Half-Life, much like most early first-person shooters, is inextricably linked to horror. In Half-Life’s case, this manifests as an underlying current of psychological horror throughout the series; for the first Half-Life, the horror comes from the unfamiliar and grotesque invading the familiar, as monstrous Xen aliens wreck havoc on the unsuspecting scientists and guards, even mutating them into zombie atrocities, whereas for Half-Life 2 and its episodes, it changes and evolves into a mix of existential dread and the oppressiveness of the dystopia that is the Combine rule.

As such, the games in the series have no shortage of scary moments, even throwing in a few jump scares here and there for good measure. For Halloween, we’re looking at the entire franchise—main games only, so no spin-offs, fan games or even Black Mesa (though it will get a few mentions here and there)—and finding the scariest and spookiest moments in Half-Life games. Beware of terrors and spoilers!

  1. A screenshot of Half-Life. A headcrab zombie walks towards the player as another headcrab chews on the head of a scientist in the corridors of Anomalous Materials labs.
    This might not look too scary now, but it was terrifying at the time (and Black Mesa, the remake, does a wonderful job making it scary again).

    The resonance cascade (Half-Life)

    One of the most ground-breaking things about the original Half-Life at its time was that it didn’t just drop you into the action with a gun and a roomful of enemies from the moment you pressed “New game”. Instead, Half-Life takes its time building its world and atmosphere as the player, in the role of Gordon Freeman, goes on a seemingly ordinary workday at the Black Mesa research facility.

    It’s exactly because of that buildup that the resonance cascade and its immediate after-effects hit so strongly. The moment where shit hits the fan—the resonance cascade itself, as the anti-mass spectrometer floods the test chamber with teleportation energy and starts destroying everything around it—is a great moment of tension and shock, but the real horror comes from leaving the chamber after the disaster and finding the exact same corridors you just walked past completely obliterated, with the scientists and guards that just greeted you and politely pointed out how late you were now sprawled dead across the facility—or worse, horrifying meat puppets for headcrabs.

    For twelve-year-old me, innocently starting to play this shooter without knowing anything about it beforehand, this was a shot of adrenaline straight to the heart and the most terrifying thing I had played so far… and I was hooked for life. It’s more quaint now than spooky, but if you want to reexperience those same thrills and scares, Black Mesa does a wonderful job making the disaster scary again.

  2. A screenshot of Half-Life 2. Beneath the water, the ichthyosaur, a large shark-like alien creature, prepares to eat the player.
    A familiar mouth makes a terrifying cameo in Half-Life 2’s teleportation scene.

    The ichthyosaur jump scare in the teleportation scene (Half-Life 2)

    By comparison with Half-Life’s excellent tension-builder of an opening, Half-Life 2’s starting minutes are much less horror-prone, emphasizing more the downtrodden atmosphere of City 17 rather than throwing scares at you… that is, until the teleportation scene in A Red Letter Day.

    After you make your way through City 17 and finally manage to meet up with Alyx Vance and Doctor Isaac Kleiner, you’re set up to be teleported immediately to Doctor Eli Vance’s laboratory, Black Mesa East. Unfortunately, Doctor Kleiner’s pet headcrab Lamarr just finds your scalp too juicy not to leap at it during the teleportation sequence, throwing you into a sequence of quick teleports between locations, from Black Mesa East to Doctor Breen’s office at the top of the Citadel.

    One of those places is an unsuspecting lake in the middle of God knows where, dropping you in the water for just a brief seconds. As you fall into the dark waters, you suddenly notice an eerily familiar set of eyes staring back at you. Then, an ichthyosaur, one of the Xen creatures seen in Half-Life, races through the water straight at you, its mouth large enough to swallow you whole. You’re teleported back to the exterior of Kleiner’s lab at the very last minute before becoming alien shark food.

    It’s a brief but completely terrifying moment, especially since it’s entirely unexpected—for the past few minutes, Half-Life 2 has been more preoccupied with throwing exposition at you, so the sudden turn helps jolt you awake and is an effective way of keeping you on your toes for the remainder of the game. Unfortunately, it’s the last time we see the ichthyosaur in Half-Life 2 or its sequels, but don’t worry, we’ll see the ichthyosaur again before this list is over.

  3. A screenshot of Half-Life 2: Episode One. The player stares at the elevator at the end of the chapter Lowlife, with a single light still on above the elevator while half a zombie corpse lies beneath, next to a large bloodstain.
    The ominous elevator in Half-Life 2: Episode One right before everything goes to hell.

    The elevator fight in the dark (Half-Life 2: Episode One)

    The Half-Life 2 episodic sequels are perhaps not remembered as quite as scary as Half-Life or even Half-Life 2, generally trading the scares for more pulse-pounding action, but they still have their moments of terror.

    The best one is arguably the elevator scene at the tail end of the chapter Lowlife in Half-Life 2: Episode One. By this point in the game, the developers’ invisible hand has trained you to know how to navigate in the dark through the use of the flashlight—which, as Alyx herself lampshades, is still inexplicably tied to the same stamina meter as running, meaning you can’t quite run and see in the dark at the same time for very long.

    The final test of this skill starts when you come across an old elevator in the middle of a darkened basement. As soon as Alyx pushes the button, its lone light goes out, forcing you back to using the flashlight to find the power supply in the dark. As you navigate the room and fend off zombies in pitch darkness, you manage to turn on the electricity (but not the lights) just as an onslaught of zombies of three different varieties—regular, fast and Zombine—surround you and your companion. You then have to brute force your way through the darkness towards the elevator, which, as usual, takes forever to arrive.

    This sequence builds expertly from the creepiness of stumbling through the dark trying to find the power source to the adrenaline rush of fighting your way through waves of zombies, having to manage not only your ammo but also Alyx’s visibility and your stamina/flashlight power. It helps that it’s accompanied by one of the best of Kelly Bailey’s Episode One soundtrack. If you’re afraid of the dark, it’s downright paralyzing, and the same concept would later be reused in Half-Life: Alyx, though amplified a million times thanks to its use of virtual reality.

  4. A screenshot of Half-Life. An ichthyosaur, a shark-like alien sea creature, swims towards the player with its mouth open in dark, muddy waters.
    This moment took me (and many players) years to get over.

    The ichthyosaurs (Half-Life)

    Half-Life’s roster of creatures perfectly encapsulates the horror vibes of the series; even the lowly headcrab, the first monster the series throws at you, is a nightmarish parasitic creature that turns its prey into a zombie-like horror, still alive but unable to do anything of their own volition but scream in pain and terror.

    With that said, there’s a strong argument to be made that the scariest creature in the entire series is the ichthyosaur. Its introduction is one of the best in the series: you come across it as it catches a scientist, dragging him back into the water with it. You then have to carefully walk and jump through the same catwalk you just saw someone die on, avoiding not only the barnacles hoping for a snack but also falling in the water below, until you reach a scientist that tells you there’s a “tranquilizer gun”—the crossbow—on top of the creature’s cage, dangling precariously over the water. Of course, the moment you catch the weapon and drop into the cage, it falls into the water, leaving you trapped with a ravenous sea monster trying to eat you.

    What makes the ichthyosaur even more effective is just how helpess you are in the water. Almost all of your entire arsenal is useless underwater, leaving you with basically your pea-shooter of a pistol and the aforementioned crossbow (for which ammo is scarce) to fend off the shark-like creatures. Plus, your oxygen supply is limited, meaning you not only have to try and kill a predator with limited weaponry, but also juggle running from it with going up for air before you drown and make the ichthyosaur’s job easier.

    Honestly, while most of the scares of Half-Life faded with time and habituation, I was terrified of the ichthyosaurs for years. Their very limited animation looks fairly silly now, but the sounds are still very effective and the way it essentially flies towards you in the water can still give me shivers every now and again. Of course, this is another bit where Black Mesa’s higher fidelity helps make it scary again. This is one creature I’m almost happy Valve unceremoniously discarded after Half-Life.

  5. A pre-release screenshot of Half-Life: Alyx. A corpse dangles from above with a flashlight attached to it, surrounded by bulbous alien fungi.
    If you haven’t played Half-Life: Alyx yet, trust me: this is even more unsettling in virtual reality. (Credit: Valve)

    When you get the flashlight (Half-Life: Alyx)

    Gabe Newell had been threatening to make Half-Life scary again for years after Half-Life 2 came out, so when we finally got a brand new installment in 2020, that promise was fulfilled… and how. Half-Life: Alyx is possibly the scariest game in the entire franchise, and that’s saying something.

    The fact that you’re essentially in the world thanks to virtual reality helps, of course, but you can tell there was a conscious effort to just up the ante in horror at every turn. Even headcrabs and zombies, the old staples of the series, are scary again, both because you can now actually get the former attached to your face, and for the fact that the graphical fidelity and artistry on display make everything just more gross and lifelike.

    The first moment where Half-Life: Alyx really goes from creepy and tense to pee-your-pants scary is right after you get a flashlight. As you crawl your way through the sewers below City 17’s quarantine sector, you find completely dark places where Russell, your ever-constant companion over the radio, tells you you need a flashlight to proceed.

    You finally find one ominously attached to a corpse that has been engulfed in, for lack of a better term, Xen fungi. Just getting the flashlight from it is tense enough, but it’s what comes right after that becomes really horrifying: as you stumble back through the dark, you suddenly find yourself surrounded by one of the scariest returning monsters from Half-Life 2, the poison headcrabs. If they were already terrifying enough as is in Half-Life 2, in virtual reality they’re even worse, and there’s more than one in the dark for good measure, hissing at you as you try to make your way out.

    Half-Life: Alyx pulls off similar tricks with the dark more than once, all highly effective—one soon after this one as you learn to effectively utilize the flashlight, another much later in the game as an infinite supply of poison headcrabs chase after you inside a hotel—, but you never forget your first. And this isn’t even the scariest part of the game, as we finally get to…

  6. A screenshot of Half-Life: Alyx. Jeff, a mutated creature with a Venus flytrap mouth where a human head used to be, stands in a corridor of the distillery.
    I still have nightmares about that cat Jeff.

    Jeff (Half-Life: Alyx)

    Not to be confused with the other Jeff, Jeff is both the nickname of the scariest creature in Half-Life: Alyx and the name of the eponymous chapter where he appears, which veers from VR first-person shooter into a tense and horrific game of hide-and-seek.

    Deep into the Xen-infested quarantine zone, Alyx finds her way into a distillery where she meets a scavenger by the name of Larry, who introduces her to “Jeff”—a formerly human Combine worker who has been mutated by Xen spores beyond recognition, now being a Venus flytrap-esque monstrous creature who can, and will, kill you in one hit if it finds you. Luckily for you, he can’t see a thing; unluckily, he’s “got an ear like Mozart” and will catch you if he hears you. To complicate matters, the same spores that infected Jeff are everywhere in the area you need to comb through to find three power cells, making you cough loudly if you don’t cover your mouth or use a respirator.

    Jeff (the chapter) is a horror side-trip of the slasher variety, as you try to sneak past Jeff but are consistently thrown into his vicinity by the game’s Machiavellian developers. In a game that is already consistently scarier than its predecessor, this is the horror climax, at least before the endgame goes for a different, more existential horror.

  7. A screenshot of Half-Life 2. The player stares at a bonfire of zombie corpses in the plaza of Ravenholm as Father Grigori makes a speech above it.
    An absolute classic, Ravenholm is where Half-Life 2 turns into a horror game (and physics playground) for one glorious chapter.

    Ravenholm (Half-Life 2)

    If you know anything about Half-Life, then you knew this one was coming.

    Everything about Ravenholm is done expertly, from the Chekov’s gun of walking past its passage earlier—”we don’t go there anymore”—to its Thief-inspired atmosphere. Headcrabs and zombies were already done to death by the time you enter the old mining town, but We Don’t Go to Ravenholm… finds a way to revitalize those old clichés and repackage them into something brand new and intensely scarier than anything that had come before.

    This is also where the fast and poison zombies are introduced, and the introduction of the former is iconic: first glimpsed jumping across rooftops, then suddenly darting at you from the distance as you exit one of the buildings. The fast zombies were terrifying, and their first usage is definitely the best, as more than once you find yourself cornered by the agile beasts, with no way to run. The part where you have to hold your ground as you wait for Father Grigori’s ridiculously slow cart is a particular highlight and perhaps the best use I’ve seen of this particular game mechanic.

    After dozens of playthroughs, Ravenholm is not as scary as it once was, but I still distinctly remember being lost in one of its larger arenas, a seemingly infinite horde of zombies coming after me as I huddled in a corner, low on ammo and with no clue on where to go. It was petrifying and exhilarating and nothing has come close to the sheer terror and adrenaline of it. Plus, if you like some gore in your horror, the plethora of sawblades and other utensils to throw with your brand new gravity gun doesn’t hurt, either.

Do you agree with our list? Anything we might have missed or overlooked? Let us know in the comments below and have a happy Halloween!