Hazardous Environment Combat Unit

"Forget about Freeman, we are cutting our losses and pulling out! Anybody left down there now is on his own, repeat, if you weren't already, you are now fucked!"

- HECU soldier

The Hazardous Environment Combat Unit, often abbreviated as HECU, is a fictional United States Marine Corps Special Forces Unit featured prominently in Half-Life and its expansions.

Overview
The Marines of the HECU are specially trained to deal with a variety of indoor combat situations, particularly involving a dangerous environment and unconventional enemies. Members of HECU are trained by drill instructors Dwight T. Barnes and Sharpe, and train at bases guarded and staffed by members of the Military Police. The Marines are often referred to as "grunts" by fans of the game and also as such by Black Ops Operators in the game.

With the Black Ops, they are part of a "dangerous and very efficient clean-up crew" sent to Black Mesa in case of emergency, and are supposed to work in concert with the Black Mesa Security Force in these cases.

In the Half-Life Audio Script, the HECU Marines are described as follows: ''Human military units sent in to "clean up" the base following the disaster. It is their job to execute anyone with knowledge of the research project that went awry. The more you know about the project, the more they want to kill you. They especially hate you, Gordon Freeman, personally - because you have cut down quite a few of their buddies.''

They are featured in Half-Life, and its expansion packs, Opposing Force, Blue Shift, and Decay.

Half-Life
Following the catastrophic Resonance Cascade at the Black Mesa Research Facility, bizarre aliens from Xen teleport into the complex and begin attacking personnel. The Hazardous Environment Combat Unit is dispatched to the facility to fight the aliens and regain control of Black Mesa. Unknown to the surviving personnel at Black Mesa, though, the Marines have also been ordered to eliminate Black Mesa's civilian personnel to ensure that the incident is covered up. The HECU rapidly takes over the surface areas of Black Mesa using their V-22 Ospreys to drop in men and then dispatches forces into the interior to eliminate the aliens, Black Mesa Security Force, and bring important members of the Science Team up to the surface for brutal interrogation. Many Marines disagreed with their orders.

The HECU's initial foray into Black Mesa was highly successful: the Marines quickly gained an advantage over the confused and frightened survivors and aliens and established a substantial presence within the facility. Black Mesa's civilian personnel failed to put up any notable resistance, as many personnel mistakenly believed that the Marines were there to rescue them, and those who tried to defend the facility against the HECU were hopelessly outgunned and overwhelmingly outnumbered, having already been weakened by the Xen creatures. The HECU soon took control of Black Mesa's central command areas and issued orders over the public address system for the facility's remaining personnel to cooperate and submit to interrogation. The troops began fortifying key surface areas with sandbags, mounted machine guns, and fixed artillery. Although there were few of them, there were also some snipers, one of which shot at and fatally wounded a security guard.

The tide soon turned against the HECU, though, as the Xen aliens continued teleporting into Black Mesa in overwhelming numbers. Surviving facility personnel lent their help to Dr. Gordon Freeman, who was able to sneak and fight his way across the facility despite all the HECU's actions, being responsible for many casualties on their side. Freeman quickly became a priority target of the troops. Their anger toward him was exemplified by several sets of graffiti seen in the "On A Rail" chapter of the game, which read "YORE DEAD FREEMAN" [sic], "SURRENDER FREEMEN" [sic], "DIE, FREEMAN" [sic], the latter of which is accompanied by 1 or 2 tripmines. Also in the same chapter two Marines can be heard talking about Freeman and their proposed revenge for killing so many of their friends, ignoring the irony of what they themselves had been doing. Their conversation also hints that the Marines mistakenly believe Freeman (and by extension, the whole Black Mesa Science Team) intended to cause the Resonance Cascade.

The full conversation is as follows:

As the battle raged on, the Xen aliens began to gain the advantage and the HECU, which was sustaining appalling casualties, was evacuated as aerial bombardments tore into the facility. The evacuation was woefully incomplete, however, leaving many Marines behind in the facility (in blatant violation of the policy never to leave another Marine behind) in the unenviable position of being caught amongst the forces of the Black Ops, the Xen aliens, the newly-arrived Race X creatures, and a still active Freeman.
 * "So, who is this guy, Freeman?"
 * "They say he was at Ground Zero."
 * "Science Team? You think he was responsible, sabotage, maybe?"
 * "Yeah, maybe. But one thing for sure is he's been killing my buddies."
 * "Oh yeah, he'll pay. He will definitely pay."

Still, the HECU was aware of this happening to some degree, as a soldier was able to send one last radio transmission to any stragglers underground.

Half-Life: Uplink
During Gordon Freeman's run to the satellite array and the later return trip, Gordon makes his way through an HECU camp in the shipping yards which consists of multiple weapon emplacements, troops in towers, a command tent, and a pit dug for burning dead Vortigaunts.

Half-Life: Opposing Force
In the original Half-Life game, the Hazardous Environment Combat Unit was simply referred to as "the military" or "soldiers". In the expansion Opposing Force, the protagonist, Corporal Adrian Shephard, is one of those men, and during the opening titles that display his personal info, his training is listed as "USMC Special Forces" and his current assignment is listed as the "Hazardous Environment Combat Unit, Santego Military Base, Arizona". Many new models are included, notably two precise classes: the Engineer, assigned to cut open sealed doors using a welding torch, and the Medic.

Opposing Force takes place several hours after the initial resonance cascade. Adrian Shephard, is knocked unconscious when his Osprey transport is shot down by Xen forces, and wakes up several hours later in the Black Mesa Infirmary. Shephard regains consciousness just in time to witness the HECU begin to pull out all of its troops. However, he is prevented from leaving when the mysterious G-Man seals him in the facility. Shephard is forced to continue deeper into Black Mesa, where he encounters and takes charge of the remnants of HECU who have also been left behind during the evacuation. Shephard and his men find themselves combating not only the aliens from Xen, but also the newly arrived "Race X" aliens and a group of government Black Ops assassins who have recently been dispatched to the facility, who appear to have orders to eliminate any remaining HECU Marines as well as to destroy Black Mesa with a nuclear device.

The Hazardous Environment Combat Unit also appears to have access to more advanced military technology than their regular counterparts, as the Marines wear Powered Combat Vests (PCVs) and employ automated HECU Sentry Guns.

Furthermore, in both games, the troops are deployed in Osprey aircraft, which at the time of the game's production, had not yet gone beyond Engineering and Manufacturing Development (EMD) and low-rate production with the United States Marine Corps.



Murphy's Combat Laws
These actual Murphy's laws are included in the Opposing Force instruction manual, written as a soldier's handbook.

Half-Life: Blue Shift
In Blue Shift, the HECU is first seen in the chapter Duty Calls, where two soldiers are seen dumping security guard corpses above Sector G's Drainage Canal. They are prominently seen in the next chapter, Captive Freight, where they are swarming the Freight Yard, have trapped Rosenberg and many other scientists in containers, and fatally wounded Harold. In the next chapters, Power Struggle and A Leap of Faith, set in and under the Section A-17 Prototype Labs, they do everything they can to stop Barney, Rosenberg, Simmons and Walter from escaping the facility by teleportation, but they ultimately fail.

Half-Life: Decay
In Decay, the HECU is first seen in the Level 3 Dormitories, during the chapter Domestic Violence. A dying security guard warns the players that they are everywhere. Gina and Colette continue through the level, seeing the aftermath of the HECU's invasion. They eventually get to the Library, which they have to clean up from the soldiers so that they can bring a security guard to Dr. Keller. The HECU is seen in the next chapter, Code Green, in the Black Mesa Air Control. There many are offloaded by an Osprey and attack Gina and Colette while they attempt to enter the clearance codes given by the security guard picked up in the Level 3 Dormitories. They are seen again in the next chapter, Crossfire, in the sewers under the Gamma Labs, where they guard the Displacement Beacon Focus Emitter. They are finally seen in the bonus chapter, Xen Attacks, in the underground parking lot located under the Ordinance Storage Facility where R-4913 and X-8973 must retrieve the Xen crystal samples.

Weapons and equipment
The Hazardous Environment Combat Unit troops, while utilizing a variety of equipment and firearms, are all equipped similarly. Each Marine is equipped with Urban Camouflage BDU, a Powered Combat Vest and can be equipped with a PASGT helmet with M81 Woodland Camouflage.

The primary weapon assigned to each HECU trooper is indicated by their character model.
 * Gas-mask (standard): MP5 submachine gun
 * Balaclava (shotgun soldier): SPAS-12 Shotgun
 * Smoking Cigar (demolitions): MP5 submachine gun with attached grenade launcher
 * Beret (squad leader): MP5 submachine gun with attached grenade launcher, or shotgun

Weaponry
The HECU use a wide variety of weapons, for various purposes. Most of these weapons are based on real-life weapons. Some of the following weapons cannot be used by the player.

Personal weapons

 * Glock 17 (Beretta M9 in the HD pack)
 * Desert Eagle
 * MP5 with attached grenade launcher (M4 in the HD pack)
 * M40A1 Sniper Rifle
 * SPAS-12
 * M249 Squad Automatic Weapon
 * RPG
 * Laser Tripmine
 * Mk 2 Grenade
 * Combat Knife
 * Satchel Charge

Fixed weapons/heavy artillery

 * Autonomous Sentry Gun
 * M198 Howitzer
 * M2 Browning Machine Gun
 * Unidentified double and simple sandbag turrets (cannot be used by the player)
 * M202A1 FLASH

Other

 * Dynamite (Cannot be used by the player)
 * Land Mines(Cannot be used by the player)

Vehicles


The HECU use many standard ground and air vessels.


 * AH-64 Apache
 * V-22 Osprey
 * M1A1 Abrams
 * M2A3 Bradley
 * F-16 Fighting Falcon
 * M35 cargo truck

Technology
The technology used by the HECU is mostly based on conventional and unconventional military practices such as vehicle support, artillery support, fortification and traps.


 * Powered Combat Vest
 * Tactical Map
 * Welding Torch
 * Radio

Tactics
The HECU use several techniques and tactics over the course of Half-Life, ranging from setting traps and the use of turrets to use of heavy vehicles and air strikes. The standard infantry tactics include using numbers to pin down the player and then advancing, and occasionally tossing grenades to either kill the player or force him to come out of hiding. They also use heavily fortified mounted turrets on several occasions. Spotting and then attacking them before they they do the same is crucial for victory. Being as they like to shoot until the player retreats, and then advance, strategically placing trip mines behind and then retreating is a good way to take them down. If the HECU are occupied with fighting other forces (such as Xen aliens), then taking the time to place a Satchel Charge will be a benefit once they draw their attention to the player. The HECU are prone to use of vehicles to kill or distract the player in later levels, and it is often best to take out the infantry first in order to be able to focus all attention on the vehicle. It is worth noting that in some levels the HECU will also use snipers to cover an area. The snipers can be deadly if the player is caught off guard or ventures in the open area unaware of the snipers presence. The HECU are also prone to laying laser trip mines and turrets in unsuspecting places, especially around blind corners and cramped areas, so the player should be wary of both of these, as it is very easy to fall into these traps. Using the shotgun and SMG on HECU troops is also very helpful, as the soldiers use these weapons themselves and will drop valuable ammo. Soldiers will also melee attacks, kicking the player if they get too close.

Behind the scenes

 * Originally, some HECU soldiers were to be smoking. It was cut but brought back in Opposing Force. The non-HD black beret model still features a cigar, however.


 * Originally, the HECU was to feature a powerful minigun-wielding soldier, smoking a cigar, nicknamed the "Human Sergeant" [sic].


 * Early concept art for the Half-Life chapter Surface Tension suggests that a large HECU camp was considered at some point.


 * Originally, the HECU was also to operate a F-117 Nighthawk.


 * In Half-Life: Day One, there are only soldiers with gasmasks and berets. They also do not use the shotgun.


 * Chuck Jones designed the original models, while Stephen Bahl designed the new classes (Medic, Engineer) and variations for Opposing Force, as well as all the HD models. For Opposing Force, Gearbox's purpose was to improve upon what Valve had created with new versions/classes, since a lot of the game was with soldiers.


 * The HECU was also to feature robots among its ranks, such as the Robot Grunt. It can be found in the Half-Life SDK. A bronze-colored version was reused for Half-Life Deathmatch. The grunts were also used for the censored German Version of the game, replacing all the soldiers.


 * Originally, the HECU soldiers were to either talk indecipherable gibberish, or not speak at all (with exception of pain, death, and idle sounds) as indicated by their voice in many videos, especially from Half-Life Preliminary Findings, the leaked Half-Life 0.52 Alpha, and by the unused "makesquad" sound from Half-Life: Day One. However, the word "Medic" was spoken clearly even in early versions.

Trivia

 * The soldiers in Half-Life: Opposing Force are still coded to fight Black Mesa Personnel. One example of this is before the scene leading to "Friendly Fire." There will be a scientist that comments on the fighting above, and use him.  He will follow you until you reach the electrocuted wires; leave him, then use the radio for an engineer and a grunt to appear.  If they follow you close enough, they will spot the scientist through the gap and open fire, killing him.


 * With the exception of scripted sequences, the grunts and Black Ops seem to be the only ones to reload their weapons.


 * When playing Opposing Force, spawned grunts with the console command "give_monster_human_grunt" will be hostile. The reason for this is because instead of modifying the Vanilla Half-Life grunts to be friendly to the player, Gearbox made a seperate NPC. The console command for spawning friendly grunts is "give_monster_human_grunt_ally."


 * If a soldier is critically wounded, the grunt will yell "MEDIC!" and they will limp; this also applies in Half-Life, even though there is no Medic.


 * In Half-Life, the HECU grunts communicate via radio chatter. How Gordon can hear their transmissions remains uncertain, although the HEV suit may be picking up the radio transmissions. Elsewhere in Opposing Force, the grunts do not use the radio as they use their voices. Oddly, Adrian Shephard does not use his radio at all (if he has any) to talk to other marines. It could be likely that he was not given any radio equipment at the beginning of his mission or perhaps his own radio was broken.


 * The rate of fire of the HECU grunts was upgraded in Half-Life: Source, making their attack more dangerous. The player can easy note this from the shotgun wielding soldier. They fire faster in semi-automatic mode than they do in Half-Life.


 * Based on the conversations amongst the HECU in Half-Life and Opposing Force, not even the HECU Marines themselves knew why they were sent to Black Mesa. Furthermore, according to the diary by Adrian Shephard, rumors remained persistent that they were being trained for a highly secret mission for Black Mesa which hints that someone meticulously planned the demise of the research facility, most likely the G-Man.


 * The standard and shotgun soldier come in two different skin tones, black and white. The beret and demolitions soldiers, however, only come in one skin tone, the beret is white and the demolition is black.

List of appearances

 * Half-Life: Day One
 * Half-Life
 * Half-Life: Uplink
 * Half-Life: Opposing Force
 * Half-Life: Blue Shift
 * Half-Life: Decay
 * Half-Life 2: Raising the Bar
 *  Black Mesa