The second person in the formation will then move up, make his own scan, and decide on how he will move across. When he is ready, he will say "Crossing!" and then rush across the danger area. The remaining members of the fireteam will follow across at intervals of their choosing, based upon whether enemy fire was received and various other considerations. The last to cross will say "Last man!" to let the cover man know that it will be his turn to move next. The last person to cross will be the cover man, who was the first person to have reached the corner.


A squad works through the urban environment, covering their own movements as they go


Other Urban Tactics

High/Low Corner Stack

When covering corners, if one player kneels while another stands behind them, two pairs of eyes and two rifles can cover the same area, increasing effectiveness. This is commonly known as a "high/low stack" and can be employed naturally whenever the situation allows. Note that the kneeling player must not stand unless he has cleared it with the standing player - else he's likely to stand up into a bullet.

UNITAF Standard Operating procedures (SOP)
are adapted primarly from US Army Training and Doctrine Command (TRADOC). Our written and audio procedures are a combination of the following primary source materials, as well as our own learnings, modifications and adaptations:
- US Army Techniques Publication, Infantry Platoon and Squad (ATP 3-21.8)
- Soldier’s Manual of Common Tasks Warrior Leader Skills Level 2, 3, and 4 (STP 21-24-SMCT)
- The Warrior Ethos and Soldier Combat Skills (FM 3-21.75 / FM 21-75)
- Leadership Development (FM 6-22)
- Dyslexi's Tactics, Techniques, & Procedures for Arma 3 (TTP3)

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