Heavy Armor soldiers are outfitted with a heavy and cumbersome alloy armor suit, giving them a large degree of protection, but drastically reducing their speed and maneuverability. They are armed primarily with the HV Penetrator nail gun, although some are deployed with the Type-7 Particle Weapon or the MOD-3 Multi-Rocket Launcher.
Highly durable, a Heavy Armor can survive roughly 6 times as much damage as a normal Replica soldier and can often endure more than a full magazine's worth of weapons fire from most firearms. They also appear to have some degree of superhuman strength, as they are occasionally seen bashing through (and warping the shape of) locked metal doors and thin walls.
It is unclear how intelligent Heavy Armors are, as they do not converse with other Replica forces and make only limited use of their surrounding environments for cover. What is known about them is they can rush for a limited time at the Point Man if he is in close proximity and they can use a melee attack, consisting of swiping the side of their weapon at the player. Heavy Armors are not as aggressive compared to most of the other Replica forces (as their armor prevents them from moving fast and effectively) so they usually are in a defensive stance instead. In harder difficulties, Heavy Armors have better accuracy and are more likely for them to hit the Point Man even when he is using Slow-Mo.
They are sporadically referred to by Replica soldiers simply as "Heavies" and "Armor," such as the remarks of "The armor's down!", or "He took out the Heavy!"
They are significantly taller and larger than other Replica soldiers and, when either the Point Man gets close to them or if they are killed, Heavy Armors will emit a loud growling/wailing sound that seems inhuman, although it is never made clear what the sound is. It is interesting to note that, at the end of the low-pitched scream, unclear radio communications can be heard which quickly fade to static and then stop.
The Heavy Armor Mk-7 has been redesigned entirely in F.E.A.R. 2: Project Origin. The suit itself is much bulkier; it now appears to be closer to a power armor than a suit of heavy armor, the plating clearly much thicker and the suit collar resembling those used by bomb disposal suits. The five blue "eyes" have changed to seven white ones; the "face" now consists of a large central light with four smaller ones arranged in a rectangle around it, with two parts of the main circle at around eye-level sectioned off and extended outward as separate, slit-like "eyes." Mounted on the shoulders are another ten lights; two large ones and a semicircle of smaller, variously sized lights below. Two further lights are mounted on the backs of the forearms.
Often, Michael Becket will see these powerful soldiers ramming through walls to make way for the other Replica forces. Only thirteen Heavy Armors are encountered in Project Origin; three are equipped with the Shark FL-3 Laser, one carries the Andra SR5 Missile Launcher in Interval 07 - Climax, while the rest are equipped with Armacham HV Hammerheads. They also come equipped with Incendiary or frag grenades, and will occasionally use them if their target is hiding behind cover. Heavy Armors will occasionally drop an XS Shock Grenade if the player runs short.
An Armacham Technology Corporation logo and the serial number "B-CA9Z" are visible on a plate mounted on the suit's chest.
They require several magazines of shots from most weapons, but the Andra SR5 Missile Launcher is very effective, with one rocket and half a magazine from the assault rifle being capable of killing them in most situations, or two direct hits will kill them. Sniper rifles requires three headshots to kill, and Laser will take about 40% of the battery to kill one. The Hammerhead is a good choice if the player is short in firepower, it takes about 18 rounds to kill one. If possible, use shock grenade first to buy players some time to fire without reprisal. Grenades, headshots from the Raab KM50 Sniper Rifle, or any type of armor piercing weaponry (HV Hammerhead, Shark FL-3, Type 12, etc.), are recommended. All other small arms should only be used as secondary weapons against a Heavy Armor.
Heavy Armors are encountered in Reborn but appear in larger numbers than previously seen. One encounter pits the player against six of them, however, only two are fought at one time, and none of the Heavy Armors carry the Shark Laser. Later on, there will be one more encounter with them in a large open area where Foxtrot 813 will fight three more (with their signature weapon), and a fourth using the rocket launcher. The second fight is one of the hardest in the game, as the player will be fighting them alongside regular Replicas while Snipers support them. There is a heavy mounted weapon near the middle of the area, but getting to it might make the battle harder, as there is no cover there.
A few Heavy Armors can be encountered in the Tunnel campaign scenario.
Though Heavy Armors are not encountered in the game, the Phase Commanders seem to replace their vacant role.
In F.E.A.R. Extraction Point, a Heavy Armor is seen knocking down a concrete subway wall. Also in Extraction Point, a new type of Heavy Armor soldier, the Heavy Riot Armor, is introduced, carrying a riot shield which resembles a massively extended version of the normal Heavy Armor's large rectangular shoulder pads, and a TG-2A Minigun. In Extraction Point and Perseus Mandate, the Heavy Armor is almost never seen fighting alone, and is either accompanied by regular Replica Soldiers or come in pairs.
Heavy Armors and Heavy Riot Armor soldiers also appear in F.E.A.R. Perseus Mandate, though not as frequently as the first game, as the Nightcrawlers are now the primary enemy. While the Heavy Armor is still primarily issued the HV Penetrator, they also carry heavy weapons such as LP4 Lightning Arcs and K3-BT Grenade Launchers. Two of them also carry G2A2 Assault Rifles. The player still need to fight them with caution as they are the most dangerous unit in Replica Forces, along with Heavy Riot Armor, REV6 Powered Armor and LEV8 Leviathan.
- In Perseus Mandate, a few corpses of them can be found around the Train Yard, presumably killed by Nightcrawler forces, this is the only time you will ever see dead Heavy Armors that weren't killed by the player.