Half-Life (series)/Characters

''Warning: Here be heavy spoilers. More is to come.''

Dr. Gordon Freeman


"Age: 27.

Education: PhD in Theoretical Physics, MIT.

Employer and Position: Black Mesa Research Facility, Research Associate.

Assignment: Anomalous Materials Laboratory.

Clearance: Level 3.

Administrative Sponsor: Classified.

Disaster Response Priority: Discretionary.

Beard: Awesome.

Voiced by: ???"

The main hero of the Half-Life series, Gordon Freeman is, at the point where Half-Life begins, a recently graduated scientist who is about half a hour late for an experiment, taking place deep within the Black Mesa Research Facility. If only he had known that it would soon become the least of his worries that day...

Finding himself at the ground zero of a disaster, trapped between a invasion of aggressive creatures from the dimension Xen and a shadowy military force that wants him and his colleagues dead, Freeman manages to battle his way across the facility in the span of two days, staying alive against all odds, aided by his HEV suit and staunch determination. He is eventually teleported to Xen, where he takes on the leader of the aliens, after which he finds himself face to face with the mysterious G-Man, who offers him a job.

His job? Future savior of Earth and figurehead of the Human Resistance. The "One Free Man", and "The Opener of the Way".

"Barney: Good job, Gordon. Throwing that switch and all? I can see your MIT education really pays for itself."
 * Asskicking Equals Authority: By the time of Half Life 2, he doesn't have any definitive rank in the rebellion, but he pretty much commands any rebel squads he comes across, who are all too willing to Zerg Rush a position if he so much as looks at it, all because he's good at killing things.
 * Badass:
 * Badass Normal
 * Badass Bookworm: His doctoral thesis is ludicrously titled "Observation of Einstein-Podolsky-Rosen Entanglement on Supraquantum Structures by Induction Through Nonlinear Transuranic Crystal of Extremely Long Wavelength (ELW) Pulse from Mode-Locked Source Array". In laymen's terms... looking at teleportation effects on crystals when you fire lasers at them.
 * Badass Beard
 * Badass Biker: His original character model was a long bearded, middle-aged guy with a flat-top haircut. This incarnation received "Ivan the Spacebiker" as its nickname.
 * Did You Just Kill The Nihilanth
 * Dude, Where's My Respect?: Averted. His reputation actually seems to do more work than him. He's pretty badass, but it was his reputation, not his actions, that caused most of the rebellion on Earth against the Combine.
 * The Hero
 * Implacable Man: Gordon Freeman didn't really mean to save the world by slaughtering hundreds of soldiers and aliens at Black Mesa. They were just in the way of the exit.
 * Since he says absolutely nothing, ever, we don't really know whether or not he did.
 * Informed Ability: Gordon is a theoretical physicist, but the most technically complex things he does in the games are plug machinery in and solve rudimentary physics puzzles.
 * Lampshaded by Barney in Half-Life 2.


 * Lightning Bruiser: He can take quite a bit of punishment, thanks to the suit, but can also run at ridiculous speeds and carry more firepower than the 82nd Airborne.
 * Nice Job Breaking It, Hero: The entire Resonance Cascade incident, duh!
 * Well, all Gordon did was push the crystal in. But still, all hell broke loose on his watch.
 * Right Man in The Wrong Place: The Trope Namer, as described by the G-Man.
 * Silent Protagonist: The whole time. Exception would be when he was breathing during the Resonance Cascade incident, if that counts.
 * In Half-Life 2, Gordon also utters mild grunts of pain sometimes when he's on fire or falls from leg shattering heights.
 * Power Armor: His HEV Suit
 * One-Man Army: While his suit is a big part of it (it gives him about 4 times as much health as a regular soldier when fully charged, can automatically reload his holstered weapons, and applies morphine and other assistance to keep him going at full strength even when badly wounded), it is still pretty amazing considering he is just a scientist.
 * The best example is probably at the end of Episode 2.
 * Specs of Awesome
 * Weapon of Choice: His trademark weapon is a red crowbar he found in a tool kit at black mesa.
 * Alternatively, he's also depicted wielding a pump-action shotgun.

Barney Calhoun


"Age: Unknown.

Education: 2 years Martinson College, Undecided Major.

Employer and Position: Black Mesa Research Facility, Security Guard.

Clearance: Level 3.

Disaster Response Priorities: Preservation of research equipment and materials, welfare of personnel, and personal safety."

"Voice Actor: Mike Shapiro (Half-Life 2 and Episode One)"

The player character in Blue Shift, Barney Calhoun was a security guard at Black Mesa, and arrived to his duties at the same time as Gordon. Unlike Gordon and Adrian, he was the only Half-Life 1 player not to have an HEV Suit, and the only main character to escape from Black Mesa on his own, along with a few scientists.

In Half-Life 2, Barney, posing as a Combine Civil Protection security guard, saves Gordon from heading to Nova Prospekt. Helps Gordon in the Resistance movement in City 17, and for Episode One, helps some of the residents evacuate. Last seen boarding a train outbound from City 17 by the end of Episode One with the help of Gordon and Alyx, his whereabouts are unknown in Episode Two.

"Barney: And if you see Doctor Breen tell him I said "FUCK YOU!""
 * Ascended Extra: From being a stock security guard in Half Life to the star of Blue Shift to a major character in Half Life 2.
 * Badass Normal: Went through Blue Shift with only security guard equipment.
 * The Lancer: Fills the gap for Alyx in Half-Life 2 during the chapter Follow Freeman!
 * Nice Guy
 * One-Man Army: In "Blue Shift"
 * Precision F-Strike: Gives one at the end of the chapter noted above.


 * Of course, it's censored by Dog closing the entrance into the Citadel that you just entered, but the dialog is intact in the game files.
 * Put On a Bus: More accurately, the second-to-last train to leave City 17 at the end Episode One.
 * Reverse Mole - Works within the Civil Protection and uses it as a means to help civilians escape from the city
 * Rebel Leader: He seems to be the rebels de facto field commander, behind in rank only to Eli and maybe Gordon.
 * Took a Level In Badass: Barney handles himself well in Blue Shift (even surviving through Xen, for one), but when we meet up with him in the second game, he's one of the leaders of the Resistance, their mole in Civil Protection, and once the revolution hits the streets, a competent field commander.

Corporal Adrian Shephard


"Age: 22.

Training: United States Marine Corps, Special Forces.

Assignment: Hazardous Environment Combat Unit, Santiago, Arizona.

Mission: Classified."

The player character in Opposing Force, Adrian Shephard was one of the men in his unit assigned to Black Mesa to do a full containment, cleaning out the witnesses, and finding Gordon Freeman. However, his transport was ambushed and shot down before he was given his mission, which leads him to work together with Black Mesa's scientists and security guards despite them becoming increasingly distrustful of him as the game progresses. In some of his attempts to escape and regroup with any members of his team, the G-Man both helped and hindered him along the way.

He was ultimately detained by the G-Man in Another Dimension at the end of Opposing Force, now pending further evaluation.


 * Badass Normal: Well, he is a highly trained marine with the best equipment that his unit can provide, but he still is way better at fighting than the other soldiers.
 * The Faceless: Has only two character art pictures of him, both with his gas mask on. His multiplayer image is just a generic HECU soldier.
 * Fate Worse Than Death: We don't know much about his detainment, but it's probably like this.
 * Fingerless Gloves: Yet he wears a gas mask.
 * Long Bus Trip: Despite the facts that Opposing Force ends with Shephard in in a state from which he could easily be brought back, and Gabe Newell himself have stated that Valve is planning to "bring him back one of these days", no mentioning of him has been made in any of the Half-Life sequels.
 * One-Man Army
 * You Remind Me of X: G-Man uses variant 1 towards Shephard, and mentions his ability to survive against all odds as the main reason. G-Man also mentions that this why he saved Shepard's life and argued against his employers' wishes to kill him.

Alyx Vance


"Voice Actor: Merle Dandridge (Half-Life 2, Episodes One and Two)"

The heroine of Half-Life 2, Alyx Vance helped Gordon Freeman time and again in his work with the Resistance. She also follows Gordon the whole way throughout Episodes One and Two.


 * Action Girl
 * Badass Normal
 * Badass in Distress:
 * Fingerless Gloves
 * The Lancer: To Gordon for the Episodes.
 * Master of Unlocking
 * Made of Iron: It takes an ungodly amount of punishment to kill her, and unlike Freeman and Shepard, there is not in-game justification for it.
 * Nerds Are Sexy: She's very knowledgeable about science and mechanics. Most of DOG is her work.
 * Precision F-Strike: She responds to  with "Enough of your bullshit!".

Dr. Eli Vance


"Voice Actor: Robert Guilliame (Half-Life 2, Episodes One and Two)"

A major character in Half-Life 2, Eli Vance is one of the survivors of the Resonance Cascade incident, a lead member of the Resistance, and Alyx's father. Also known to be a Harvard graduate.

""When he came in, I knew I should have aborted that damn test. But I didn't. The whole world went to hell that day.""
 * Artificial Limb: Eli apparently lost his left leg during an incident involving a bullsquid. He has a makeshift prosthetic now.
 * Distressed Dude: One of the major goals driving the plot is Alyx's quest to rescue her father, twice.
 * Hey, It's That Voice!: Has Rafiki's and Benson's voices
 * I See Them, Too: So far, he has been the only character who has acknowledged G-Man's existence to Gordon.
 * I Want Grandkids: Hey, you can't blame him, considering the Combine's anti-reproduction suppression field in the past years.
 * My God, What Have I Done?: The personal cutscene between Gordon and him in Episode Two pretty much made him admit
 * My God, What Have I Done?: The personal cutscene between Gordon and him in Episode Two pretty much made him admit


 * Rebel Leader
 * Retcon: Remember that scientist in Half-Life 1 that sent you up for help after the Resonance Cascade and opened the door for you? That's Eli.

Dog
A walking junkpile that moves like a robotic gorilla, but has an effective mindset of a dog, hence his name. Fiercely loyal to and protective of Alyx, and her friends by extension.


 * Badass Automaton:
 * Berserk Button: Alyx in danger.
 * Big Friendly Dog: You play catch with him as part of Alyx's training regime for the gravity gun.
 * The Big Guy
 * Curb Stomp Battle: Him versus any Combine forces short of a Strider. His favored method is to pick up ground vehicles and throw them at the enemy.
 * David Versus Goliath:
 * Robot Buddy
 * What a Piece of Junk!: Consider him a junky old robot at your own peril if you're a Combine. He will thrash you.

Dr. Isaac Kleiner
"Voice Actor: Harry S. Robins (Half-Life 2, Episodes One and Two)"

A major character in Half-Life 2, Dr. Kleiner was the man who recommended Gordon Freeman to Black Mesa Research Facility's Civilian Recruitment Division. Also a survivor of the Resonance Cascade incident at Black Mesa.


 * Absent-Minded Professor
 * Adorkable
 * Fluffy Tamer: He keeps a 'de-beaked' headcrab as a pet. Her name is Lamarr.
 * Noodle Incident: It has to do something with the cat and the teleporter in his lab. Barney mentions the cat twice.
 * The Smart Guy

Dr. Judith Mossman
"Voice Actor: Michelle Forbes (Half-Life 2, Episode One)"

The other scientist at Black Mesa East, and is somewhat distrustful of Alyx. Also played traitor for Wallace Breen, but after coming back to her senses, she eventually saves Gordon, Alyx, and Eli from him near the end of Half-Life 2. Was last seen with Resistance members tracking down the Borealis, and got ambushed from the Combine before she could finish her message. She is still alive, whereabouts unknown. Her message was found by Gordon and Alyx, who were pursued by the Combine [for the entirety of Episodes One and Two] while delivering it to the scientists in White Forest Base. She will be most likely seen again in Episode Three.


 * Jerkass
 * Jerkass

Dr. Arne Magnusson
The manager of White Forest Base. Has a very distrustful relationship with Isaac Kleiner (well, they fought between each other for grant money). Later revealed to be the owner of a certain microwave casserole in the lounge of the Sector C Personnel Facilities in Black Mesa.


 * Brick Joke - Remember the casserole you had the option to blow up in the beginning of the first game? According to canon, that just so happened to be Arne's casserole, and Gordon did in fact blow it up, something Arne still hasn't forgiven.
 * Insufferable Genius
 * Jerkass - Specifically created to be this to contrast with Eli and Kleiner

Father Grigori
"Voice Actor: Jim French (Half-Life 2)"

Very little is known about him other than that he's a Russian Orthodox preacher of questionable sanity who has taken it upon himself to clear his "flock" from Ravenholm.


 * Badass
 * Badass Preacher
 * Badass Normal
 * Badass Beard
 * Bald of Awesome
 * Crazy Survivalist: Grigori's the nice kind.
 * Meaningful Name: "Grigori" is a term in Biblical apocrypha for a group angels tasked with watching over humanity as well as the name of another famous Russian preacher who was very hard to kill
 * Sanity Slippage: He's obviously insane, although it's implied that he was driven insane by the whole headcrab infestation in Ravenholm.
 * Weapon of Choice: A .357 caliber lever action rifle he refers to as "Annabelle".

Colonel Odessa Cubbage
"Voice Actor: John Patrick Lowrie (Half-Life 2)"

A somewhat suspicious and supposedly British Resistance colonel, leading the New Little Odessa base along the coast. He only appears briefly in the 7th chapter of Half-Life 2, granting Gordon a rocket launcher.


 * Call Back: After playing out his minor role i Half-Life 2, he disappears from the plot, and there is no mention of him again. Then, late in Episode One, three independent mentions suddenly turns up concerning him, first Alyx sarcastically claiming he is her father, then two rebels coming to the conclusion that he is an aidiot, and finally a rebel who reveals that he had taken the credit for Gordon's work, and who turns out to be an admirer of him.
 * Cower Power: When the base he has responsibility to lead comes under an attack threatening its vety exixtence, no less, Cubbage sends Freeman to dispatch the gunship, while he safely hides to send a warning to another base, that mysteriously never reaches its destination.
 * Fake Brit
 * Complete with fake mustache.
 * Miles Gloriosus: While there is no explicit mentions of his great military exploits, he does by no means seem like someone deserving a colonel title.
 * Better yet, a passing commend in Episode 1 reveals that he took the credit for shooting down aforementioned gunship.
 * Mysterious Past: The Prima Guide to Half-Life 2 states that virtually nothing is known of Cubbage's past, his name may even be taken from the outpost, the only thing sure is his cowardice.
 * If Gordon uses the Combine binoculars overlooking the New Little Odessa, he can be seen talking to the G-Man.
 * Rebel Leader: Although how significant he is doubtable.
 * Small Name, Big Ego: It is staggeringly clear that he believes himself to be one of the great heroes of La Résistance, although he appears to be the only one with this view, apart from one rebel in Episode One speaking somewhat highly of him.

Griggs and Sheckley
A pair of resistance members in an underground base, they help Freeman defend the base against an army of Antlions to protect the Vortigaunts while they heal Alyx.


 * Badass Normal: Sort of. They are just normal resistance members, but they perform surprisingly well against the army of antlions.
 * Deadpan Snarker
 * Those Two Guys
 * Properly Paranoid

Dr. Wallace Breen


"Voice Actor: Robert Culp (Half-Life 2, cameo in Episode One)"

Breen is the earlier head of The Black Mesa Research Facility, and was unnamed and unseen in the first game, where he is merely referred to as "The administrator". In Half-Life 2, he is the main antagonist and the Combine's puppet ruler of Earth, a position he got after selling out mankind to them.

"Dr. Breen: "Having both of you in my keeping ensures I can dictate the terms of any bargain I care to make with the Combine.""
 * Beard of Evil
 * Corrupt Corporate Executive: He was the administrator of Black Mesa before becoming the Combine governor of the Earth, and pushed for the risky analysis that eventually led to the disaster in the first game.
 * The Ghost: In the first game, he's just referred to as "The Administrator" a couple of times.
 * Hypocrite: In his Breencasts, he criticizes people who call the Combine by their name preferring "Our Benefactors" and "Universal Union", when you meet him in person, he's all
 * Hypocrite: In his Breencasts, he criticizes people who call the Combine by their name preferring "Our Benefactors" and "Universal Union", when you meet him in person, he's all


 * Misanthrope Supreme: His motivations are a wee bit unclear. He did convince The Combine to enslave rather than exterminate humanity (and was afterwards named Administrator of Earth), but whether he did so for personal power, or because he really cared about humanity is left unclear.
 * The Quisling
 * Smug Snake: Things escalate beyond his control rather quickly.
 * Villainous Breakdown: He becomes increasingly impatient and childish as Gordon Freeman kills off his soldiers and starts a rebellion.
 * Well-Intentioned Extremist: Judging by the events of the Seven Hour War, he managed to stave off extinction. It was either Death or A Fate Worse Than Death. He chose the latter. Breen might honestly believe that the Combine will elevate humanity to the next level, though he has turned a blind eye to Transhuman Treachery by the Combine.
 * Wicked Cultured: He shows a mild example of Sesquipedalian Loquaciousness, and makes reference to advanced physics notions several times, but we're not sure exactly what his Morally-Ambiguous Doctorate is actually in.

The G-Man


"Voice Actor: Mike Shapiro (Half-Life 1 and 2, Episodes One and Two)"

A strange character, looking like a blend between a government worker and a businessman, who apparently has some limited control over space and time. All we know is that he's been observing the events of the entire Half-Life series. And that he is possibly not entirely human. He apparently answers to some higher authority which he simply refers to as his "employers". He has, however, on a couple of occasions hinted that he does not necessarily obey these "employers".


 * Ambiguously Evil: On one hand, his chessmaster antics, creepy dialogue, and mysterious powers make him easy to see as a villain of some sort. Plus, the Vortigaunts seem to oppose him. On the other hand, we know absolutely nothing about who he actually is and what his motivations are, and he seems to oppose the Combine, who actually are villains, and he has saved Freeman and Shephard's lives on several occasions.
 * AcCENT Upon the Wrong SylLABle
 * Angel Unaware
 * Blue and Orange Morality: For whom does he play? No one knows but him.
 * Creepy Monotone: He rarely shows emotion.
 * The Chessmaster: Although no one even knows what he is trying to accomplish.
 * Invisible to Normals: He can apparently choose which persons are able to see him, and it is hinted that he also has some power over if they remember him or not afterwards.
 * Manipulative Bastard: From locking out Gordon and Adrian from certain doors, to shoving them in deep-freeze, yeah.
 * No Name Given: "G-Man" comes from the name of his character model, and as such is not his actual name.
 * Offscreen Teleportation
 * Humanoid Abomination: Maybe. Standing still, he looks human. When he moves - and where he appears - tells you that he cannot be.
 * The Spook
 * Time Master: He seems to be able to stop time at the very least.
 * Uncanny Valley: Invoked intentionally. Word of God states that he's to hint at something trying hard to look human and failing.
 * The Wonka

The Vortigaunts


A race of three armed mystics and former slaves from the borderworld of Xen, with mystical powers such as healing, shooting electricity, and even stopping the G-Man.

""What seems to you a sacrifice is merely, to us, an oscillation. We do not fear the interval of darkness.""
 * Badass Grandpa: Think an entire race of Yodas. It's exactly as awesome as it sounds.
 * In fact an Easter Egg in Half-Life 2 leads you to one of them who lives like a Hermit Guru, known in Fandom as the All-Knowing Vortigaunt.
 * Death Is Cheap / Brain Uploading: Apparently, via the "Vortessence":


 * Fate Worse Than Death: The All-Knowing Vortigaunt states that Freeman did the enslaved Vortigaunts a favor by killing them.
 * Hive Mind: Or at least connected somehow on a metaphysical level by the Vortessence.
 * Shock and Awe
 * Slave Mooks: In the first game, but then Gordon Freeman freed them from control of their alien masters.
 * Slave Race: In the first game.
 * Starfish Aliens: They have at least four eyes. That seem to all be the same eye. Also, they have three arms, lightning powers, and some sort of Hive Mind (that may or may not overlap with the very (vort)essence of the universe).
 * Starfish Language: Vortigese and the related "flux-shifting" ranges from a 'normal' spoken language to telepathy to a language where two vortigaunts have to talk at the same time to properly communicate.
 * Took a Level In Badass: In the first game, they were disposable mooks whose main strategy was suicidally charging their electric blasts against Freeman (and the marines) then running away if they actually managed to hit (whoever they were attacking usually shot them first unless they attacked in groups, and they often did). in the second game, after they come on your side, they have about 80 % more health and their attack charges faster, as well as being about 50 % stronger. You even meet 3 particularly Badass ones who are able to fend off an entire army of antlions by themselves.

The Combine, a.k.a. The Universal Union
A powerful trans-dimensional alien empire, they conquered the earth and are the main antagonists in Half Life 2 and its episodes, as well as the whole series, as the Nihilanth was enslaved by them. They have a large military consisting of modified humans and human vehicles (such as APC's and attack helicopters), and "Synths", aliens who have been modified and outfitted with cyborg attachments and pulse weaponry.


 * Artificial Brilliance: None of the Combine forces are stupid. The Overwatch soldiers will flank, throw grenades, and run to cover when reloading, the Hunters will use splash damage, flank, and lay down suppression fire, and the Gunships will wildly strafe while firing, and will even shoot down your missiles in mid-air. Foot-soldiers, however, do not have a high amount of hit points, and will usually get killed by the player before their strategies can kick in.
 * Authority Equals Asskicking: The Combine Advisors are the top tier in the Combine hierarchy, or very close to it; they have the authority to subsume any Combine forces they need, and sacrifice them without a second thought. While they resemble blind limbless grubs the size of baby elephants, they have powerful telekinetic and telepathic abilities, and are able to completely immobilize and control anyone around them, as well as levitate themselves for transport.
 * Big Bad: Basically of the entire series.
 * Boss in Mook Clothing: The Striders, which are fought once in each game/episode following Half Life 2, represent a different boss trope every time they are fought.
 * The first battle with 4 striders in the middle of the uprising in City 17, is a Wolfpack Boss. The striders themselves are strong, with powerful cannons and armor that can withstand 7 missiles on normal mode, but together they are an absolute pain in the ass.
 * The single strider encountered at the end of Episode One is more of a straight up Final Boss. Mostly because, one, you have to dodge your way through the scenery to find a rocket launcher, the only weapon that will damage them, two, it's noticeably more accurate than a normal strider, and the three, the map you fight it in is specially designed to fight it in.
 * The final battle at the end of Episode Two is sort of a combo between Wolfpack Boss and Flunky Boss, mixed with a little bit of Sequential Boss. About a dozen striders will come and attack the rebel base in waves, each one supported by about 2-3 Hunters. Sound hard? Well, it just so happens you're given full ammo on all your guns, a new special weapon that can one hit kill the striders, and a car that can kill Hunters in one hit if you ram them at high enough speeds. The fight is still hard, though most of the danger comes from the Hunters, as the striders only shoot at you with their anti-personnel pulse gun and focus their Giant blue laser on destroying the rebel troop clusters and buildings.
 * Elite Mooks: The Combine Elites
 * Fake Ultimate Mook: The Combine Overwatch may look big and scary, but the untrained rag tag rebels are actually better shots (strangely this only applies to SMG's, rebels and combine soldiers are on par in accuracy with the other weapons). The Overwatch soldiers are actually more effective in combat though because of their heavy weapons and health.
 * Gas Mask Mooks: Justified, in that Overwatch Transhuman troops might in use on other, non-human-habitable planets.
 * Apparently the Civil Protection officers just wear them because it looks intimidating.
 * Humans Are Special: Averted; it's clear that they don't give two shits about Earth or the humans, considering the token force they've left to occupy it and the state of the planet after they're done draining it for resources. They've conquered thousands of species, the humans are just one more to them.
 * Insectoid Aliens: The land Synths look like insectoids, while aircraft Synths look more like cetaceans or crustaceans. Made of metal. With guns.
 * Load-Bearing Boss: A collective, in-story version. For all the Combine's cruelty, they at least did manage to keep the massive Antlion infestations in check and keep headcrabs out of their cities. But then Gordon Freeman blew up Nova Prospekt, destroyed their defensive network of machine gun bunkers and 'thumpers' on the coast (thereby letting the Antlions into Nova Prospekt), slaughtered hundreds of soldiers and Synths, started a worldwide rebellion, and blew up the Citadel. All these things caused the Combine to lost control over City 17, resulting in a massive invasion by the nearby Antlion colonies and an infestation of headcrab zombies. By the time Episode One begins, the entire region is caught in a four way struggle between the hundreds of zombies pouring in, the retreating Combine Overwatch forces, the still-persistent rebellion, and what must be thousands of Antlions led by the Antlion Guards.
 * Mini Boss: Gunships and Striders.
 * Organic Technology: The Synth units.
 * Planet Looters: It's very clear that the Combine have no long-term plans for Earth. They're visibly just taking every resource they can use (including the oceans, atmosphere, and some population) and shipping it off-world.
 * Slave Mooks: An entire army of them, most of the Combine soldiers you fight throughout Half Life 2 and its episodes are actually cybernetically modified and enslaved transhumans. Also, the "Striders" "Gunships" "Hunters" "Dropships" and "Synth Scanners" you see in-game are all enslaved aliens or biomachines. It's implied that there are millions of enslaved species.
 * Sufficiently Advanced Aliens / The Juggernaut: They curb-stomped the combined military might of every country on Earth in just seven hours. It took Dr. Breen to convince them not to exterminate every single human and settle for enslaving us instead.
 * Police Brutality: Civil Protection, some of their terror-mongering acts include beating people for no reason, shooting people after they surrender, and lining up innocent people on walls and using them for target practice, in true Nazi-Gestapo-meets-Soviet-KGB style. Think of them as a world-wide example of the Stanford Prison Experiment.
 * Sociopathic Soldier: Surprisingly, not the Overwatch. They're just brainwashed slaves. No, the real sociopaths here are in Civil Protection, mentioned above in Police Brutality; the corps consists of humans who joined the The Combine's forces willingly, for perks like extra rations and sexual privileges. They appear to be somewhere between SWAT police and low-ranking soldiers. Their tasks are basically to instill fear in every citizen, and to brutally crack down on small resistance pockets. Their technology is notably a bit more primitive, as well. Where the Overwatch and Airwatch use Striders, Gunships and energy weapons, CP units make due with APCs, patrol helicopters and sub-machineguns.
 * Starfish Aliens: The creatures running the whole thing, called "Advisors", resemble rhino-sized brain-sucking grubs with no eyes, arms, legs or face. The developers deliberately wanted to invoke the image of a species that passed its Singularity a very long time ago. They rely on mechanical arms and eyes for manipulation, and anti-gravity packs for movement. Well, those and their near-unstoppable telekinetic and telepathic abilities.
 * Kind of hard to tell since the Synths are obviously modified, but the Overwatch soldiers show that even the Combine's modified forces vaguely resemble what they looked like prior to being enslaved. In this case, many of their aliens are most definitely weird, particularly the Gunships.
 * Suicidal Overconfidence: Part of their official policy. Any Overwatch soldier who fails and lives to report about it will receive "permanent off-world assignment". Their destination is likely not pleasant.

Race X
A mysterious alien race from the other dimension, they only appear in Opposing Force, where their invasion is repelled by Adrian Shepard and his men, and is finally ended when the US government nukes Black Mesa. Their main soldiers are "Shock Troopers", but they also have creatures such as a giant worm that shoots lasers and a small, fast poultry-like creature that attacks with scythe-like claws.


 * Big Bad Ensemble: Opposing Force reveals that US Black Operations and Race X (led by the Gene Worm) were also largely responsible for the events of the first game. The HECU, on the other hand, were just doing whatever they needed to do to stop the invasion and survive the Black Ops onslaught.
 * Eye Scream: The way to defeat the Gene Worm.
 * Made of Iron: The Shock Troopers take about twenty MP5 shots to kill, or just three Desert Eagle shots. That's twice as much as the average human soldier.
 * Planet Looters
 * Shock and Awe: The aptly named "Shock Troopers", who carry a weapon called a "Shock Roach", a parasitic bug that shoots deadly electricity when squeezed. Also, the Voltigores, large creatures which shoots powerful bolts of purple electricity.
 * Shrouded in Myth: You don't learn much about them other than that they want to take Earth's resources and that they are hostile to Xenian and US Military forces.
 * Starfish Aliens: Especially the Gene Worm, a very large creature that shoots acid, and can teleport in "Shock Troopers". The manual for the game implies that the gene worm is several miles long and can suck the resources out of a planet, and that the creature you fight at the end of Opposing Force is just its head.

The Nihilanth
The ruler of the Xen aliens and the main antagonist of The first Half Life (and by extension, Blue Shift and part of Opposing Force). His race was under severe threat from the Combine. To escape them, he used the Resonance Cascade to launch an invasion of Earth, and despite the Black Mesa's scientists' best efforts to plug the rift between the dimensions, he was able to use his psychic powers to force it to stay open. His forces had success with pushing back the HECU, but his invasion was ended when the Black Ops nuked Black Mesa and Gordon Freeman traveled to Xen and killed him, finally closing the hole in the dimensions. He enslaved the Vortigaunts prior to the events of Half Life. "Nihilanth: ...THE LAAAAAAST. I AM THE LAAAAAAST. I AM..."
 * Authority Equals Asskicking: Just like the Combine Advisors, he leads a large army and has very powerful telekinetic powers, which include the ability to teleport himself and others, telepathy, the ability to shoot extremely powerful balls of lightning which pretty much kill you instantly, and levitation. His commanders and possible relatives, the "Alien Controllers", also possess these abilities, but to much less powerful degrees.
 * Anticlimax Boss: It really depends on how much ammo you have, but if a couple glitches are exploited and the right weapons are used, it is possible to easily kill him in three or four minutes. The Gluon Gun in particular is capable of absolutely destroying him.
 * Body Horror
 * Evil Sounds Deep
 * Final Boss
 * Flunky Boss: One of the more annoying parts about the fight with him. He'll launch a green orb that either teleports you to another room or spawns some vortigaunts or Alien controllers in his chamber. The second option isn't so bad, since he only spawns a few at a time, but him teleporting you to another room is very frustrating. In one instance, he'll teleport you to a room with a Gargantua, forcing you to have a boss fight in the middle of another boss fight.
 * Interim Villain: Strange inversion; he's only the villain for the first game, but his defeat leads to the Combine finding Earth.
 * King Mook: He's basically a much, much, much, much more powerful Alien Controller with a teleport attack.
 * Load-Bearing Boss: Killing causes him to explode, which knocks Gordon out.
 * Large and In Charge: The largest alien ever encountered in the series in terms of pure size. Even bigger than the three story tall tentacle monsters.
 * Meaningful Name: Word of God says Nihilanth implies Nihilism. The -anth suffix relates to the flower-shape of this head.
 * Pivotal Boss
 * Puzzle Boss / Damage Sponge Boss: To actually damage him, you need to find out that he is using the crystals to regenerate his forcefield and destroy the crystals. After that, his forcefield wont regenerate, and he can be killed, but it takes quite a bit of damage.
 * Say My Name: "FREEEEEEEEEEEMAAAAAAAN!"
 * Single Specimen Species: Justified, since he's...
 * Last of His Kind Said by the Nihilanth himself just before Gordon enters his chamber:


 * Shock and Awe: He can launch a series of powerful balls of lightning that kill you almost instantly.
 * Turns Red: Inverted. Throughout the battle with him, he will become progressively weaker as he gets injured until he finally just starts firing one ball of lightning at a time at you, as opposed to the dozens he fired before.

The HECU (Hazardous Environment Combat Unit)
The special forces unit who was sent to Black Mesa to clear up the aliens, it is soon discovered that they are also under orders to silence all the Black Mesa personnel...with bullets. They end up having to pull out, leaving behind dozens of their own troops in the process, while the Black Ops took over the operation.


 * Artificial Brilliance: They were praised as being the first tactically intellegent enemies in video games.
 * Badass Army
 * Band of Brothers: Subverted and played straight. Many soldiers throughout Opposing Force are shown to care for their squad mates, but the same can not be said for many other members of the unit, particularly the commanders, who abandon several dozen soldiers in their attempt to escape from Black Mesa in blatant violation of the "Never Leave a Man Behind" policy. In fact, two of the soldiers refuse to turn Gordon over to their bosses because they don't want to see him alive after he'd killed so many of their compatriots.
 * Cavalry Betrayal: You rather quickly find out that they are not at Black Mesa to help the employees and especially not Gordon.
 * Drill Sergeant Nasty: The Opposing Force training level has one guide you through, quoting Full Metal Jacket the whole way.
 * Faceless Goons: The shotgun wielding ones wear balaclavas. However...
 * Gas Mask Mooks: Most of them wear chemical warfare gear, such as gas masks, although the officers wear berets.
 * Firey Coverup: Their mission.
 * Moral Myopia
 * Retcon: Originally, they were only called "soldiers" or "the military". They received their current name in Opposing Force. In the original Half Life, their helicopters even had a US Army logo on them.
 * Given this, and some other facts (HECU grunts are recognized as marines, land vehicles have Army markings, the F16 is a plane used by the USAF) some fans have theorized that HECU is a multi-branch effort, like SOCOM in real life.
 * Sociopathic Soldier: A few of them seem to take joy in killing innocent scientists.
 * Punch Clock Villain: Most of them, however, just do what their commanders tell them too, as evidenced by various lines throughout Half Life and Opposing Force.
 * More Dakka: Many of their weapons, such as the M249 and Flash missile launcher. Hell, even their standard issue sub machine gun has a 50 round magazine.
 * Radio Voice: They spoke this way, and it sounded extremely robotic. May have something to do with most of their Enemy Chatter being Mad Libs Dialogue.
 * Semper Fi
 * The Engineer: He gets introduced in Opposing Force. While engineers are meant to fix vehicles, the engineer in Opposing Force is more useful for just opening locked doors with his blow torch and fighting with his Desert Eagle.
 * The Medic: Another class introduced in Opposing Force. While he isn't very effective with his Glock 17 handgun, he is the only thing in the game that can heal your teammates.
 * The Big Guy: Yet another class introduced in Opposing Force is a tall, muscular soldier toting an M249.
 * You All Look Familiar: They had exactly four models, which just changed the head: the (always caucasian) officer who wore a beret, the normal mook who wore a gas mask, the shotgun using soldier who wore a balaclava and goggles, and the grenade launcher using African-American soldier who wore no hat or mask, but smoked a cigarette. The latter was changed to simply being an African-American version of the commander with a mustache in the HD pack.
 * You Have Outlived Your Usefulness: They didn't think that their bosses would stop at killing the scientists because they saw too much, did they?

The Black Ops
A very shadowy unit sent to Black Mesa after the HECU failed their tasks, the Black Ops are there to remove everything in the facility, including the dozens of HECU stragglers left behind. Their purpose is only explained in Opposing Force.


 * Badass Army: See Elite Mooks. Also, the fact that they never make noise is pretty impressive when they're being shot constantly.
 * Black Helicopter: They use black AH-64 Apache attack helicopters
 * Elite Mooks: In addition to being completely silent, the male black ops they use powerful hand to hand moves at close range, run much faster than the marines, and have a little more health. The female black ops on the other hand prefer to flip and jump around wildly while pelting the player with pistol fire and kung-fu kicks.
 * Faceless Goons: They all wear balaclavas, and the female black ops also wear night vision goggles.
 * Highly-Visible Ninja
 * Fan Service: The Female Black Ops had a very exaggerated breast bounce when they walked, never mind they wear absolutely skin-tight overalls.
 * Ninja: They are ninjas in all but name, complete with silent, fast movement and using karate kicks and punches at close range. They even look just like them
 * Radio Voice: Averted, even though you only hear them speak once (they're completely silent the rest of the time).
 * Sociopathic Soldier: Unlike the HECU, played completely straight.
 * Van in Black: Well, M35 truck in black.
 * Van in Black: Well, M35 truck in black.