In a zombie outbreak, there may be many times when one (hopefully with a small contingent of armed survivors) will have to inspect a building or structure where there may be zombies lurking. Possible reasons include (but are not limited to) establishing a new shelter, scavenging for supplies, rescuing a trapped person, or simply retaking the area, one house at a time. Fighting zombies indoors puts survivors at a disadvantage. The advantage of killing at range may be greatly diminished. It can be difficult to wield melee weapons in unfamiliar or confined quarters, and the risk of wounding fellow survivors is greatly increased. Disciplne, attentiveness and solid leadership are crucial.
The following tactics are derived from official US Military and Tactical Law Enforcement unit procedures.
Using the right equipment for sweeping rooms is also essential. Many firearms that work wonderfully at range (such as an M16) are fairly clunky and awkward to wield through hallways and doorframes. Sub-machine guns are probably one's best bet, though the value of handguns rises dramatically when fighting inside. As always, conserve ammunition and increase accuracy with short bursts of fire.
Shotguns can be problematic when sweeping unknown rooms. The spread of the buck shot can very easily pass through thin walls, and around/off to the side of targets. And slugs at close range can likewise pass in and out of the target, hitting unknown allies, or combustable materials. Only advanced firearms users should even consider using shotguns indoors.
Other valuble equipment includes flashlights and hard armor around the arms, head, and neck (for overall bite resistance, if entangled with a zombie), crowbars, sledgehammers, battering rams, or fire axes (in case of locked doors, or barricades).
Having clearly defined roles is also vital. Every team needs a squad leader. This is usually (but not always) the main decision maker of the group. The team also needs a pointman. The pointman is the first person through the door. It is generally inadvisable for these two roles to be held by the same person. The squad leader's primary responsibility is the bigger picture of the squad's mission, and their safety. The pointman must ignore the bigger picture, and focus entirely on whether to fire on a threat, or spare an innocent in a split second. The squad leader is like a head coach or manager, and the pointman is a team captain.
A third popular choice of a defined role is that of door buster, or door man. Usually a strong man, the door buster's only responsibility is breaking doors.... or sometimes making new ones. Large blunt force is always used. The use of contained explosives (such as breaching charges) is considered a poor investment in time and valuble resources.
All other squad members should be divided into "buddy" pairs or trios. At all times, they should stay with their buddy (as in the buddy system) or group, never moving out of line of sight. One is responible for the safety of their buddies at all times. One pairing should also take responsibility for the pointman.
Initial Entry Edit
Whenever possible (and practical), entry to an unsecured structure should be preceded by a sweep of the perimeter. This can yield all sorts of useful information, such as additional entry/escape points, a rough idea as to how many zombies may be lurking, and whether to expect zombies in the area to be attracted to the commotion caused by the squad's taking of the structure.
Ringing the Dinner Bell Edit
If time and safety permits, the best way to clear a structure is to eliminate as many zombies prior to entering. Shouting amiable and non-aggressive declarations is a great way to do two things simultaneously. The first is awaken the zombies inside to the prescence of the squad, and lure them into door and windowframes. These are excellent bottlenecks, and should be where most of the squad directs their attention (though the squad leader should always be scanning the horizon for possible nearby ambush points, and the like).
The second thing this accomplishes is establishes a line of communication with other survivors in the area. Be aware, some may come to the window or door, so itchy trigger fingers may yield civilian casualties, maybe even a firefight for which the squad will be grossly out of position for. Shouting at an unknown building, while wielding weapons, is a hostile act by nature, so do not expect every survivor to react in compliance. But one should expect every zombie within earshot to make themselves known. As previously mentioned, this is not always practical.
Entry Positions Edit
Typically, the squad leader stands back; close enough to have his instructions heard, but far enough where he cannot impede them. The doorman stands to one side of the door. The pointman is on the other side. The rest of the team forms either one single file line to one side of the door, or two lines, one on each side.
When the squad leader gives the signal to start, the door buster opens or destroys the door, and stands back (or makes himself small, to allow the team to flood in around him). The pointman leads, eliminating any forward or otherwise immediate threats. The pointman should try to stay low, in case the member behind him sees something, and needs to shoot close to the pointman, or perhaps just over his head. Once enough space is secured on the other side of the entrance, the pointman steps to a near, safe corner, and calls for the rest of the team to flood in. Each pair enters, and rolls out together, but the opposite of the direction the previous pair (EX: The Pointman went in, rolled to his left. The first pair follows, rolls right, the second pair follows, rolls left.). One's foot placement and pace of stride should never be far from the forefront of one's mind - an errant step or trip could put the team in danger.
The team spreads out to cover all sight lines, and eliminate all threats. The door man and the squad leader enter after the all clear sign is given by the team. A shortened repetition of this procedure is repeated for the following rooms. In larger or complex structures, a way to mark secured rooms (such as spraypaint, or magic marker) should be employed. Casualties are to be ignored until the entire structure is cleared.
Silent Variations Edit
If the squad has been traveling through an infested zone with stealth, they will likely have to continue to employ stealth while securing the structure, as reinforcements for the zombies will be just a moan or scream away. Most verbal communication will have to be substituted with hand signals. Firearms may not be practical. The squad leader will have to be very alert to zombie moans; both from within the structure, and perhaps within the immediate area.
Undermanned Squads Edit
One of the main reasons this general tactic is employed is because most threats (with the exception of initial threats handled by the pointman) are engaged by two or more survivors at a time. Some small groups, or solo survivors may not have this luxury. A survivor with these additional obsticles should try to keep as low a profile as possible, and be as sensitive to his surroundings as possible. If discovered, one should attack aggressively and swiftly, to prevent the zombie moan from attracting a horde of zombies as best as possible.