Louis: We made it... I can't believe we made it!
A Co-Op Multiplayer First-Person Shooter developed by Valve and proclaimed by its advertising as "the Zombie Apocalypse you can play with your friends." Left 4 Dead reduces the zombie genre to its absolute basics: You are one of a Ragtag Quartet of Misfits caught in the middle of the outbreak of a deadly virus that's turning people into bloodthirsty mutants. Your objective is to make your way from safehouse to safehouse through an area infested with these murderous creatures, and finally reach a pickup point from which to summon the cavalry to spirit you to safety.
Of course, this won't be easy. You have your three pals, and due to the Drop-In Drop-Out Multiplayer nature of the game, there are fairly-competent AI bots standing by for when you don't have allied players. And don't worry about them hogging the kills: there are plenty of infected to go around. There could be a herd of thirty zombies, or just one extremely powerful mutant zombie, waiting around the next corner. The game's "AI Director" is watching your progress and planning your next sudden encounter; play the same campaign five times and each time will be a different experience. The director drops health packs less often than you need it and spawns a horde of zombies whenever he's bored. Which is all the time.
Almost as addictive as the Campaign mode is Versus mode, in which eight players, trading off between rounds, control either the Survivors or the dangerous Special infected: the long-tongued Smoker, the lightning-quick Hunter, the nauseous (and explosive) Boomer, and the Tank. In the sequel, the Self-explanatory Charger, the acid-puking Spitter, and the body-clinging Jockey are also available to play as. (There's another type of Special infected -- the Witch, who doesn't react well to flashlights and loud noise -- but like the Horde she's not actually a playable character.) The goal of Versus is nominally to make it to the next safe room, but nine times out of ten, you won't. The goal is to make it farther than the other team.
The expansion pack takes it further with the ironically-titled Survival Mode: "survival" is pretty much the last thing you'll be doing. The question is how long you and your friends can hold out against an all-out Infected onslaught before you all die.
The game also received massive critical acclaim for its use of emergent narrative -- the parts of the story that they don't tell you, and the interactions of the survivors.
Due to the number of examples, they have been divided into categories.
Followed by Left 4 Dead 2.
General Media Tropes
- Abandoned Hospital: Mercy Hospital in the No Mercy campaign.
- Abandoned Warehouse: Nearly every campaign features one.
- Absurdly Spacious Sewer: At least two of the campaigns feature sewers that are big enough to accommodate whole mobs of zombies for the players to fight off.
- The Aloner: Any Survivor can become this if all but one die. The sequel even adds a mode that invokes this.
- As the Good Book Says...: Graffiti in 1's Death Toll campaign references it.
- Background Halo: In the poster for The Sacrifice.
- Badass Beard: Bill.
- Badass Grandpa: Again, Bill. Coach may count.
- Badass Normal: The Survivors. A war vet, a biker, an office worker and a film buff taking on thousands of zombies with nothing more but the items they can scavenge from random households.
- Badass Abnormal: The main reason why they survived all the shit hurled at them is that they're immune.
- Bad Cop, Incompetent Cop: The military and CEDA respectively. In the comics, the military is merely useless instead.
- Balcony Escape: Used a couple of times in apartment complexes. Notably, the survivors escape a Tank in the intro by having a balcony collapse on it.
- Bare-Fisted Monk: Deconstructed in Survivor graffiti, believe it or not.
"October 2nd Johnny killed 12 Infected with his bare hands"
- Bilingual Bonus: A piece of saferoom graffiti in The Sacrifice is in Japanese - Louis gives the translation, but only the English half. Fluent speakers alone would be able to read aloud the characters he translates.
- Bittersweet Ending: The final part of the comic shows Bill jumping off the bridge to restart the generator so the bridge can be fully raised. He gets ambushed by three Tanks and gets killed, but the survivors were able to outlast the horde and take the boat to the Florida Keys to spend the rest of their lives in, thanks to Bill's Heroic Sacrifice.
- By the Lights of Their Eyes: The Witch. See Power Glows below.
- Clown Car Base: Occasionally, you may see an entire horde (30 or so Infected) emerge from a closet or bathroom.
- Cluster S-bomb: The survivors say "shit" a lot.
- Cool Car: The armored van at the end of Crash Course, which quickly catches the survivors' attention as a means of escape.
- Cozy Catastrophe: Francis has little difficulty adjusting to the Zombie Apocalypse.
- They eventually travel to Florida to hold out the apocalypse there.
- Crazy Survivalist: The survivors, with off-screen NPCs and graffiti taking it to extremes.
- Dead Hand Shot: The box art.
- Death World: Umm, zombie apocalypse. Par for the course.
- Dedication: If you die during the finale you don't get to respawn, but as long as at least one character escapes, the credits will start with "In memory of [Player Name]".
- Did You Just Flip Off Cthulhu?: The only way to distract a Tank from pummeling a downed survivor to death is to melee him, which otherwise serves absolutely no purpose at all.
- Dungeon Bypass: Guarding the doors and windows is all well and good, but more often than not the horde just crashes through a wall.
- DVD Commentary: Like all Valve games, both Left 4 Dead games have a commentary mode, where you can play a campaign that contain commentary nodes which will play commentary audio from the developers. You're locked in Easy difficulty and zombies will ignore you. Naturally, you can't earn achievements this way.
- Elevator Action Sequence: The fourth level of No Mercy requires holding off the horde while waiting for the elevator. Subverted on the elevator ride itself; any first time player will constantly give the missing elevator panel nervous glances.
- The panel is intact in the sequel's port, to counter Spitters getting a cheap shot.
- Elite Zombie: The special infected.
- Escape Convenient Boat: Quite a few. One of them actually kicks them out, though it's only referenced in dialog.
- Everybody's Dead, Dave: The only non-zombies you hear from in the game are the playable survivors, the (sometimes) unseen pilots and drivers who rescue you at the end of each campaign, the occasional psycho/weirdo, and occasional gunfire off in the distance.
- Film Posters: One for each campaign. You can see them here.
- Fire-Forged Friends: The Survivors again.
- Fly At the Camera Ending: The helicopter in No Mercy.
- Foregone Conclusion: The poster for the Survival Mode-only level, The Last Stand.
- Both the campaign and the comic for The Sacrifice, given that they came out after The Passing.
- Four-Philosophy Ensemble: Francis as Cynic (hates everything), Louis as Optimist (hopeful), Bill as Realist (experienced) and Zoey as Apathetic (zombie fan).
- Game Mod: Countless ones, this being a Source Engine game and all.
- Heroic Sacrifice: The chopper pilot in No Mercy was making repeat trips into the infection zone, getting infected for their trouble. They still kept the rotors spinning right up until the bitter end.
- The entire purpose of The Sacrifice DLC.
- Hide Your Children: The Infected are invariably adults.
- Hollywood Darkness: Valve uses a fog effect in some areas to mimic the Hollywood technique of "smoking the set", which conventionally uses a fog machine to help create atmosphere in "dark" areas. The fog catches the little light available, which makes everything slightly brighter, and allows viewers and players to see the silhouettes in the distance when they would otherwise be indistinguishable against the dark background.
- Idle Animation: The infected alternate between leaning on the wall, sitting in despair, barfing up their guts (literally) and killing one another. The survivors alternate between stretching, wiping their faces, or picking their noses.
- Incendiary Exponent: Every Special Infected can attack you whilst on fire. Hunters will actually do more damage while aflame, and tanks become faster.
- Incredibly Lame Pun: The characters and achievements are quite fond of these.
- Jerkass: Francis is rather belligerent towards Louis, which, in turn, gets Bill to be a jerk to him.
- The Survivors think of Crazy Church Guy as one.
- Last Stand: Survival mode.
- Leaning on the Fourth Wall: Done in the Sacrifice comic with Zoey and her dad.
- The campaign itself has a bit of this, too - Bill's plan for escaping the infection is to boat to a secluded island, as he says "As far as we know, zombies can't swim." They really can't.
- Leitmotif: Every Special Infected gets two of their own tunes, one that plays when they spawn, and another that plays while they're attacking a Survivor.
- Left for Dead: A regular occurrence in the rush for the rescue vehicle. With an incoming Tank that must not enter the rescue vehicle, this choice must be made often.
- Made of Plasticine: It's not uncommon for the basic infected to be graphically dismembered by a shotgun blast, a few stray bullets, or being bashed with a rifle butt.
- Message Board: Saferoom graffiti really acts like this, although people who leave the saferoom usually don't return. Ever.
- Musical Spoiler: Musical warning is given for when a horde appears, a tank appears, or when a witch is nearby. It also plays softly whenever any special infected are nearby, making those who know each one's theme music able to know one's nearby even without hearing them or seeing them.
- Near-Victory Fanfare: "Skin of our Teeth", a fast-paced, intense tune that plays when the rescue vehicle arrives.
- The Nicknamer: Francis has a tendency to call his team by pet names on occasion, such as calling Louis "Louie." He'll also call the Hunter cowardly names like "little wussy" and "sweatshirt-wearing sissy."
- Night of the Living Mooks: The game pretty much shuffles the Horde's character models at random. The sequel give so much variety of appearances for individual parts of the zombie that the chances of seeing the exact same zombie twice is maybe 1:1000.
- No Animals Were Harmed: Parodied, "X zombies were harmed in the making of this film."
- No Bikes in the Apocalypse: Usable vehicles are always fuel-powered, no exceptions. And they never have any fuel in them, either.
- Non-Fatal Explosions: Zigzagged; while explosions from grenade launchers, pipe bombs, propane/oxygen tanks and barrels will deal lethal damage to any infected within range, they'll hurt survivors for maybe 5-10 damage at most on Expert.
- Not Using the Z Word: Played straight and averted. The survivors call them zombies, but subtitles consistently refer to them as "infected" regardless of the dialogue.
- Oh Crap: The usual reaction the player characters have when a Tank appears.
- Offscreen Moment of Awesome/The Last Dance: Bill's death, fighting three tanks. Only seen in the comic, though it can be played out to some extent in the Sacrifice campaign.
- The Power of Friendship: Literally. Nothing will get you killed faster than leaving your fellow survivors behind and trying to Rambo your way through the next level alone.
- Real Is Brown: Used for how a zombie would see the world. Players taking the role of the zombies in VS mode will see the world completely brown.
- Room Full of Crazy: Church Guy's safe room.
- A couple of safehouses are covered in bizarre ramblings, which other survivors mock or show horror at.
- Running Gag: Francis' berating of Zoey for shooting a zombified pilot, which continues when the survivors in 2 berate Nick for doing the same.
- Francis' cover story and mistaking zombies for vampires.
Don't worry, we're cops!
- Francis hates everything. Seriously. Current count: Vans, Trainyards, Hospitals, the woods, Lawyers, Doctors, Ayn Rand, tunnels, stairs, elevators, planes, mazes, barns, helicopters, turnpikes, cops, water, Canada, Canadians, Zombies, Infected, His Traveling companions, islands, etc.
- Schmuck Bait: Go ahead, play some Midnight Riders at the wedding. You know you want to. We're sure the bride won't mind.
- Screams Like a Little Girl: Francis, when he is attacked by a Hunter or when downed.
- Shaky POV Cam: A touch in the opening cutscene for the first game. Makes sense, considering Versus Mode.
- Shameless Self Promoter: Oh, Valve, you sly dog:
Zoey: I love Steam.
- Ship Mates: In-universe example--Ellis makes a suggestion to Rochelle that her and Francis should double date with him and Zoey.
- Shipper on Deck: Rochelle and Coach don't mind pushing Ellis towards Zoey. Nick... not so much. Though even he will sometimes go along with it too.
- Sinister Subway: The second level of "No Mercy" goes through a subway.
- The Smurfette Principle: Due to the genetic nature of immunity, men have a 3:1 chance of being immune compared to women, which is why there is only one girl in both sets of survivors. Assuming humanity survives this Infection, expect Gender Rarity Value to come into play.
- Stand Alone Episode: All of the campaigns in the first game start with the discovery of an evacuation point and end with the survivors successfully escaping. The developers originally planned to have the campaigns lead in to one another, after the survivors escape but have their escape method fail somehow, but then found that it was too depressing to succeed only to learn how that you'd ultimately failed. Averted in the second game, where the campaigns lead directly into each other. In addition, Crash Course ties together No Mercy and Death Toll, and The Sacrifice comic confirms that all the campaigns from the first game are tied to one another (and, of course, tie into... well, The Sacrifice and The Passing.)
- Suspiciously Apropos Music: In "The Passing", you can play a song about leaving someone (by the Midnight Riders) near a Witch who was infected at a wedding.
- Technically Living Zombie: The Green Flu doesn't kill its victims, so this applies to all the Infected.
- Terrified of Germs: Averted, the survivors don't mind being covered in zombie guts. Or fishing pills out of urinals.
- Nick plays it straight.
"A little hand sanitizer and we wouldn't be in this mess."
- The Tetris Effect: Play the game for a good hour or so. Close your eyes. See the zombie horde rushing towards you?
- This Is Gonna Suck: Bill's reaction in the intro movie after a car alarm goes off.
This is gonna get bad.
- Token Minority: Louis in the first game. Averted in the second game with Coach and Rochelle.
- Typhoid Mary: All of the playable survivors are asymptomatic carriers for the virus.
- The Unintelligible: The Charger is clearly saying something, but no one can really agree on what it is.
- Well-Intentioned Extremist: The military and government in general is full of them.
- Wham! Episode: In "The Passing", Bill is dead. You get to watch him die in "The Sacrifice". You don't specifically have to sacrifice Bill, but you do have to sacrifice someone.
- What Happened to the Mouse?: The loose ends of the people that rescued the L4D1 survivors are tied up in the Sacrifice comic, L4D2 shows or explains what happens to all in the next campaign.
- Xtreme Kool Letterz: Left. 4. Dead. No explanation should be necessary.
- Zoey Is About To Shoot You!: Several of the campaign posters.
- Zombie Apocalypse: Duh.
- Zombie Gait: How individual zombies walk until they see you.
Meta (Community/Developer/Supplemental Material) Tropes
- All There In The Opening: The opening movie does a superb job explaining how to not die.
- Artistic License Engineering: Specifically Architectural Engineering; some of the maps feature buildings with impractical or outright impossible layouts for normal use. The offices in Death Toll's Riverside (the ones immediately before the street crescendo event) have no interior doors in them. The players enter and exit through a balcony on either side, so how would the office workers normally enter?
- Bag of Spilling: The intro cinematic shows all the survivors using guns that they don't start with. But during that intro, they either drop them, run out of ammo, or are disarmed, and so when the game opens they're just toting pistols. Additionally, this happens at the opening of each campaign as well.
- Character Filibuster: The Crash Course campaign features a saferoom with a wall covered in a massive Purple Prose poem...And equally-classy replies to it such as "QQ" and "Cool story, bro!"
- Darker and Edgier: The Sacrifice comic zigzags between this and more snarks per mile than the games.
- Deliberately Monochrome: After being downed and revived twice, you see the entire world in black and white, complete with blurry peripheral vision and red item highlights. If you're not healed, you will die. The developers included this because playtesters were frustrated when inexperienced players were repeatedly going down and delaying the group.
- Dirty Business: In order to halt the spread of the infection and save what ever non-infected people they can, the military in The Big Easy made it their policy to gun down carriers (people who don't turn but can spread The Virus) by the hundreds, maybe thousands. Whether this makes them Anti-Hero or Knights Templar is open to debate.
- Downer Ending: The Sacrifice.
- Easter Egg: Found among the apartments in No Mercy is "The Orange Box" cereal.
- In the same campaign, the train station has ads for "Orange Box Juice".
- Edge Gravity: If your character steps off a ledge, he or she will automatically dangle off the ledge, holding on with their hands for dear life for as long as they can until a teammate helps them.
- Exploding Barrels: In The Sacrifice campaign.
- Game Mod: The Mutation game modes that rotate every second week.
- Griefer: Being a team based game, it is extremely easy to grief other players. Even if the griefer gets kicked, they can just join a new game and do it again to others. This also results in Heel Face Turn because you never know who will be the first to shoot you dead when it is time to escape.
- The mutation, Room for One, is all about griefing your team when the rescue arrives since only one survivor is allowed to escape instead of the whole team.
- The griefing problem has been eased somewhat by the 2011 holiday patch that allows players to block a griefer from joining any of their games.
- Leeroy Jenkins: Mostly applies to newbies who keep making common mistakes, such as running ahead of everyone (which usually gets them killed and are too far away to be saved in time), angering a Witch without having the right gun for it (only shotguns can kill her instantly with a well placed headshot), or flinging Molotovs like a hot potato and setting other players on fire from it.
- Oh, there's more. See the trope page itself for the huge list.
- Let's Play: Both games have one on the Something Awful forums, with the first already archived and the second temporarily on hiatus.
- Letters 2 Numbers: The title.
- Lighter and Fluffier: Alexandria Neonakis' adorable cartoony designs for the Special Infected, which appear on the licensed Christmas cards, previous Valve Store site headers, and even spawned a series of plushies that make the various Infected's signature noises when squeezed. So far, they've released Boomer, Hunter, and Tank, although a prototype of a Jockey hat is floating around online somewhere.
- Mythology Gag: Bill, during early development, shared his last name with Half-Life's Barney Calhoun.
- "Still Alive" can play on jukeboxes, albeit very rarely.
- Only Six Faces: Played straight.
- Our Zombies Are Different: Of the infected, easily-enraged sort much like in 28 Days Later and various types of Elite Zombies.
- Poor Communication Kills: This will literally be your game ender online if you or the rest of your team fail to talk or at least call for help if being pinned by the infected, especially in Realism and Realism Versus modes where you can't spot each other with glows anymore. Lots of games have been lost due to people simply not speaking up.
- Pun-Based Title: You play as four survivors, who are left for dead.
- Rage Quit: Consult the VG Cats guide.
- Self Fanservice: Go look at how the Hunter, Witch, and Smoker look in the game. Pretty hideous looking zombies, right? Now go look how they are drawn in a lot of fanart. Notice any differences?
- Serious Business: Handfuls of people take the game very seriously and will scream at you or call a vote to get you booted if you do anything they don't like (not the Too Dumb to Live type player mind you). More noticeable in VS mode where people will yell at you for not saving them from the infected quick enough and/or yell at you if you don't do enough damage to survivors or just plain outright miss your attacks. 
- Superpower Lottery: As far as zombies go, the Tank and Witch have won this.
- The Virus: If you're
unlucky enough, you turn into a constantly crying, always-guilty Witch, a head humping horny midget, an acid spitting hag, a giant armed freak, an exploding fatass, get Gene Simmon's tongue, become a flying Parkour expert or turn into the Hulk.
- Visual Pun: The boxart is a zombie's left hand holding up four fingers, with the thumb ripped off. Same thing in the game's intro.
- In the trailer for The Sacrifice, a common infected who gets hit by a car falls to the ground and only its hand is visible on the camera. Its thumb is missing, and its hand twitches so to appear to be holding up the number two briefly; making reference to the box art for the second game.
- What Do You Mean It's Not Awesome?: Crescendo Events are triggered by seemingly harmless everyday actions, such as calling an elevator, or opening a fire door. The problem is, every door and piece of machinery in Left 4 Dead's universe is ridiculously loud. While you wait for the slowest elevator in the history of creation, you must fight off wave after wave of Infected aggressors, who have declared war on you, and your noisy machines too!
- Artificial Brilliance: The Special Infected are quite smart and are very wary of the presence of the players. Hunters and Boomers will always try to hide around corners or behind thick shrubs so that they can ambush the players. The two may also tag team players if a player is caught by a Smoker. Smokers will attempt to run away if their attack fails and Hunters will escape by repeatedly jumping away if they are shot at from a distance. Tanks can try to avoid fire the player makes, assuming the player sets the fire off too early. While they can be quite stupid at times, it doesn't happen too often. Tanks are now much smarter in the sequel. When they down someone, they will usually go chase the other survivors instead of just pounding one till they're dead and become a sitting duck. Though pounding one of the survivors to death is actually a smart move and somewhat terrifying, there's a reason you were never encouraged to do that in versus.
- The Common Infected themselves show signs of this - instead of running straight towards the Survivor, they tend to run around in circles, avoiding bullets while attacking the Survivors to the sides or even the back.
- Hunter and Smokers will occasionally retreat if spotted, and try to get to places that the survivors can't reach easily before attacking.
- A simple matter, but AI survivors will always pair up with them if two human players split up.
- Artificial Stupidity: Although not too horrible, the Survivor AI has many infamous quirks. This is a great reason to play the game with actual people.
- Aura Vision: Used to find teammates as Survivors and used by Infected to find Survivors health and location.
- Back Stab: Shoving an idle common from behind is a One-Hit Kill.
- Bad Boss: The Director in Versus mode. Between showering the survivors with first aid kits and often not bothering to send a horde after a boomer attack, it clearly hates the Infected players even more than the Survivors.
- Boom! Headshot!: Played straight, to Your Head Asplode levels with common infected.
- Mercilessly averted with the Tank, which receives the same damage from headshots as being shot anywhere else.
- Bottomless Magazines: The players must reload, but they've endless ammunition for their sidearms and supply caches provide infinite replenishment for your main weapons.
- Calling Your Attacks: Played straight by survivors throwing grenades, invoked with the special Infected's vocalizations giving them away.
- Cherry Tapping: It's possible to kill even the Special Infected just with the secondary melee attack. Just don't try it on the Boomer.
- Chiaroscuro: Actively exploited by the developers to guide the players, after they noticed playtesters' tendency to move toward the brightly lit areas.
- Critical Existence Failure: Averted with the survivors. When seriously injured, you run slower, jump lower, while on pain pills or just brought up by teammate your health is constantly dropping, and at 1 HP you slow to a crawl. If your health runs out and you're not ready to die, you drop to the ground, only able to use pistols, and slowly bleed out until you die or are saved by an ally.
- Played straight with the infected. Play long enough and you'll see a zombie run up to you that has had both of its arms shot off. (What does it plan to do then, bite you?)
- Damage Sponge Boss: Tanks, full stop. Four Survivors starting a level have a group total of 400 HP. On Normal difficulty, the Tank has 4,000.
- Death Is a Slap on The Wrist: Dying does not mean you are forever gone from the game. You will just respawn in a closet or come back in the next map. Versus mode prevents you from coming back until the next map and dying during a finale on any mode gets you Killed Off for Real.
- Death Is Cheap: You can be rescued from a closet in campaign mode or just simply respawn in the saferoom in the next chapter.
- Death or Glory Attack: Cr0wning the Witch.
- Difficulty Spike: The jump from Advanced difficulty to Expert is huge. On Advanced, a common infected will deal 5 points of damage if they hit you in the front whereas they do 2 damage on Normal and 1 on Easy. On Expert, common infected can cause 20 points of damage in the front. Hunters can slice you for up to 40 points of damage, dealing the most damage out of all of the infected on Expert except for the Tank, who can instantly bring you to incapacitation in a single strike. Not to mention that Witches, which previously incapacitated you in one hit as well, now just flat out kill you.
- The Sacrifice was a huge bump up from all the other campaigns, mostly due to its finale. Unlike the other finales, the hordes AND the Tanks attack at the same time. And there are three sets rather than two now. And one achievement involves setting off all three at once. And then just when you think you've made your escape, the lift engines stall and you have to sacrifice a survivor to go re-activate the lift. With 3 more tanks and another horde all gunning for him.
- The Director Is A Cheating Bastard: Unusual, in that the Director is supposed to be continuously tweaking the challenge of the game up and down based on how well the players are doing. However, on Expert, it's moments of mercy are extremely brief.
- This goes for the survivor bots too, as they have aimbot
-likeaccuracy, and cannot directly cause friendly fire(being able to literally shoot through others). It works, as a half-decent human player is still more efficient overall (due to other factors like bots not being able to use grenades or any particular strategy beyond shooting things), yet a team isn't completely screwed if a player leaves mid-game.
- Under certain conditions, survivor bots will grab items through walls. Players can't, though in "Death Toll" there is at least one stairway you can revive downed teammates through.
- Any special infected (other than witches or tanks) can slash you with their claws if you manage to shove them. No "attacking while staggering" animation or anything, blood literally just pulls itself out of your chest.
- In co-op and other modes where the special infected are AI-controlled, the specials can spawn inside the safe room at the end of the level, leading to fun times. In versus, where the specials are human-controlled, you cannot spawn in the ending safe room.
- This goes for the survivor bots too, as they have aimbot
- Everyone Chasing You: The horde.
- Exploding Barrels: Gas cans, propane tanks, oxygen tanks, and actual barrels in the Sacrifice campaign.
- Falling Into the Cockpit: Versus mode, infected team. While a player can run through the campaign mode to build up their survivor skills before going in, infected players have to learn it all on the fly for their randomly assigned characters.
- Fetch Quest: Going through waves of infected for some gas.
- Genre Savvy: Zoey spent her time in college watching zombie horror movies, so she knew how to survive.
- Ironically, ties into Zoey's background: she watched zombie movies with her dad a lot. When he was bit, he had her kill him, as per zombie movie tropes. Turns out... he was immune.
- Goomba Stomp: Jumping on a common Infected's head is instantly fatal. Doesn't apply to special infected.
- Physically being on top of a zombie counts as a stomp, thus an instant kill, which leads to a hilarious moment where you can literally walk over a zombie lying on the ground and kill it from just stepping on it.
- Gravity Barrier: keeps you away from a zombie breeding ground and to keep you moving along to your safehouse.
- Griefer: Per GIFT, you're guaranteed to come across them in public matches.
- Playing as the infected is basically griefing the survivors as the goal of the game. The griefers are getting their kicks from the game itself most of the time!
- Harder Than Hard: Expert mode is Exactly What It Says on the Tin. Only experts can expect to survive.
- He's Just Hiding: Literally. Whenever one of the guys die, they're found later trapped in locked closets (or respawn in the next saferoom). It was meant to reflect how survivors get rescued in zombie films.
- Averted in the final chapter of each campaign after the rescue vehicle has been summoned. Dying means you get Killed Off for Real.
- Hit and Run Tactics: This is usually the best way to deal with the Tank, by setting it on fire with a molotov and/or pumping it full of lead while evading it. Just make sure that you're healthy enough that you can run fast, and that there's room to run.
- Hitbox Dissonance: Hitboxes for hunters move in front of them when they pounce, which makes them extraordinarily difficult to knock out of the air with even the slightest bit of lag.
- Hold the Line: Occurs in all crescendos and finales(except a couple in the Parish) as well as survival mode.
- Hyper Awareness: meta example. The best players exhibit this, being aware of all the directions from which infected could attack and keeping their eyes (and ears) open for incoming specials. In comparison, the AI bots (as mentioned above) are Lazy Backup with a horrific case of Selective Obliviousness.
- Interface Screw: Your vision becomes monochrome with red outlines for items if you're incapped twice without using a medkit.
- Invisible Wall: Only the Infected in Versus mode will run into them, and if you get close enough they stop being invisible... instead they become labeled "wrong way!"
- It Can Think: The Director is actually a rather well working AI system. Depending on the difficulty, it will decide when to place more zombies to hinder your efforts. On Expert difficulty, it just wants you dead and doesn't pull any punches.
- Kaizo Trap: The end of "The Church" in Death Toll. However, this is rarely ever a problem since you can fire before the infected can hope to attack.
- Contrary to extraordinarily persistent rumors, it is not possible for Church Guy to become a Tank or Witch. As demonstrated and explained in this video.
- It is, however, entirely possible for a Tank or Witch to spawn in the safe room on any map. This is disastrous with AI Survivors, as being near a safe room triggers a behavior override that has them hustle into the safe room door. They have no problem at all with bumping into the Witch in the process.
- Contrary to extraordinarily persistent rumors, it is not possible for Church Guy to become a Tank or Witch. As demonstrated and explained in this video.
- Killer Game Master: The AI director. Particularly on Expert mode, when he stops even pretending he doesn't hate your guts.
- Luck-Based Mission: Depending on where enemies spawn and what types they are, along with what items you find, you can either have a smooth sailing game or a nightmare of just trying to survive.
- Metronomic Man-Mashing: The Tank does this to some zombies in the intro movie.
- Muscles Are Meaningless: The Witch is a small girl with relatively thin limbs (apart from the vicious claws)... limbs with which she can knock you down/kill you outright faster than any other Infected. Including the muscle-mountain Tank. Justified, at least in part, by those claws and perhaps by what could be argued as an overactive metabolism - she's clawed most of her own clothes off, can't stand the light of day, and is drawn to the smell of sugar. The Tank's bulk is more weight that his muscles have to overcome (though you don't want to get in the way of his fist once it's moving, and even less in the path of a car he's just flung at you - that can incap the entire team in one swipe), whereas the Witch's constant supercharge and lack of excess weight means she can swing those claws with vicious speed.
- My Rules Are Not Your Rules: AI-controlled infected can spawn anywhere, melee while stumbling, climb things player-controlled infected cannot, and AI-controlled hunters even have a lunge move players cannot perform.
- Never Split the Party: The game is built on this trope. Get separated or lose track of your teammates and You Are Already Dead.
- Occasionally averted in Expert and Versus matches when one survivor staying in the saferoom with the door closed can be the difference between success or failure.
- There are also a few jarring situations in which you have passed a Point of No Return and cannot go back and help your teammates. This just reinforces the original lesson, since you are forced to soldier on short-handed.
- Nerf: The shove motion has been nerfed with the addition of fatigue: do it too many times and there starts being a delay before you can do it again. This punishes the fact that you can get completely surrounded and need to shove your way out.
- Nietzsche Wannabe: A lot of the graffiti is this. It gets shot down by both the cast and other graffiti.
- No FEMA Response: CEDA tries to respond to the "Green Flu", but gets overwhelmed. Inevitably, every time the Survivors try to get to a CEDA evacuation point, it'll be destroyed with nothing but corpses to show for it, and they'll end up having to escape another way.
- Notice This: Witches inexplicably cast a red light in darker areas where you would otherwise have a hard time noticing them.
- Pretty Little Headshots: Headshots on witches remain effective but lack the gruesome aftermath, even if you One-Hit Kill her with a shotgun. Same goes for every Special Infected, and Commons if you're using the pistols or the Uzi.
- Regenerating Health: Inverted. Pills and getting picked up from incapacitation add a temporary buffer of XX health to your HP (differs from action to action), which disappears as time goes on.
- Respawning Enemies: You can surely expect to see all infected more than once.
- Scripted Event: Generally subverted, but there are a few played straight such as an airliner crash.
- Self-Imposed Challenge: Several have achievements for them. No examples, please.
- Sequel Difficulty Spike: The Sacrifice is much harder than other campaigns in spite of being shorter.
- Sound-Coded for Your Convenience: Major gameplay-changing events(horde attacks and tanks or witches being startled) change the music. Special infected spawning are accompanied by their unique theme (except in Versus) and their vocalizations give them away.
- Southern-Fried Genius: Ellis.
- Speed Run: How some players play Versus mode as survivors. Whether this is good or bad obviously depends on opinions and situations.
- Standard FPS Guns: Pistols, shotguns, assault rifles, mounted machine guns, sniper rifles, and grenades.
- Stop Helping Me!: The survivor AI when it comes to healing. They will do their damn best to keep you going, but ignore anything else occurring at the moment, and always try to heal you when you don't need it. Expect to run around frequently while holding pills or a medkit just for the sake of not being interrupted.
- Take Up My Sword: If a survivor dies, another can take their weapons and items.
- Total Party Kill: Tanks can cause this single-handedly, especially if the Survivors are clumped together and he swats a car at them. Also can happen when a good ambush is pulled off in Versus.
- Averted with the Witch, who is programmed specifically to only be aggressive towards one Survivor. Not that things don't go off the rails every now and then...
- Video Game Caring Potential: Given that you're trying to survive as a team in a zombie apocalypse, you can either always have your team's back, even making sacrifices to save all of their lives...
- ...or you can completely ditch them and leave them at the mercy of all the ruthless zombies, taking all the weapons and health for yourself.
- Video Game Cruelty Punishment: Of course, the Director gets pissed at uncooperative play, so he'll often spawn less items and more zombies to target the cruelty-inflicting players.
- Videogame Set Piece: Most prominently in the last stage of Dead Air, when the survivors leave the saferoom to see a plane on approach go out of control, impact the ground, and slide in on fire before exploding.
- Violation of Common Sense: Downing a whole pack of pain pills at once would be fatal in real life, but somehow is a good idea if you're low on health.
- In the zombie apocalypse, you don't need to remove the cap to swallow a whole bottle of pills.
- If you get mobbed by common infected, setting yourself on fire with molotovs or blowing yourself up with a grenade launcher will usually clear your space a lot faster than to keep shoving them away or trying to hack at them all with melee weapons. You'll suffer self inflicted friendly fire damage, but that will be small compared to trying to clear out zombies invading your space without said methods.
- There are some cases where team killing is actually justified. If someone is about to die and there's nothing to heal with, players will usually kill the wounded survivor and then let them respawn in a closet or revive them with a defibrillator: both methods bring the Survivor back with 50 points of health. If no one speaks of this and do the deed, they could be mistaken for a Griefer.
- We Cannot Go on Without You: If there are any bots on the team, you'll have to start the level over again if all the human players are dead, regardless of if there is a bot player alive. It becomes mind-boggling when playing against a team of bot Survivors in versus mode and they are capable of moving through the level on their own without the guidance of a human player.
- It gets even better when you jump off the roof of No Mercy before starting the finale with only bot allies. Game over starts playing, bots start the finale, you respawn in the closet due to finale starting, bots free you, then the game restarts the chapter anyway.
- What the Hell, Player?: Shoot one of your fellow survivors, and they'll call you out for it with scripted response.
- Whoring: Players could get minimal damage from hordes and the Hunters by constantly spamming the melee attack button, which created problems for Versus mode. Valve have made a Nerf for it where melee attacks now require a quick cool down before being used again (though it's still possible in campaign mode).
- You All Look Familiar: The basic infected actually have a small number of basic models but are made to look different with various filters, like clothing and blood spatter. The Unique infected all look exactly the same since they wear uniforms.
- You Have Outlived Your Usefulness: Special Infected which are stuck or otherwise unable to catch up to the Survivors will occasionally be killed off by the Director, with the death noise often being faintly audible to human players, particularly in the case of Boomers and Smokers.
- Tanks will fall victim to this unless they can attack the players within a given amount of time. It's rare but it does happen occasionally.
- Infected players can manually trigger this when they are at a certain distance behind the survivors, allowing them to skip the respawn time that would happen if they jumped off a cliff instead.
- Your Head Asplode: Shots to the head of regular zombies with more powerful weapons leave only their neck and a Pink Mist.
- Zerg Rush: The AI director will send these at you at random, when a boomer vomits on you, in pre-programmed Crescendo Events where you're forced to make a ton of noise to continue moving, or if you accidentally set off a car alarm, or whenever he's bored, which is all the time. The normal infected also like to rush pipe bombs because of the smoke detector alarms rigged to them.
- AKA-47: Done subtly: although most of the guns are not named, zooming in on the gun models reveal they are made by fictional companies (example, the pistols in this game are made by "Finleyville Armory").
- Awesome but Impractical: The minigun, which can shred oncoming hordes like no other, is never positioned so it can effectively cover more than two of the generally five or so directions that zombies can come from.
- Bottomless Magazines: Pistols have infinite ammunition. This is for gameplay reasons; they don't do as much damage as regular guns, and they're the only weapons you can use while incapacitated.
- Did Not Do the Research: The scoped rifle is referred to as a "Hunting Rifle"; however, in Pennsylvania, where the game takes place, hunting with a semi-automatic rifle is illegal.
- Gatling Good: You get the odd mounted minigun here and there. It's set up so that the gunner will have to be covered by the other Survivors, though.
- Guns Akimbo: All characters can find and dual wield a second pistol for extra ammunition in the magazines.
- Incredibly Obvious Bomb: The pipe bomb is one, but with good reason - its red light and high-pitched beeping make the standard infected flock to it, making it less a question of where to throw them and more a question of when.
- Kill It with Fire: Molotov cocktails and gas cans.
- Molotov Cocktail: Lovely, lovely, molotov cocktails...
- One Bullet Clips: Originally averted before its first patch - reloading magazine-fed weapons early caused your character to just toss the entire magazine regardless of how many bullets were left, though as stated this was near-immediately patched out. Shotguns also work as they always have in Valve's games (load one shell at a time, meaning faster reloads when closer to fully-loaded and able to cancel mid-reload to shoot at zombies), and pistols are also exempt as they have infinite ammunition.
- Pink Mist: Pipe bombs produce this effect rather than gibs.
- Ranged Emergency Weapon: Pistols.
- Short-Range Shotgun: Averted. The shotguns are a viable weapon choice, even in open areas.
- Sticks to the Back: Every weapon and inventory item except pistols (they get holsters), pills, and grenades.
- They all turn or can't stand the survivors
- In fact, in most Versus games, when someone becomes the Tank, all the infected players put all their hopes on the Tank player and expect him or her to to kill the Survivors in one go. What most people don't realize that the Tank alone cannot kill the Survivors unless the players are extremely stupid and the Tank needs support from the other infected. If you're the Tank and get caught on fire or die without killing at least one player, expect most people to call you a fail Tank.
- except tanks and witches
- She was originally intended to be a threat to all survivors, running after every one of them and incapping all, but the developers figured out she was too hard to deal with like this