Battles that occur at close quarters, such as within a room or hallway, must be planned and executed with care. Units must train, practice, and rehearse precision room clearing techniques until each fire team and squad operates smoothly. Each unit member must understand the principles of precision room clearing: surprise, speed, and controlled violence of action.
a. Surprise. Surprise is the key to a successful assault at close quarters. The fire team or squad clearing the room must achieve surprise, if only for seconds, by deceiving, distracting, or startling the enemy. Sometimes grenades may be used to achieve surprise.
b. Speed. Speed provides a measure of security to the clearing unit. It allows soldiers to use the first few vital seconds provided by surprise to their maximum advantage. In precision room clearing, speed is not how fast you enter the room, rather it's how fast the threat is eliminated and the room is cleared.
c. Controlled Violence of Action. Controlled violence of action eliminates or neutralizes the enemy while giving him the least chance of inflicting friendly casualties. It is not limited to the application of firepower only, but also involves a soldier mind-set of complete domination.
Each of the principles of precision room clearing has a synergistic relationship to the others. Controlled violence coupled with speed increases surprise. Hence, successful surprise allows increased speed.
Multiple units clearing a room should not block their fire areas any longer than is necessary. In this example, the pointman, or first unit into the room, quickly moves across before setting up a field of fire that covers most of the room.
The backup unit, right behind the point, will stop short at the door, covering the far wall immediately behind the point man. The third unit, seen at the right side of the screen, will move past the point man while he is in the middle of the room, and into the corner covered by the backup unit, covering the final area and other point of egress/entry.
In this room clearing, the three marines had help from a medic who drew the unit's fire.
The third unit will keep moving to take up the final position shown below with the arrow. At this point, the enemy unit has been wiped out by multiple friendly units. Always gang up on the enemy, never take them on one on one.
Notice that all units are ready to move out of the building on the next turn upon completion, and all are facing the door, which is a threat axis.
