[[quoteright:330:http://static.tvtropes.org/pmwiki/pub/images/L4D2.jpg]]
[[caption-width-right:330:[[CloudCuckooLander Ell]][[MrFanservice is]], [[TeamDad Co]][[ReligiousBruiser ach]], [[SassyBlackWoman Roch]][[TeamMom elle]] and [[DeadpanSnarker Ni]][[LoveableRogue ck.]]]]

->'''Coach''': ''"Wait for official instructions. (laughs, tossing away instruction sheet dismissively) 'Wait', my ass."''\\
'''Ellis''': ''"Kill all sons-a-bitches. [[DramaticGunCock *racks shotgun* ]] That's ''my'' 'ficial instructions."''

The 2009 sequel to ''VideoGame/Left4Dead''.

The plot is roughly the same as the last game, a deadly virus epidemic has claimed the country. You play as one of four survivors trying to make their way though bloodthirsty hordes of mutant infected to reach safety. The difference this time out is the setting is located somewhere around the [[DeepSouth Louisiana area]].

The game sports a few new features such as three new special infected (The Charger, the Jockey, and the Spitter). Also introduced in the sequel is the new Scavenge mode, a eight-player mode similar to Versus where the point isn't to reach the safe room; it's to collect gas cans. Also introduced is Realism, where most auras are removed (including the ones around teammates), Witches instantly '''kill''' on any mode except Easy, there are no "rescue" closets (dead players only respawn at the start of a new level), and a few other things. The narrative to the game has also changed as each campaign now leads into the next one rather then stand alone (for the most part) like the first game did.

The lead up to the game saw much controversy after it was announced at 2009's E3 and was set to be released in November that year. Unfortunately, Valve's claim at launch of the original game that they would update it following the model of ''VideoGame/TeamFortress2'' updates promptly backfired, as large numbers of people were ''outraged'' that they were expected to buy content they were under the impression they'd either get for free, or get as a mod rather than an entirely new game; this gave rise to [[http://steamcommunity.com/groups/L4D2boycott the biggest outburst]] of "ruined!" cries ever: a 40,000+ people '''boycott'''. A couple months before the sequel was due, Valve flew both leaders of the boycott to Valve's headquarters to playtest the game, where they admitted that it was "well-made". After Valve's release of a new campaign for the original, "Crash Course", and the leaders admitting that the boycott had since become just an anti-Valve group, they decided to shut it down.

This was followed by the ''Left 4 Dead 2'' DLC "The Passing", which [[MassiveMultiplayerCrossover brings the original survivors and the new ones together]] ([[HeroicSacrifice well, three of them anyway]]) and "The Sacrifice" for ''Left 4 Dead'', which lets players choose who makes the ultimate sacrifice and was preceded by a [[http://www.l4d.com/comic/ free comic]]. The latter update also made "The Sacrifice" and "No Mercy" available in the sequel, complete with the original survivors as the playable characters. Cue rumors that Valve plan to make the entire first game available for free in the sequel and more cries of "ruined forever!" Which they did.

The game also received massive critical acclaim for both its MythArc style narrative - the parts of the story they don't tell you, as well as the interactions between the survivors - and for its emergent narrative, in which different aspects of gameplay combined with elements of randomness mean that every single time you play a new, funny story emerges.

Please take a look at the [[Characters/Left4Dead character sheet]] to learn more about the characters and the ShoutOut page for countless [[ShoutOut/Left4Dead pop culture references]].

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!!Left 4 Dead 2 provides examples of:

[[foldercontrol]]

[[folder:General Media Tropes]]
* AbandonedWarehouse: Nearly every campaign features one.
* AbsurdlySpaciousSewer: Has at least two, though both are nearly devoid of any geometry and only require the players to move in a straight line from the entrance to the exit.
* AcceptableBreaksFromReality: Melee weapons would technically break after extended use in real life and Coach could never run for a while without being winded due to his knee injury and excess weight, but these things are ignored for the sake of simpler gameplay.
* TheAloner: In Last Man On Earth, you are the only remaining human [[TheLastManHeardAKnock other than the rescue vehicle pilots and the gun store owner]] (there also aren't any Common Infected or Boomers), in a game built entirely around co-op, no less.
** Since there are still Special Infected, expect tons of ThingsThatGoBumpInTheNight horror (particularly so, since you're alone and any Special Infected could potentially kill you by itself) and [[JumpScare Jump Scares]].
** In a normal game, if you are a long distance away from any of your teammates, every once in a while your character will shout out something like "Hello?" or "Where is everybody?". As you're the only survivor, the character you're playing as will [[NothingIsScarier periodically give out these shouts for the]] ''[[NothingIsScarier entire game]]'' [[NothingIsScarier to have nothing but the sounds of the Special Infected answer back.]]
** Bonus creepy points for the survivor you're playing as [[GoMadFromTheIsolation talking as if the other survivors are still there,]] giving directions, pointing out supplies/weapons on the map, spotting Special Infected for "other people", etc.
** And, as each campaign in ''Left 4 Dead 2'' is connected to the last, and your character still talks as if there were other survivors, in whatever campaign you're playing, this mode gives off the feeling that you were somehow separated from the other survivors between this one and the last one, but since there are also no longer any "normal" zombies anywhere, it suggests that [[NothingIsScarier something... else must have happened along the way, too.]]
* AmusementParkOfDoom[=/=]CircusOfFear: The ''Dark Carnival'' campaign. Complete with {{Monster Clown}}s, the special zombie for that area, along with playable mini-games.
* ArtisticLicensePhysics: the Silenced Submachine Gun has a little cloth strap dangling off its front, serving as a foregrip. When you reload the gun, tilting it this way and that, that little cloth strap continues to stick straight down perpendicular from the frame.
* [[AutobotsRockOut Autobots, Rock Out!]]: The finale to ''Dark Carnival'' is triggered by starting a [[FakeBand Midnight Riders]] concert.
* BadassBoast: In the "Zombie Survival Guide" trailer of Left 4 Dead 2, Nick says this particular gem during the climax of the trailer:
--> '''Nick:''' I have not... come this far... to die now!
** He says the same after being incapped and revived twice.
* BadassNormal: All of the Survivors. [[spoiler:The main reason why they survive all the shit hurled at them is that they're either immune and/or carriers.]]
* BadCopIncompetentCop: The military and CEDA respectively.
** In the comics the military is merely useless instead.
*** That said, the military does act rationally, if harshly. At the end of The Parish they arrange a special helicopter for the 4 survivors because they are presumably carriers. On the other hand, they shoot normal humans who try to get past the barricades without any degree of contact without a second's hesitation.
* BalconyEscape: In the first chapter of Dead Center.
* BaseballEpisode: The [[https://www.youtube.com/watch?v=fVtbLVPgGH4 Batter Up]] trailer shows the survivors fighting zombies in a baseball field, with commentators acting like it's a genuine game.
* TheBigEasy: The game's campaigns chronicle the survivor's trip to the last evacuation zone in New Orleans, culminating in their escape from the overrun city in ''The Parish''.
* ByTheLightsOfTheirEyes: Zombies and the Witch.
* CelebritySurvivor: The [[FakeBand Midnight Riders]]. Possibly averted by Jimmy Gibbs Junior, who can occasionally spawn as a stronger variant of a common Infected.
* ClimacticElevatorRide: In the first campaign, the survivors take an elevator down to the ground floor of the mall where Jimmy Gibbs Jr.'s car (and their best chance of escape) is parked.
* ClownCarBase: Occasionally, you may see an entire horde (30 or so Infected) emerge from a closet or bathroom.
* [[ClusterFBomb Cluster S-bomb]]: The survivors in both games say "shit" a ''lot''.
** Ellis has a line consisting of almost nothing ''but'' the word "shit".
* CoolCar: The Jimmy Gibbs Jr., a Plymouth Superbird NASCAR race car that the Survivors use to escape the Dead Center and Passing campaign.
* CosyCatastrophe: Ellis and Francis have little difficulty adjusting to the ZombieApocalypse.
** Ellis apparently even got an appropriate tattoo in advance, if his dialogue is to be believed.
** Turns out this is the fate of the three survivors of the original game: they make it to an island in Florida and ride it out.
* CrazySurvivalist: The survivors, with {{NPC}}s taking it to extremes.
* CreepyCircusMusic: The entire Dark Carnival campaign.
** [[http://www.youtube.com/watch?v=3qeIwSkzR3k Peanut Gallery Music]] while not exactly "creepy" It's just kinda weird.
** When powering up a Merry-Go-Round (and alerting a horde of zombies) to get through to the other side of the carousel, the song that it starts playing is stereotypical creepy carnival music that's very slow-paced and ominous-sounding. Makes you question how well it did back when the carnival was still actually in operation.
* {{Crossover}}: [[http://kotaku.com/5990832/capcom-and-valve-team-up-for-resident-evil-6-x-left-4-dead-2-title The characters, Witch, and a smaller version of the Tank are Downloadable Content for the PC version of]] ''VideoGame/ResidentEvil6''.
* CrypticBackgroundReference: The only parts of the story that are completely laid out for you are from the single 4-chapter comic ("The Sacrifice"), and the short character bios that each of the Survivors get ([[AllThereInTheManual neither of which are found in-game]]). The rest of the plot that's given to you will only be through random (often campaign-specific) character dialogue, about 99% of which isn't even guaranteed to trigger (usually requiring [[RewatchBonus multiple play-throughs]] if you want to catch everything), or occasionally from significant pieces of the map, but most of all from the writings on the walls of different saferooms (and occasionally elsewhere) of other people who have passed through that area, describing bits of their experiences as messages to others, agreement or disagreement with what the military is/was doing, just how bad CEDA failed, how fast somebody changes into a zombie after being infected, and so forth, but not even those people are in 100% consensus about whatever's been going on, and [[RiddleForTheAges nobody really has any idea what even]] ''[[RiddleForTheAges started]]'' [[RiddleForTheAges the whole thing.]]
* DeadHandShot: The box art.
* {{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]"
* DeepSouth: ''Left 4 Dead 2'' starts in Savannah, Georgia and makes its way to New Orleans.
* {{Determinator}}: Keith, if Ellis's stories are to be believed. The man has been inflicted with almost every injury one could think of (half of which are essentially fatal), and he not only survived, but was one of the first people out on a rescue chopper.
* TheDevTeamThinksOfEverything: In Dead Center, the opening of ''Left For Dead 2'', when the survivors reach the elevator they use the brief lull to introduce themselves to each other. If somebody dies before this point, one of the other characters mentions the dead character's name.
** In the ''Special Delivery'' mutation, Boomers and bile jars would normally be useless since there's no Common infected. Turns out they reprogrammed them so they [[OhCrap attract all the Special infected instead]].
** In scavenge finales, if the players carry red explosive gas cans, then it can be used to fill up the necessary machine as well as the yellow cans used for these finales.
* DidYouJustFlipOffCthulhu: As in the first game, the best way to distract a Tank from beating on somebody is to get right up against him and melee him. Unfortunately, since he no longer focuses on downed survivors, it's not as necessary a tactic anymore, but it's still effective if he has a teammate trapped in a corner.
* DungeonBypass: Guarding the doors and windows is all well and good, but more often than not the horde just crashes through a wall.
* DVDCommentary: 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.
* ElevatorActionSequence: There are a few elevators and lifts to take much like this. The most prominent is the elevator in Dead Center's hotel, which [[spoiler:breaks down when the building is set on fire, and forcing it open causes a crescendo event]].
* EliteZombie: The special infected.
* EpicHail: Are you telling me that summoning a helicopter through a rock concert with fireworks isn't epic?
* EscapeConvenientBoat: A few in the series, the most famous being Virgil's.
* EverybodysDeadDave: The only non-zombies you hear 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.
* EveryoneCallsHimBarkeep: Coach. When the survivors introduce themselves to each other, Coach states that all his friends call him as such and that they (the other survivors) may as well do the same.
** Rochelle lampshades this occasionally if Coach gets killed.
-->'''Rochelle''': "Do you think Coach was his first or last name?"
* FilmPosters: One for each campaign. You can see them [[http://www.l4dmods.com/index.php?option=com_content&view=article&id=15:all4posters&catid=2:news here]].
* FireForgedFriends: What the survivors are.
* FourPhilosophyEnsemble: Nick as Cynic (pessimistic), Ellis as Optimist (naive), Coach as Realist (leader) and Rochelle as Apathetic (level-headed).
* FromBadToWorse: Leading up from the first game, there is evidence that much of the urban parts of America are completely overrun and that the infected are changing even more; just a month after the first case.
** There's a CEDA map in "Dead Center" with markings suggesting that ''the entire eastern half of the United States'' has been written off as unsalvageable, with the exception of New Orleans.
* {{Hammerspace}}: If you have a melee weapon and are incapped (or a chainsaw runs out of gas), this is where the pistol comes from.
* HeroicSacrifice: The light chopper pilots were making repeat trips into the infection zone, [[spoiler: getting infected for their trouble. They still kept the rotors spinning right up until the bitter end]].
* HideYourChildren: The Infected are invariably adults.
* HollywoodDarkness: 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.
* IdiotBall: The reason the Hard Rain campaign ends with you defending a fast food joint with a bright sign is that at the start of the campaign, while getting off the ferry, the survivors simply ''forgot'' to bring a flare gun with them. All four of them assumed that someone else was going to be carrying the gun bag.
* IdleAnimation: 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.
* IncendiaryExponent: Every Special Infected can attack you whilst on fire. Hunters will actually do more damage while aflame.
* IncongruouslyDressedZombie: Lots of 'em.
** The Uncommon infected usually boil down to this, being dressed in construction, hazmat, clown, riot, etc. gear.
** All of the infected at the wedding in ''The Passing'' are dressed in fancy attire, including the Witch bride.
** Possibly taken to its limit in the popular custom campaign ''Suicide Blitz 2''. The finale takes you through a football stadium, and once you reach the middle of it, two Tanks in football gear run in from both ends of the field. It's hilarious, but the realization that even young, possibly college-age athletes in their prime fell to this plague is a bit disheartening.
* IncrediblyLamePun: The characters and achievements are quite fond of these.
* {{Jerkass}}: Nick doesn't ''usually'' go out of his way to be nice.
* LastStand: Survival mode.
* LeaningOnTheFourthWall: Done in the Sacrifice comic with Zoey and [[spoiler:her dad.]]
-->'''Wade''': Remember those zombie movies [[spoiler: I used to sneak you into when you were a kid]], Zoey? ... [[ThisIsThePartWhere Remember the part in all of 'em where]] [[spoiler:they had to shoot the one guy before he turned]]?
-->'''Zoey''': Heh. [[spoiler:*sniff*]] Yeah. We always made fun of that part. [[spoiler:[[TearJerker ...'''BANG''']]]]
* {{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.
* LeftForDead: 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.
** Not to mention what this game was named after.
* LoveableRogue: Nick has a somewhat shady (and probably violent) criminal past, and he starts out with a lone wolf-style attitude, but because of the circumstances he's in, as the game progresses, he's slowly forced to shed that attitude, and learns to trust and respect his teammates (well, respect MOST of them) and almost grows close to them, and sticks with them through whatever they go through. He probably has the most CharacterDevelopment out of any survivors because of this.
** It also helps that he's the character providing most of the game's DeadpanSnarker. He bounces some of the best lines off of [[CloudCuckooLander Ellis]] because of this.
* MadeOfPlasticine: 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.''
* ManChild: Ellis.
* MessageBoard: Saferoom graffiti really acts like this, although people who leave the saferoom probably don't return. Ever.
* MetalSlime: The Fallen Survivor infected in The Passing campaign. They only appear once or twice, have as much health as a Witch, and will run away the minute you attack them. They also carry items like pills, pipe bombs, molotovs, and first aid kits, so killing them is always worth it.
* MilitariesAreUseless: An aversion. While the CEDA is quickly overwhelmed by the zombie invasion, the military is both [[BadCopIncompetentCop far more ruthless and more efficient]] at dealing with it; the evacuation points of the army are still operational, and for what we know of it, they do manage to save people from the zombie invasion.
* MusicalSpoiler: 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.
* NearVictoryFanfare: "Skin of our Teeth", a fast-paced, intense tune that plays when the rescue vehicle arrives.
* TheNicknamer: The survivors will refer to each other and the Special Infected by various nicknames over the course of the first campaign (for instance, Rochelle calling Nick "Suit", Nick calling Ellis "Overalls", Coach calling the Charger "one-arm", Nick referring to the Hunter as a [[BreadEggsMilkSquick "scrawny little bitch I'm gonna kill"]], etc.). The Tank gets a nickname as well, though [[OhCrap none of the survivors are in the right state of mind to think up one]] when they encounter the first one.
** Nick's description of the Tank fits it best: "HOLY SHIT! BIG FREAKING ZOMBIE!"
* NightOfTheLivingMooks: Pretty much shuffles the Horde's character models at random. Also gives 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.
* NoAnimalsWereHarmed: Parodied, "X zombies were harmed in the making of this film."
* NonFatalExplosions: [[ZigZaggingTrope Zigzagged]]; while explosions from grenade launchers, pipe bombs, propane/oxygen tanks and [[ExplodingBarrels barrels]] will deal lethal damage to any infected within range, they'll hurt survivors for maybe 5-10 damage at most on [[HarderThanHard Expert]].
* NostalgiaLevel: All of the first game's campaigns have been ported into the second.
* NotUsingTheZWord: Played straight ''and'' averted. The survivors call them zombies, but subtitles consistently refer to them as "infected" regardless of the dialogue.
* OhCrap: The first time the characters see a tank, they panic (every other time as well, but not to the same extent).
-->'''Coach:''' Holy shit! What is that?! Some sorta... super-ass zombie!?
** At one point, they climb out of a sewer to find... a car yard. Full of car alarms.
-->'''Nick:''' Whoawhoawhoawhoa! Watch where you shoot!
* PaintingTheMedium: The ending to the "Dark Carnival" has you activate the stage effects for a band that was originally going to play. The next two Tank cues then have a very distinct rock feel to them over the original orchestral.
--> '''Nick:''' Hate to break it to you, Coach, but your heroes lip-sync. There's a tape back here labeled "Finale".
* PowerGlows: Witches inexplicably cast a red light in darker areas where you would otherwise have a hard time noticing them.
* ThePowerOfFriendship: Literally. ''Nothing'' will get you killed faster than leaving your fellow survivors behind and trying to Rambo your way through the next level alone.
* PreviousPlayerCharacterCameo: The main appeal of The Passing is this trope. The survivors from ''Left 4 Dead'' assist you in the finale with cover fire and extra supplies. [[spoiler:Bill, however, is dead.]]
* RealIsBrown: 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.
* RunningGag: Ellis' stories about Keith.
** The "shooting the pilot" snafu in "Swamp Fever" counts as a running gag from the original game; "Crash Course" starts off with the survivors standing at the site of a helicopter crash -- the news chopper from "No Mercy" -- and the various possible dialogues make it clear that Zoey had to kill the pilot after he turned (to which Francis is very likely to snark at her over).
* ScareChord: One plays briefly with a piano when a Witch is startled.
* SchmuckBait: Go ahead, play some Midnight Riders at the wedding. You know you want to. [[TemptingFate We're sure the bride won't mind.]]
* ShipMates: In-universe example--Ellis makes a suggestion to Rochelle that her and Francis should double date with him and Zoey.
* ShipperOnDeck: Rochelle and Coach don't mind pushing Ellis towards Zoey. [[{{Jerkass}} Nick... not so much.]]
* StandAloneEpisode:
** Averted with the core campaigns, which lead into one another. ''[=L4D2=]'' also retroactively applies this to the original game's campaigns with the addition of The Sacrifice and The Passing, connecting the story as a whole together.
** Played straight with Cold Stream, which does not fit into the canon of the story and is considered a "what if" scenario. It is currently the only "official" campaign not designed by Valve directly.
* StereotypeFlip: Rochelle may very well be the only black Music/DepecheMode fan you have ever met.
* SuspiciouslyAproposMusic: In "The Passing", you can play a song about leaving someone (by the Midnight Riders) near a Witch who was infected at her wedding.
* TatteredFlag: The Sacrifice DLC campaign begins with the survivors trekking through a zombie infested dockyard that had been occupied by the military and FEMA expy CEDA with the camera prominently showcasing a tattered US flag flapping in the wind. Doubly significant because of the canon death of [[spoiler:Bill, a VietnamWar veteran at the end of the campaign]].
* TechnicallyLivingZombie: The infected ''might'' still even be curable, according to the military. This is most likely wishful thinking.
* TerrifiedOfGerms: 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."\\
"A germ just wiped out the world."\\\
"I am NOT jumping into the- screw it, let's go." (In reference to the [[AbsurdlySpaciousSewer sewer]] on The Parish.)
* TheSmurfettePrinciple: Each group of survivors only has one female.
** While some might think that this is only done to appeal to the [[MostGamersAreMale largely male demographic]], this is actually [[JustifiedTrope justified]] via genetics. The gene for immunity is strongly hinted to be on the X-chromosome, meaning that males only have to receive one immune X-chromosome from their mother to be immune, while females have to have one from both their mother ''and'' their father. Hence, the much smaller proportion of immune females to immune males.
* TheTetrisEffect: Play the game for a good hour or so. Close your eyes. See the zombie horde rushing towards you?
* TokenMinority: Averted.
* TyphoidMary: All of the playable survivors are asymptomatic carriers for the virus.
* TheUnintelligible: The Charger is clearly saying ''something'', but no one can really agree on what it is.
* WellIntentionedExtremist: The military and government in general is full of them.
* WhamEpisode: In "The Passing", [[spoiler: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''.]]
* WhatHappenedToTheMouse: The loose ends of the people that rescued the [=L4D1=] survivors are tied up in the Sacrifice comic, [[spoiler:they all turn, need to rally elsewhere, or can't stand the survivors]]. [=L4D2=] shows or explains what happens to all in the next campaign.
* WhereAreTheyNowEpilogue: Although not in the game itself, WordOfGod has stated that ''Left 4 Dead 2'''s survivors do make it safely to a cruise ship via the chopper that picked them up at the end of the Parish, and the first one's survivors make it to the Florida Keys via boat after the end of The Sacrifice. [[VaporWare Thanks to Valve's track record on making third installments,]] we will probably not get any more expansion on what happens to any of the survivors for a long, long time to come.
* XtremeKoolLetterz: Left 4 Dead. [[CaptainObvious No explanation should be necessary.]]
* ZombieApocalypse: [[CaptainObvious Duh.]]
* ZombieGait: How individual zombies walk until they see you.
[[/folder]]

[[folder:Meta (Community/Developer/Supplemental Material) Tropes]]
* ArtEvolution: The higher polygon count and upgraded lighting effects compared to the first.
* BagOfSpilling: Played straight in the beginning of Hard Rain. After being dropped off to the Burger Tank by Virgil, the survivors realize that they left their bag of guns on the boat.
--> '''Virgil''': I'll drop the anchor just off shore, waitin' for ya. Signal at me when you get the gas.\\
'''Nick''': What are we supposed to signal him with?\\
'''Ellis''': Oh, there's flares in the gun bag.\\
'''Nick''': What gun bag?\\
'''Ellis''': You didn't grab the guns?\\
'''Nick''': Me?! Who died and made me gun monitor?\\
'''Ellis''': [[DeadpanSnarker Pretty much everybody]].
* BiteTheWaxTadpole: The zombie hand on the cover is holding up 2 fingers in the same manner as someone in the U.K. would when telling you to do something unpleasant... Apart from the UK version, where the hand is photographed from the other side, making a "victory" sign.
* BodyHorror: The Special Infected have undergone horrible and probably quite painful mutations from ''Left 4 Dead'' to ''Left 4 Dead 2''--the Smoker especially. The new Special Infected haven't had it easier, either; just look at the [[http://images4.wikia.nocookie.net/left4dead/images/7/75/Spitter2.jpg Spitter.]]
* CharacterFilibuster: The other survivors have to tell Ellis to shut up whenever he rambles on about Keith (and Zoey in the "The Passing" DLC).
* DeliberatelyMonochrome: 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.
* DirtyBusiness: In order to halt the spread of the infection and save what ever non-infected people they can, the military in TheBigEasy made it their policy to gun down carriers (people who don't turn but can spread TheVirus) by the hundreds, maybe thousands. Whether this makes them AntiHero or [[KnightTemplar Knights Templar]] is open to debate.
* DummiedOut: The "fallen survivor" uncommon infected, which was brought back(albeit with a very different ability) in ''the Passing.''
* EasterEgg: And in The Parish, going up the stairs of the store-made-safehouse, you can find a door with an orange light outline.
** In the additional map "Suicide Blitz 2" you can find a strange white place called "[[VideoGame/{{Portal 2}} Aperture Science Urban Zombie Testing Facility]]" which is filled with companion cubes, zombies and [[TheCakeIsALie cake]].
* EdgeGravity: 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.
* EverythingsBetterWithPlushies: Of the [[http://store.valvesoftware.com/product.php?i=S0205 tank]], [[http://store.valvesoftware.com/product.php?i=S0203 hunter]], and [[http://store.valvesoftware.com/product.php?i=S0201 boomer]]! Despite their hideous appearances in-game they make adorable plushies.
* GoneHorriblyRight: The result of Valve trying to squash the game breakers from the first game; melee shoving abuse and corner camping. The sequel added new special infected to discourage survivor players from corner camping and added running events where the survivors have to move in order to stop the event. However, this backfired greatly since most survivor players will now rush the entire time in every map and rarely stop, making it difficult for infected players in versus mode to land an attack on them.
* {{Gorn}}: The damage modeling borders this, even more than the first game. Torso wounds gape, expose bone and can spill out the zombie's guts, heads may be only halfway destroyed, pipe bombs exploding a mob of enemies went from the first game's [[PinkMist cloud of red]] to a shower of assorted body parts and intestines, and anything that catches fire will have a charred appearance by the time it stops burning.
* ItsPopularNowItSucks: Invoked and played with by the Midnight Riders. Near their last known concert site, a bunch of well-wishers and mourners lament the loss of the Midnight Riders... until a graffiti says they were safely airlifted out. Then the graffiti turns to angry "they sold out and were never good" insults.
* LeeroyJenkins: 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.
* [[{{LetsPlay}} Let's Play]]: Both games have one on the Something Awful forums, with the first [[http://lparchive.org/Left-4-Dead/ already archived]] and the second temporarily on hiatus.
* {{Machinima}}: Machinima/ProfoundMomentsInLeft4Dead2.
* MostFanficWritersAreGirls: [[HetIsEw Ellis]] and [[YaoiFangirl Nick]] is the standardized [[{{Shipping}} pairing]], truly.
* MythologyGag: [[VideoGame/{{Portal}} "Still Alive"]] can play on jukeboxes, albeit very rarely.
* OnlySixFaces: averted with a better common infected random generation system.
* OurZombiesAreDifferent: Of the infected, easily-enraged sort much like in ''Film/TwentyEightDaysLater'' and various types of {{Elite Zombie}}s.
* PreorderBonus: The baseball bat weapon, which spawned in the start of every single campaign and people who didn't preorder could still use the bat as long as a player on the team had preordered. When The Passing DLC was released, baseball bats now randomly spawn in the maps with other weapons instead of always being in the start.
* PoorCommunicationKills: 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.
* PreviousPlayerCharacterCameo: The main draw of ''The Passing''.
* SeriousBusiness: 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 TooDumbToLive 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. [[note]]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.[[/note]]
* SlidingScaleOfContinuity: The game is pretty firmly level 3 (Subtle Continuity), with the start of the next area being a direct result of what happened at the end of the last. For example: fueling up a race car to escape from a zombie infested mall only results in them abandoning the car when they reach blocked traffic, thus having to travel through a dilapidated carnival on foot.
* SuperPowerLottery: As far as zombies go, the Tank and Witch have won this.
* SuffersNewbiesPoorly: VS mode has a lot of these guys if you're new to the game mode. Teamwork is critically important and while you will get people who are forgiving of your mistakes, you'll get just as many people who want you gone. Naturally, you'll encounter less of these problems as your skills improve.
* TakeThat: In the 2nd map of The Passing, when approaching the stairwell leading into the sewers, there's a sign that says the rest of the underground tour will be finished in the year 2010. Rochelle or Coach may quip about how the first phase is nowhere near finished and wonder how there can be a phase 2 already. This is a jab at the fan base that cried out how ''Left 4 Dead'' wasn't finished when ''Left 4 Dead 2'' was announced.
* TheVirus: 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 [[Comicbook/IncredibleHulk Hulk]].
[[/folder]]

[[folder:Gameplay Tropes]]
* ArmorIsUseless: Averted by the riot cop zombies, who can endure anything other than explosions or fire; [[AttackItsWeakpoint so long as it strikes them in the front.]]
* ArtificialBrilliance: while the Special Infected can be quite stupid at times, it doesn't happen too often.
** Most of the times, they 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 and Spitters 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. Generally speaking, the Specials all try to get to places that the survivors can't reach easily before attacking or after being spotted.
** Tanks are now much smarter than in the prequel. They try to avoid fire the player makes, assuming the player sets the fire off too early. 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 occasionally 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.
** A simple matter, but AI survivors will [[NeverSplitTheParty usually pair up with them if two human players split up]].
* ArtificialStupidity: Although not too horrible, the Survivor AI has many infamous quirks. This is a great reason to play the game with actual people. See [[http://www.youtube.com/watch?v=VqyNS7ZdY1A this YouTube video]] as a hilariously shameful example from around release.
** The AI seems to have been improved since the first game, though some of the achievements cause it trouble. Of particular note is the "Sob Story" achievement, requiring the player to complete a stage without killing a Witch. The AI is not remotely suited to sneaking missions.
** The Chainsaw Massacre mutation amplifies the survivor bot's stupidity to new levels. They will either run ahead or lag badly behind and not do too well in saving you from special infected. This was corrected later causing the AI to rarely stray far from players, but they are still have issues.
** Survivor bots can't see through scenery and have a [[TheGuardsMustBeCrazy disturbingly short attention span]]. In versus mode, the survivor bots will [[NoObjectPermanence quickly forget]] about special infected if they so much as [[FailedASpotCheck crouch behind a car]].
** If a Jockey grabs on to you, the AI rarely, if ever, just shoots the Jockey. The tendency for computer-controlled Jockeys to [[TheComputerIsACheatingBastard randomly decide they can't be killed until they've at least done some damage to a survivor]] doesn't help.
*** A similar case also happens for Smokers. In the first game, the survivor bots would usually be really quick in saving someone caught by a Smoker. In the sequel, they now will sometimes ''wait'' until you take damage before they free you.
** It gets pretty close to SpitefulAI: survivor bots always place human players between themselves and their target so they can [[FriendlyFireproof shoot through the players and throw off their aim]], they [[FantasticRacism typically take forever to rescue humans from special infected but immediately drop everything if another survivor bot is in danger]], and if they manage to piss off a Witch they will once again place the player between them and said Witch, presumably in the hopes that it goes after the player instead.[[note]]The worst bit? Most of this was the result of a patch that actually ''upgraded'' the AI; previously they had been just TooDumbToLive.[[/note]]
** Whenever you encounter a Spitter, bots will make no attempt to avoid their acid until they've already stuck their feet in it.
** And lastly, Survivor Bots are specifically programmed not to mess with throwables like bile bombs, gas canisters and molotovs. This would probably be a blessing if not for the fact that that the two "Scavenge" finales involve [[FetchQuest collecting them]]... and [[TimedMission spawn higher densities of zombies if you take too long]].
* AuraVision: Used to find teammates as Survivors and used by Infected to find Survivors health and location.
** Averted in Realism Mode.
* BackStab: Shoving an idle common from behind is a OneHitKill.
* BadBoss: 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.
* BattleInTheRain: The ''Hard Rain'' and ''The Passing'' campaigns.
* BigDamnFireExit: Stage two of ''Dead Center''.
* BoomHeadshot: Played straight, to YourHeadAsplode levels with common infected.
** Mercilessly averted with the Tank, which receives the same damage from headshots as being shot anywhere else.
* BottomlessMagazines: The players must reload, but they've endless ammunition for their sidearms and supply caches provide infinite replenishment for your main weapons.
** Exaggerated in the ''Gib Fest'' Mutation gametype, which gives all four survivors [[MoreDakka an M60]] with infinite ammo.
* CallingYourAttacks: Played straight by survivors throwing grenades, invoked with the special infected's vocalizations giving them away.
* CameraPerspectiveSwitch: The game is mostly played in first person view, but the camera will switch to third person view when the player is doing an action or is pinned by a special infected.
* ChandlersLaw: The Director AI pulls this quite frequently: stay in one place too long instead of advancing and you'll get a bunch of Special Infected coming at you.
** It's also more likely to send a Zombie Horde at the Survivors at any given moment the slower they're progressing through the level. This can be something of a vicious cycle when playing on Expert.
* ChekhovsGun: In the first chapter of ''The Dark Carnival'' campaign, a jar of boomer bile will always spawn in the same spot. Almost no other jars spawn for the rest of the entire campaign. If you keep that jar till the end of the fourth chapter, it can be used to almost completely bypass an incredibly tough gauntlet right before that chapter's safe room.
* CherryTapping: It's possible to kill even the Special Infected, except tanks, witches, and chargers, just with the secondary melee attack. Just [[TooDumbToLive don't try it on the Boomer.]]
* {{Chiaroscuro}}: Actively exploited by the developers to guide the players, after they noticed playtesters' [[DarknessEqualsDeath tendency to move toward the brightly lit areas]].
* CriticalExistenceFailure:
** Averted with the survivors. When seriously injured, you run slower, jump lower. After taking pain pills, or having just been revived by a teammate, your health is constantly dropping, and at 1 [=HP=] you slow to a crawl. If your health gets taken all the way out and you're not on your "last down", you drop to the ground, only able to use pistols, and slowly bleed out until you die or are revived by an ally.
** Played straight with the common infected. Play long enough and you'll see a zombie run up to you that has had [[OnlyAFleshWound both of its arms shot off]]. (What does it plan to do then, bite you?)
** Even if one of them ''explodes'' after their life goes from 1 to 0, it's mostly Justified with the Special Infected, who obviously are extremely aggressive and have little-to-no self-preservation instinct left. Barring a few Specials who will duck behind a wall if they're not ready to attack you yet (before attacking you later instead, of course), they are ''going'' to come after you no matter what happens to them until ''one'' of you is dead.
* DamageSpongeBoss: Tanks, full stop. Four Survivors starting a level have a group total of 400 HP. On Normal difficulty, the Tank has ''4,000''.
* DaylightHorror: Daytime segments don't just change the lighting, but the behavior of one of the Special Infected. Witches normally sit in one place at night, but during the day they wander around.
* DeathCourse: The finale to ''The Parish'' differs from [[HoldTheLine the others]] tasks the survivors with racing across a bridge to a waiting military helicopter while fighting off continuously-spawning waves of zombies.
* DeathIsASlapOnTheWrist: Dying does not mean you are forever gone from the game. You will just respawn in a closet, come back in the next map, or get revived on the spot from a defibrillator. Versus and Realism mode prevents you from coming back until the next map and dying during a finale on any mode gets you KilledOffForReal.
* DeathIsCheap: You can be [[MagicalDefibrillator revived on the spot by a defibrillator]], rescued from a closet in campaign mode, or just simply respawn in the saferoom in the next chapter.
** The ''Ironman'' Mutation gametype attempts to avert this, but only removes saferoom respawns.
* DeathOrGloryAttack: Cr0wning the Witch.
* DifficultButAwesome:
** The grenade launcher can clear out hordes with one well placed shot, make most special infected stumble (making it great to free pinned survivors without worrying about accuracy), and a direct hit to the Witch can make her stumble and buy you time to get away or kill her quickly. The difficulty in using the weapon is you have to reload after every shot (and each reload takes about 4 seconds) and you can't get more ammo for the grenade launcher. Unless you are skilled enough, you may cause lots of friendly fire damage to yourself or the team. You will be using your pistols or melee weapons a lot to make up for the grenade launcher's weaknesses.
** It is entirely possible to counter every single Special Infected's pinning attack (smoker's tongue, hunter's pounce, Jockey's riding, etc) with a well placed shove, shot or slice. However, the window for you to perform these actions are measured in ''a fraction of a second'', but it feels completely awesome to do so.
** The Tonfa is the fastest melee weapon out of the entire melee weapon set. It swings very fast, but it has an extremely short reach and swing arc, which makes it difficult to consistently hit zombies that are swarming you.
* DifficultySpike: 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, [[OhCrap 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 [[OneHitKill flat out kill you]].
* [[TheComputerIsACheatingBastard 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 accuracy, and cannot directly cause friendly fire(being able to literally shoot through others). [[JustifiedTrope 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.
** ''[=L4D2=]'' has been accused of adding a degree of FakeDifficulty by multiple special infected spawns in campaign modes, but these are glitches... The [[{{HarderThanHard}} Hard Eight]] Mutation notwithstanding.
** AI Tank rocks, affectionately called "rofl rocks" can [[http://www.youtube.com/watch?v=FkmAna8Tg5c#t=3m31s clip through some geometry]] in order to reach a player.
** 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 [[{{GameOver}} fun times]]. In versus, where the specials are human-controlled, you cannot spawn in the ending safe room.
* EnemySummoner: The [[MonsterClown zombies dressed as clowns]], in addition to the Boomers.
* EscortMission: Played with with the "Guardin' Gnome" achievement, which is earned by winning the garden gnome from the shooting gallery in ''Dark Carnival'' and carrying it through the rest of the campaign and onto the rescue chopper.
* ExplodingBarrels: Gas cans, propane tanks, oxygen tanks, boxes of fireworks, and actual barrels in ''the Sacrifice'' campaign.
* FallingIntoTheCockpit: 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.
* FakeDifficulty: The Hard Eight and Special Delivery mutations spawn Special Infected at an increased rate, which is a good challenge for players who know how to deal with each Special and move along. Unfortunately, Spitters tend to be spammed, especially in tight spots, which forces you to either run through its acid or wait it out (a terrible idea with the constant stream of powerful zombies). And if you do the latter, chances are another one will spawn ''immediately'' after it dissipates.
* FetchQuest: The Streets chapter of ''Dead Center'' require the survivors carry a sixpack of cola, carrying the gnome to the helicopter in ''Dark Carnival'' gives players an achievement, and there have been a few Mutation gametypes requiring the gnome.
* GameMod: From adding extra custom campaigns to correcting scripts like bot behavior or gun realism, and including changing the flashlight's texture so that it becomes useful [[RuleOfFunny or funny]], these were add-ons were always popular in the game. The Workshop update made them even more so due to the ease to install and manage them.
* GenreSavvy: Nick asks the group, after they reach the hotel elevator in Dead Center, if anyone has been bitten.
--> '''Nick:''' Did anyone get bit? Isn't this how this works?
** WrongGenreSavvy: The survivors are immune, the disease is airborne, and quite frankly there's a pretty low chance of them ''not'' getting bitten anyway.
* GoombaStomp: Jumping on a common or uncommon 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.
* GravityBarrier: 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. The most common type of griefer are players that shoot their own teammates to death, which is ''extremely'' common on Expert difficulty games due to the sheer friendly fire damage.
** Playing as the infected is basically griefing the survivors ''[[RuleOfFun as the goal of the game.]]'' The griefers are getting their kicks from the game itself most of the time!
** The ''Room for One'' Mutation gametype defies the normal logic of the game by only allowing one survivor to escape and encouraging team killing.
* HarderThanHard: Expert mode is ExactlyWhatItSaysOnTheTin. Only experts can expect to survive.
** Realism mode is a setting independent of the standard difficulty settings. This mode removes all the auras allowing you to locate other survivors, items, and infected which are pummeling other survivors. Commons take less damage when shot anywhere except the head, and survivors only respawn at [[{{Checkpoint}} Safe Rooms]]. It can also be set to [[NintendoHard Expert mode,]] which gives you an [[BraggingRightsReward achievement]] if you manage to survive. One odd quirk of the mode: the magnum still instantly kills ordinary infected with body shots, which greatly increases its value; an early magnum can make a big difference in survivability.
** Apparently, Realism mode will be nothing compared to Ultra Realism [[http://left4dead.wikia.com/wiki/Mutations#Unrevealed_Mutations Mode]]
* HealthDamageAsymmetry: Each of the survivors has up to 100 health. Besides [[ActionBomb The Boomer]] and [[ColdSniper The Spitter]], all special infected have at least twice as much, with the tank starting out with at least 4,000, yet the survivors can pick off special infected with a few shots of the right gun, and special infected do damage slowly over time. Subverted on [[HarderThanHard Expert mode]], when it's just the damage that is symmetrical. They will happily kill you off if your team mates are distracted.
* HellIsThatNoise: Every single type of Infected has their own distinct sound/musical cue to warn you of their arrival, including a few who will switch from low growls to all-out screams or roars as soon as it has one of the Survivors in its line of sight. Because the Survivors can be overrun very quickly on just about any difficulty if they aren't being attentive enough, listening for them is so essential that you almost can't play it without the sound up reasonably high (which doesn't help a whole lot with the [[JumpScare Jump Scares]]).
* HesJustHiding: 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. [[invoked]]
** Averted in the final chapter of each campaign after the rescue vehicle has been summoned. Dying means you get KilledOffForReal.
* HitAndRunTactics: This is usually the best way to deal with the Tank, by [[KillItWithFire 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.
* HitboxDissonance: Hitboxes for hunters and jockeys 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. Compounded further by how little time there is to stop a jockey pounce.
** This game somehow just has inferior collision detection. It isn't common, but it certainly isn't rare to hear the impact and see blood fly from a zombie you just smacked in the face with a [[{{OneHitKill}} crowbar]] just ignore it and continue anyways...Even when playing offline where lag couldn't account for it.
* HoldTheLine: Occurs in all crescendos and finales(except a couple in the Parish) as well as survival mode.
* HyperAwareness: 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 LazyBackup with a horrific case of SelectiveObliviousness.
* InterfaceScrew: Your vision becomes [[DeliberatelyMonochrome monochrome]] with red halos for items if you're incapped twice without using a medkit.
** A variation also occurs with a lightning storm in The Swamp. When the storm is passing overhead, players' microphones are automatically quieted, to the point the players will literally have to shout to be heard by their teammates.
* InvisibleWall: Only the Infected in Versus mode will run into them, and if you get close enough they stop being invisible... instead they become labeled "[[CaptainObvious wrong way!]]"
* ItCanThink: 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.
* ItsQuietTooQuiet: In Last Man On Earth, not only does your survivor continually [[GoMadFromTheIsolation talk as if the other survivors are still there,]] they occasionally shout out something along the lines of "Hello?" or "Is anyone out there?".
** There is also a lack of Common Infected, which makes the gameplay overall much quieter, but also gives the eerie feeling that something else is going on...
* JustForPun: Every achievement.
* KillerGameMaster: The AI director. Particularly on Expert mode, when he stops even ''pretending'' he doesn't hate your guts.
** In ''Left 4 Dead 2'', there are some maps where the infected charge out of the safe room, or very close to it. However, the director will stop the attacks when all four players are in the room but with the door still open (but existing infected will still charge).
* LevelInReverse: The campaign Hard Rain has the second half be the levels of the first, played backwards and with a monsoon in full effect, obscuring vision and dialogue.
* LimitedLoadout: You can carry one primary weapon (generally rifles and shotguns) from a selection, one secondary weapon (either a set of unlimited ammo duel pistols or a melee weapon or a Desert Eagle) and one equipment item of each type (only one thrown explosive such as a pipe bomb or a molatov, choosing between a medkit and a defibrillator, etc...)
* TheLoad: competely aside from the issue of bad players, any time you engage in an EscortMission, the party is reduced to three members as the person carrying TheLoad cannot use their weapons. (Gnome Chompsky can be used [[ImprobableWeaponUser as a lethal weapon]], but it requires [[BackStab very opportune movement]], or a ''lot'' of shoves.)
* LuckBasedMission: 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.
* LudicrousGibs: [[BadExportForYou Provided you don't live in Germany or Australia]].
* MadeOfPlasticine: Because of how melee weapons work, it's entirely possible, and really easy, to carve through a ZergRush with, let's say, a [[http://en.wikipedia.org/wiki/Baton_(law_enforcement) baton]]. Also, hitting a special infected with a [[FryingPanOfDoom frying pan]] will kill them in one hit, except for the Charger, who takes two hits, and the witch/tank, who are MadeOfIron.
* MagicalDefibrillator: Capable of bringing players back from the dead.
* MajorInjuryUnderreaction: A survivor's typical response to friendly fire? Some variant on "Stop shooting me!"
* MiniGame: "Dark Carnival" has 3 games for you to play, which are the Shooting Gallery, Test Your Strength, and Whack-A-Mole with the park's mascot! They each are tied to an achievement as well. [[spoiler: They also alert a horde of zombies if you successfully complete any one of them.]]
* MookChivalry: The "Last Man on Earth" mutation makes it so that Special Infected (who's clutches you would normally need a teammate to escape) back off once they've taken off your first health bar. They're not as kind the second time around, however.
** Jockeys and Hunters may sometimes decide to stay where they are and slash you the second you get up, which may cause death due to your health being so low after getting self revived.
* MusclesAreMeaningless: 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.
* MyRulesAreNotYourRules: 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.
* NeverSplitTheParty: The game is '''built''' on this trope. Get separated or lose track of your teammates and YouAreAlreadyDead.
** 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 PointOfNoReturn and ''cannot'' go back and help your teammates. This just reinforces the original lesson, since you are forced to soldier on short-handed.
** This spawned the meme of Karma Charger, where a random Charger would come and pounce on you if you ever leave the main group. Fittingly, the AI director prioritizes lone wolves who ditch their friends, and would actually spawn a Hunter to deal with them. Of course, this lead to players finding ways to singlehandedly counter said "karma".
* {{Nerf}}: In the original, players could "shiva stack" (wait in a corner or secluded room, all bunched up, and repeatedly melee). This made it nigh-on impossible to extricate them with anything other than a tank. ''Left 4 Dead 2'' stopped stacking with the introduction of the Charger and the Spitter.
** Melee weapon damage to Tanks has been nerfed. Damage is now 5% per hit instead of 10%, which means now that survivors will most likely have to resort to kiting now instead of everyone running up to a Tank and smashing him with four Frying Pans Of Doom.
** And the shove motion ''itself'' 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.
** Also, auto-spawning in Versus finales being removed made it more enjoyable for the infected team and more difficult for the survivor team.
* MoodWhiplash: Happens quite often, thanks to the automatic in-game dialogue.
--> '''Ellis:''' ...Y'all... Y'all, I'm hurt.... Look, guys, ''KIDDIELAND!''
* NietzscheWannabe: A lot of the graffiti is this. It gets [[DeadpanSnarker shot down]] by both the cast and other graffiti.
* NintendoHard: Many Mutation gametypes.
** Hard Eight causes eight special infected to spawn at once.
** Special Delivery eliminates common infected but [[HarderThanHard ensures a full set of]] '''''[[HarderThanHard TEN]]''''' [[HarderThanHard special infected at all times.]]
** Lone Gunman takes it UpToEleven by surpassing Expert damage even on Eas y(ANY damage at all is game over on Expert Lone Gunman), allowing only one survivor armed with only a magnum and grenades, and spawning Boomers constantly.
** [=TAAAAAAAAAAAAAAAANNNK!!!=] plays it for fun, by removing AI-controlled special infected and having players only be survivors or Tanks. This can actually make the game much easier, as survivors can [[LeeroyJenkins just run like hell through the level]] without having to worry about being grabbed by a special.
** Obtaining the "Strength In Numbers" achievement. To earn this, you have play Team VS or Team Scavenge with a group of your friends and beat the other team who are random players that are friends with each other. The catch? There will always be one team who will all RageQuit and screw over the other team out of earning the achievement. On top of this, Team VS/Scavenge is hardly used at all since most people prefer public games where it is easier to set up and get a game going more quickly. With rage quitting and people not playing these game modes, the achievement is pretty much unobtainable without boosting.
* NoFEMAResponse: [[NoCelebritiesWereHarmed 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.
* NonStandardGameOver: During The Sacrifice's finale, if three of the survivors are killed, the level ends in a failure and you have to restart since you need at least two people alive for the final part since one person has to sacrifice themselves to restart the bridge and the other person has to be alive so they can escape.
* NothingIsScarier: hearing a sobbing Witch and knowing she's close and you have to be careful or you'll startle her and she'll screech and try to rip you apart - and sometimes you just don't find her...
** This is even more scary in the infamous Hard Rain campaign. It isn't bad enough to have 20 witches, it isn't bad enough to have them walk around, it isn't bad enough that all but three of the Special Infected can push you into one (and will appear absolutely out of nowhere), and it also isn't bad enough to have to fight tanks during this, but they also had to throw in the sugar cane fields (where your vision is reduced to about 2 feet in front of you).
*** And then it gets even worse on the way back through! Whenever the storming starts up, all the witches in the area will HOWL IN RAGE yet the odds of you actually running into one are pretty low. This continues right up until the finale, and you can never tell if that howl is on the other end of the level or just around that corner...
*** It doesn't help that the sounds made by the storm can resemble startled witches.
** Forget Witches, sometimes you hear a special infected or its musical cue long before you see it or you know it's around the corner but don't want to be the guinea pig. The worse still, is when the Tank music starts playing but takes its time finding you so players are left frantically trying to spot it whilst trying to stick together or rethink their plans.
** The worst scares you can get in Left 4 Dead 2 is in the mutation The Last Man On Earth, where it's single-player with no bots, and no common infected. It can get very eerie walking through the level alone while hearing the growls of special infected sneaking up on you, and since you're alone they are far deadlier.
*** What's even worse than that is the fact that the single character's vocal script is unchanged, meaning that they talk to thin air - even taking to specific survivors ''who aren't there anymore''.
* ObviousRulePatch: VS mode's scoring was altered to be more close and fair between teams. Left 4 Dead had scoring be sorely based on who made it to the safe room plus a multiplier and if a team got killed beforehand, their score would be a lot lower. Left 4 Dead 2 has the score be purely on distance traveled so that you still had a chance of catching up if you didn't make it to the safe room.
** Explosive ammo was removed from VS mode after some time due how easily survivors could stop attacks from the infected players with it. Defibrillators were also given a 25 point penalty for its use in VS mode so survivors are punished for having a teammate brought back to life in a way.
* ParachuteInATree: Corpses of paratroopers hanging from trees are frequently found. Upgraded weapons can be found on their bodies.
* PrettyLittleHeadshots: Headshots on witches remain effective but lack the gruesome aftermath and OneHitKill. Unless you cr0wn one with a shotgun.]]
** Headshots with Tier One weapons leave the head intact.
* RandomlyDrops: Hazmat uncommons (Dead Center and the Sacrifice) with bile jars, riot cop uncommons (the Parish) with tonfas, and fallen survivors (the Passing) with random items.
** During the holiday season, gift boxes were randomly dropped by special infected in VS mode, linked to an achievement and a Steam sale raffle.
* RegeneratingHealth: Inverted trope. Pills, adrenaline 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.
** Played straight with the Healing Gnome mutation. All health related items are removed from the maps and the only way to heal is to hold a special gnome that regenerates health as long as you hold it. Of course, this also reduces the amount of firepower the team has.
* RespawningEnemies: All infected excluding the Witch and Tank.
* ScriptedEvent: Generally not used, but there are a few such as [[spoiler: the military bombing a bridge.]]
* SelfImposedChallenge: Several have achievements for them. No examples, please.
** Lampshaded with the two Expert-related Achievements: What Are You Trying To Prove? and Still Something To Prove. Both you get for completing all of the Maps shipped with the game, on expert.
* SequelDifficultySpike: ''2'' has many more spawn points for hordes, discourages camping, it's new special infected are even designed to punish survivors that stay ''too close'' to each other, rolling crescendos are much more challenging than the regular ones, and Realism adds another level of challenge even to the Expert difficulty.
** Several Mutation gametypes take this UpToEleven.
** ''The Passing'' and ''The Sacrifice'' DLC campaigns are '''much''' harder than others in spite of being shorter.
** And in most every campaign that has been ported over from ''1'' to ''2'', there are alterations to increase difficulty. In some cases this is simply to adjust for the new gameplay elements, but they overdo it in some instances.
*** Most notably in the Terminal of Dead Air, what was once a panic event was upgraded to a Rolling Crescendo. However, the developers did not remove the normal crescendo event at the beginning of the level, resulting in this one having two crescendos, with one being one of the hardest in the game (you have to cover a lot of ground unlike in Dark Carnival).
* SoundCodedForYourConvenience: 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; especially for players using surround sound.
* SpeedRun: How some players play Versus mode as survivors.
* StandardFPSGuns: [[BottomlessMagazines Pistols, magnums (albeit played much differently than normal)]], shotguns, assault rifles, mounted machine guns, sniper rifles, grenades, and melee weapons.
* SuperDrowningSkills: Any map that has a river in it. Unlike the first game where being underwater too long would drain your health eventually, being submerged will instantly kill you.
** The only exception is when the water is knee-height, and getting incapacitated puts you below the surface. After a moment, however, you start taking a reasonably large amount of extra damage (aside from the automatic bleed-out damage) until you either begin to get picked up, or you die.
*** Also applies when crouched underneath the water in the finale area of Death Toll (originally from the first game).
** The water in ''Left 4 Dead 2'' is so fetid that it will kill an infected that's ''in ghost mode.'' Causing their corpse to pop out of thin air, natch!
* TakeUpMySword: If a survivor dies, another can take their gun.
** Or this might well be [[ExactlyWhatItSaysOnTheTin an actual katana.]]
** During The Passing, you also find an assault rifle in the hands of [[spoiler: a deceased Bill.]] You can pick it up and finish the job that they started.
* TakingYouWithMe: At certain points, a well-aimed Charger can grab a survivor and bring them both careening to instant death.
* TheLastManHeardAKnock: Although you're the only Survivor in Last Man On Earth, there are still rescue vehicle pilots and the gun store owner.
* ThingsThatGoBumpInTheNight: The Special Infected warning sounds. Especially so in Last Man On Earth.
* TotalPartyKill: "Hey guys! [[{{Leeroy Jenkins}} Check out my grenade launcher!]]"
** A few specials can cause this singlehandedly: tanks (natch), chargers, and (if your team is [[TooDumbToLive spectacularly incompetent]]) hunters.
** Averted with the Witch, who is programmed specifically to only be aggressive towards one Survivor. Not that things don't go OffTheRails anyway.
* UniqueEnemy: Each campaign in [=L4D2=] has an "Uncommon Infected" unique to it:
** ''Dead Center'' has infected CEDA workers, whose Hazmat suits render them impervious to flames. There is also a zombified Jimmy Gibbs, Jr., who is also immune to flame, can obscure vision with motor oil, and won't be sidetracked by pipe bombs or Boomer bile.
** ''The Passing'' the Fallen Survivor, an infected man in militia gear who [[MetalSlime will run when attacked, has high health, is impervious to flames, and drops valuable items on death]]. There is also a Witch in a bridal dress.
** ''Dark Carnival'' has infected clowns, whose squeaky shoes attract more zombies.
** ''Swamp Fever'' has "Mud Men", who can move more quickly then other zombies and can obscure your vision with mud.
** ''Hard Rain'' has infected sugar mill workers, whose ear protection gear prevent them from being lured to pipe bombs, and whose hard hats make them more resilient to melee weapons.
** ''The Parish'' has infected riot cops, whose body armor makes them invincible to all attacks from the front.
* UnusableEnemyEquipment: {{Lampshaded}} by Coach when he sees the Riot gear-wearing Zombies.
-->'''Coach''': "That zombie's got armor.." [{{beat}}] "'''I''' want armor!!"
** Inverted in that some uncommon do carry usable equipment, but ([[CaptainObvious being zombies]]) never actually use it.
* UnwinnableByMistake: There's a bug in the collision detection of the rescue boat that ends ''Swamp Fever'' and ''Hard Rain''; depending on where your character is standing, this can result in them drowning as it sails out from under them. It is both [[HopeSpot depressing]] and [[YouHaveGotToBeKiddingMe hilarious]] to be {{boatmurdered}} in this way.
* VideoGameCrueltyPotential: There is just something so fun about jumping on top of a lone survivor as a Hunter, laughing in delight as you tear them apart, knowing they're completely and utterly helpless.
** The VS mode is based around being as cruel as possible, as it actively encourages you to take notes during your own Survivor playthrough and consider when is the worst possible time for your particular special infected to appear, and to use it when it's your turn to be the zombies.
* VideogameSetpiece: The explosions in The Parish.
* ViolationOfCommonSense: 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, '''TRUE''' survivors don't even 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 the 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}}.
** Melee weapons always do 5% of a Tank's maximum health per hit (meaning 20 melee hits will kill them). This doesn't amount to much on lower difficulties, but it's certainly a lot of HP on higher ones. [[CaptainObvious Obviously]], trying to get close to a Tank when it can instantly incapacitate you [[TooDumbToLive is usually a bad idea]], but being able to deal about 1,000 damage in 2 seconds without using ammo is something worth noting.
* WeCannotGoOnWithoutYou: If there are any bots on the team in any non-Versus mode, you'll have to start the level all 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. Fortunately, there are {{Game Mod}}s that fix this.
* WhatTheHellPlayer: Shoot one of your fellow survivors, and they'll call you out for it with scripted responses.
** Or trigger a few car alarms in the impound lot in ''the Parish'':
-->'''Coach''': ''WILL YOU STOP SHOOTING THE GODDAMN CARS!?''
* YouHaveOutlivedYourUsefulness: 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.
** 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.
* YourHeadAsplode: Shots to the head of regular zombies with primary weapons leave only their neck and a PinkMist.
* YouALLLookFamiliar: The basic infected actually have [[OnlySixFaces 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 and some of the Bosses have two models in the second game (the boomer has a female version, the Witch gets a one off version wearing a wedding dress in the final campaign), but only one in the first.
* ZergRush: 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 accidently set off a car alarm, [[WebAnimation/ZeroPunctuation or whenever he's bored, which is]] ''[[WebAnimation/ZeroPunctuation all the time]]''. The normal infected also like to rush pipe bombs because of the smoke detector alarms rigged to them, and Boomer bile (both regular and purified) for obvious reasons. It is also possible to use a bile jar on a Tank, and there is an achievement for it.
[[/folder]]

[[folder:Weapons Tropes]]
* AbnormalAmmo: Frag or incendiary ammo boxes, which provide one magazine of this before switching back to regular rounds.
* AKA47: As with the second game, though a few guns, both old and new, are now referred to by their real names.
* AnAxeToGrind: One of the most common melee weapons is, understandably, the ubiquitous fire axe.
* AwesomeButImpractical: The minigun and mounted M2 machine gun, which can shred oncoming hordes and tanks like no other, are never positioned so they can effectively cover more than two of the generally five or so directions that zombies can come from in official maps. Additionally, the M2 is almost impossibly rare in comparison to the previous game's minigun, only showing up in two finales out of six.
** The [=M79=] grenade launcher, which requires much practice to use effectively that is, kill as many infected as possible without blowing your own team up in the process.
* BatterUp: Among the melee weapons, there are baseball bats and cricket bats. Sometimes a survivor will say this when they grab one.
* BottomlessMagazines: For gameplay reasons, sidearms have infinite ammunition. They don't do as much damage as primary weapons and they share a slot with melee weapons, which don't have any limit either [[ChainsawGood with one exception]]. Also, they're the only weapons you can use while incapacitated and if you're holding any melee weapons, you'll temporarily get one basic pistol until you're back up again.
** Two mutations also employ this: "Chainsaw Massacre" gives the survivors infinite-fuel chainsaws, and "Gib Fest" gives them infinite-ammo M60s.
** It is possible for Gib Fest games to glitch and spawn any weapon normally. Extremely rarely, it is possible to find a Grenade Launcher. Because of the one-shot nature of the thing in normal gameplay, anyone who finds one in Gib Fest will quickly notice it ''has no firing cooldown'' [[note]]The weapon's long reload was meant to be it's cooldown, meaning once Gib Fest removed it's reload requirement your rate of fire is only limited by how fast the script replaces your ammo[[/note]]. Much hilarity ensues.
* ChainsawGood: The chainsaw has peerless damage dealing abilities, but has a fairly long starting time, only 60 seconds of "fuel", provides 50% damage resistance to common infected, and is replaced with a single pistol when it runs out of fuel or the user is incapped. The ''Chainsaw Massacre'' mutation is all about chainsaws: the only weapons that spawn are four chainsaws in the saferooms. They happen to have [[RuleOfFun unlimited fuel]].
* FryingPanOfDoom: One of the weapons with the fastest swing rate.
* GatlingGood: 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.
* GolfClubbing: And it has the same attributes as the {{Katana|sAreJustBetter}} to boot.
* GrenadeLauncher: The M79.
* GunsAkimbo: All characters can find and dual wield a second 9mm pistol for extra ammunition in the magazines.
* HyperspaceArsenal: Generally averted, except for one peculiar instance. If a survivor drops their handgun for a melee weapon, they will produce another handgun when they are incapacitated, which disappears as soon as they are hauled back onto their feet.
* IncrediblyObviousBomb: The pipe bomb is one, but with good reason - its red light and high-pitched squeal [[SchmuckBait attracts the standard infected]], making it less a question of where to throw them and more a question of ''when''.
* InstrumentOfMurder: Guitars as melee weapons.
* KatanasAreJustBetter: Played with. Damage-wise, Katanas in the game aren't any better than other melee weapons due to all melee weapons doing the same amount of damage to zombies. The advantages the katana has, however, is long reach and medium swing speed. The "Four Swordsmen" mutation is all about these, being the only weapon available.
* KillItWithFire: Molotov cocktails, gas cans, and incendiary ammo packs. Very useful against Tanks and Witches, as not only does it deal continuous damage until death (or the Tank wades into a body of water), it slows them down[[note]]A Witch will only run as fast as a healthy Survivor, and a Tank slows down to an injured Survivor's pace[[/note]].
* LudicrousGibs: Pipe bombs, the M60 and explosive ammo produce this from common infected in ''2.''
** The "Gib Fest" mutation [[UpToEleven amps it up to extremes]] by only having weapons that cause this. Namely, the M60. With a Magnum for when you're incapacitated or when you want a little more precision.
* MacheteMayhem: Now go pretend you're [[Franchise/FridayThe13th Jason Voorhees]] fighting zombies.
* MolotovCocktail: Practically a staple of the series, and essential to block off an infected access route.
* MoreDakka: [[{{BFG}} The M60.]]
* TheMusketeer: It's possible to have a melee weapon as reserve.
* RangedEmergencyWeapon: Pistols.
* RareGuns: The Desert "Cobra", SPAS-12 and SCAR-L in ''Left 4 Dead 2''. The starting pistol, a SIG Sauer P220, is also stated in the commentary to be extensively customized[[note]]overall a P220 with the barrel and slide of the compact P228, and a custom two-tone finish[[/note]], as is the Glock.
* ShootingGallery: In ''Left 4 Dead 2'''s "Dark Carnival" campaign, you can stop to participate in a shooting gallery whose prize is a lawn gnome; carrying the gnome through the end of the campaign nets you an achievement.
* ShortRangeShotgun: Averted. The shotgun's a viable weapon choice, even at a reasonable distance.
* SticksToTheBack: Every weapon and inventory item except pistols (they get holsters), pills/adrenaline, and grenades, which all go on the survivor's belt.
[[/folder]]
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->''The survivors have escaped!''