Abnormal Ammo: The Buzzsaw Bow and the Flare Revolver, two DLC weapons, are respectively a crossbow that shoots circular sawblades and a big revolver that shoots flares. Halloween 2013 DLC added a leafblower that sprays acidic Bloat bile and an apparently scratch-built weapon that launches exploding harpoons.
Actually a Doombot: Transit (Objective Mode) confirms without a shadow of a doubt that Patriarch has been cloning himself as well.
A.K.A.-47: Zig-zagged. There are things like the AA12, SCARMK17, MP5 and M4, and at the same time there's the "Handcannon" (a Desert Eagle), "Bullpup" (an L22), "Schneidzekk" (a Kriss Vector SMG) and "Combat Shotgun" (a Benelli M4). Also, similar to Left 4 Dead 2, the game's "AK47" is actually a Draco AK-pistol, modified with an unused AIMS-style folding stock. Of note is the promotional image for the Golden Handcannon(s), which refers to it/them by the Desert Eagle name.
And with the next two Summer Sideshows events we now have Hellride and the Steam Punk themed Steamland maps.
An Axe to Grind: One of the melee weapons is a fireaxe. Following the Twisted Christmas Event, completing an achievement in another game unlocks a dwarven battle axe.
Apocalyptic Log: A lot of the level descriptions are this, explaining what happened for the area to be overrun by specimens. Mostly this revolves around the specimens moving into an area, then slaughtering everyone within it with the team being sent to clean up or try to Hold the Line. Others mention the aftermath of your team's helicopter going down in an infested area, with specimens closing in on you.
Arm Cannon: The Patriarch's preferred method of problem removal, and the primary weapon of the Husk.
And with the Twisted Christmas 2011 update, you can use the Husk's arm cannon as a weapon yourself!
Some maps, especially Suburbia, which takes place in a small American town thousands of miles from the Horzine labs.
Since the specimens have no way of infecting others, this means that hundreds of them somehow crossed the Atlantic Ocean.
This becomes even more confusing when the Patriarch appears, since it essentially means that all of the specimens somehow crossed the ocean.
The map Icebreaker, taking place on a large cargo ship, could technically explain this, however.
Artificial Brilliance: Specimens will actively move to avoid hand grenades. Husks aim their shots to impact the ground near their target, similar to a human player with a rocket launcher. And, in an example verging on Artificial Stupidity, specimens will sometimes jump for the hell of it, just to throw off a player's aim. And speaking of behavior that's situationally stupid, most of the specimens seem to avoid approaching players in a straight line if they're already part of a large group so they can flank better.
Artificial Stupidity: Pathing for the specimens can make them suddenly change their mind about what direction to run when chasing players. This has been abused to make the Patriarch attempt to run and heal by trying to blow up a welded door in the same room as the players unloading into him. Bonus points if the door he came through is still open, moreso if he had only just passed it before attempting to run and heal.
Speaking of pathing, the floating light that leads players to the trader likes to spin around like a drunk instead of pointing players in the correct direction if they don't stop moving for a second to let it get its bearings. And in extreme cases, it may point players towards a path that leads to them hurting or even killing themselves if they follow it, such as skipping a set of stairs entirely by jumping over the side or pointing towards an open window on the third story of a building.
Ascended Fanfic: Numerous well-made custom maps and at least one pack of custom weapons have been officially added to the game through patches.
Ascended Meme: One of the Circus Scrake's lines is "And not a single fuck was given that day".
The inclusion of a Loadsamoney Expy named Harold Lott, who leaves a trail of money behind him as he walks. He also costs $5 by himself, compared to all of the other character DLC which are $2 for a pack of 4.
Ax-Crazy: The Specimens aren't so much as dumb as they are bloody insane. The Siren (in the original mod) acted as if nothing was wrong and everything was sunshine and roses and was wondering why the nice young men were hurting her, the Scrake was meant to be a medic and would feel good while healing people, but found that braining blokes felt even better.
Awesome, but Impractical: The Berserker perk can turn into this in later waves or later difficulties - being up close and personal with that many enemies, in particular that many Fleshpouds and Sirens, gets you killed very quickly.
On the other hand, expert Berserker players can easily run circles around most Zeds, and survive without any backup even on the highest difficulties.
Being able to stun many specimens with melee attacks definitely helps... unless your teammates interrupt the effect with their firearms.
Unfortunately, the Berserker also has the side-effect of blocking the lines of fire for the other players.
Going Guns Akimbo often has this effect, in that you have to sacrifice precise aiming for doubled firing rate and ammo capacity.
The MP7M and the M7A3 are both almost useless to anyone who isn't a Medic. The MP7 has light damage, a small mag size of 20, and an extremely slow heal dart recharge rate. While the damage for the M7A3 is much better, it weighs 6 blocks, has a small mag size of 15, and has the same heal dart recharge of the MP7. By contrast, the MP5M and the Schneidzekk are much better off perk, due to their heal darts recharging much faster.
However, the MP7M can be pushed to Difficult but Awesome by a skilled player, particularly a Sharpshooter that wants some full-auto teeth. Careful trigger discipline can compensate somewhat for the absolutely absurd fire rate and Boom, Headshot lower-end Specimens while saving the more expensive ammo of the Sharpshooter's dedicated weapons for real threats. While hideously expensive to non-Medics, the MP7 can be bought after the first round by a level 5 Medic (a level 6 Medic spawns with one).
The M7A3 and Schneidzekk also can venture into this territory. The former has damage similar to the MP5M while being fifty percent more expensive, and lacks the power to really go toe-to-toe with heavier-grade Zeds. It also has absolutely absurd recoil, making it difficult to hit anything on full-auto when waves get hairy. The Schneidzekk, on the other hand, has great damage, but a fire rate that borders on unbelievable and regular iron sights that block half the view when aiming, compared to the other weapons' more open sights. It also goes for a hefty price even when well-leveled.
The Combat Shotgun does the same damage per shot as the regular Shotgun, but is semi-auto instead of pump action, carries less shells, reloads slower, and costs more, which makes it better for taking down Scrakes and Fleshpounds than weak Zeds. While carrying 6 shells as opposed to 8 isn't much of a problem, the other two downsides are a bit extreme. Each shell reloads 35% slower, and it costs five times as much as the basic Shotgun.
The FAL. Boasts the exact same damage per shot as the SCAR (save a bit more range), with the same ammo capacity and with a higher fire rate, but costs £300-400 more and has a slightly longer reload.
The M99 AMR, in the hands of a high-leveled sharpshooter, can one-shot most enemies - including Fleshpounds! - at almost any difficulty level and go through a line of specimens like a hot knife. The downsides? It costs £6250 to fill up - but only holds 30 shots in reserve - making each shot cost £250. It's also a single-shot rifle with a reload time of at least 1.75 seconds, but the worst part is that it weighs 13 blocks - meaning that the only weapons you can carry alongside it is your starting pistol, knife and grenades (taking up a block in itself), and either a machete (a step up from the knife) or a pipebomb, neither useful for a sharpshooter. It's only useful against the Patriarch - money serves no purpose after the wave, and a capable sharpshooter can take out the rest of the specimens in that wave with their 9mm.
The Fleshpound does not appreciate being shot or having a line of sight on targets and not attacking them. It also doesn't appreciate it when it can't reach its target. Blood will rain like mist as it rips apart anything around it in a frustrated fury should a player find a spot it can't reach. This makes it difficult to earn cash since the player does not get money for specimens the Fleshpound kills.
This is actually a great way to win a round if you team is likely to die: if one person can glitch to an unreachable spot (and take out any Husks that approach) the Fleshpounds will basically act as a Mole, leaving only a few Specimens left to deal with.
Bored specimens will turn on each other, but very rarely.
The Berserker: The Berserker perk. With his brisk movement speed, absurdly thick skin and mighty swinging arm, he specializes in closing in on the Specimens and fighting at spitting distance, first with the humble knife or machete. Later, with some more dosh, he can keep up his nimble ways of dancing in and out of enemy range with renewed strength thanks to the fire axe, katana, or claymore, or become the world's most painful doorstop with a bloody awesome chainsaw.
On the specimen side, Scrakes, who swing wildly at a target with their highly-damaging chainsaws; and Fleshpounds, Scrakes on crack, who move slowly at first (but go into an unstoppable charge when sufficiently damaged), are capable of reducing players to mulch in a few hits.
Big Sodding Gun: Usually said while equipping one of the heavy weapons like the LAW and the M99, but as of the 2012 Winter Event, the Zed Eradication Device (Z.E.D.) which fires lasers and can emit a field which significantly slows down and lowers the defense of any specimens caught within it. The catch is that you need to collect all fifteen parts of the weapon scattered around the "Moonbase" event map in order to use it, and even then it costs 2,000 pounds and, like the other heavy weapons, weighs a lot.
Bling Bling Bang: One of the DLC packs released for the 2012 Christmas event allows players access to a gold-plated AK47, Combat Shotgun, M79 (complete with golden grenades), and Katana. A second pack for the 2013 Summer event adds the gold-plated Handcannon (with tiger-stripe pattern), AA-12, Flamethrower, and Chainsaw. The concept was then deliberately avoided for the 2013 Halloween event, with a new weapon skin pack instead adding properly-camouflaged versions of the Shotgun, M4, MP5M, and M32.
Body Armor as Hit Points: The Medic has this, as he gets 100% protection from damage to his health when he has a kevlar vest, in addition to taking less armor damage overall. Kevlar normally reduces damage to health by about 77%, with a few exceptionsnote Fire damage from Husks (armor protects from 99% of the damage), Bloat vomit and walking into ambient fires (armor stops health damage entirely), and Siren screams (armor is ignored entirely).
Body Horror: The Summer Sideshow Gorefasts. Good Lord, how are they still alive with that many swords in them? And the Sideshow Crawlers, for those of you who like their Body Horror in the realm of medical possibility.
The Halloween Hillbillies also qualify, such as the Crawlers missing their lower bodies, or the Husk and Fleshpound having respectively a fireworks launcher and giant augers grafted to their arm-stubs.
Save for the Scrake and the Stalker, all the standard Specimens are also hideously deformed:
The Clot had its nose and genitals surgically removed, in addition to look emaciated and having several "entry ports" Matrix-style jammed in his body.
The Gorefast is completely skinned, has its left arm amputated at the elbow, and a blade jammed straight into its right forearm, splitting the hand in half. Its lower jaw has been removed, giving the Gorefast its characteristic hissing noise.
The Crawler is a human-arachnid hybrid, and the result is a sickly-grey creature with a man's body, the many eyes of a spider, and spindly spider legs sprouting out of its body.
The Husk is a Specimen with metal protrusions nailed all around its limbs, and what appears to be hooks pulling down the lower eyelids. Also, its skin is badly burned, revealing in some areas the musculature of the creature.
The Siren is an emaciated girl bound by a leather harness with her mouth sagging open, revealing irregular teeth. Her eyes have been ripped out, leaving nothing but dark gaps.
The Bloat is a jaundiced creature whose belly is swollen with vomit, and has a red and bubbly rash down the side of its belly and both of its thighs, most likely due to the Bloat's bile.
The Fleshpound is a seven-foot-tall muscular giant with spiked steel plates ornating his body and replacing his eyes and genitals, with rotating maces for arms and a biological pump strapped to his chest. The pump fills him with sedatives and tranquilizers in normal times, but if he's in danger or is frustrated by seeing a survivor without attacking them long enough, it switches to pure adrenaline and excitants.
The Patriarch is a bit taller than the Fleshpound, with tentacles pouring out of his chest and a severely swollen right eyeball that pops out of his head sometimes. And has a pornstache.
Boom, Headshot: The Sharpshooter perk lives on this trope, but any bullet-shooting weapon can do it. Also of note: decapitations on any specimen (except the Patriarch) will remove its special ability if they don't kill it outright, as well as making them slower and eventually killing them due to bleeding.
Boring, but Practical: The 9mm Tactical you spawn with, while weak, is still useful for beheading low-level specimens, and it's one of the few weapons equipped with a flashlight. At higher Sharpshooter perk levels, it does increasingly respectable damage, nearing the point of becoming a viable primary weapon against all but the toughest enemies or fit for use on all but the hardest difficulties, where a specific damage reduction applies to it.
The Bullpup, the weakest assault rifle in the game, can still clean up a group of enemies and even, in the hands of a Commando or a skilled player, take out tougher enemies such as Sirens or Husks. And you can often find it laying on the ground.
The Lever Action Rifle (commonly abbreviated as the LAR). While slow-firing, it has decent power and it's the cheapest any-perk weapon in the game at £200, making it a good early-game sidearm. Unlike many of the other firearms in the game, it is loaded one round at a time, meaning a player can cancel reloading the full amount if they realize the sudden need to switch to a different weapon or run for their lives. Additionally, its headshot bonus is double the regular damage (moreso if you happen to be a Sharpshooter), compared to most other guns' 10% bonus.
The Knife, which you also spawn with, is nominally a last resort weapon. Equipping it allows you to run faster, however, plus no matter what perk you choose, a hard swing or two to the neck of a Clot or Gorefast is still going to kill them immediately on any difficulty.
The Compound Crossbow seems out of place in a game full of high-end military hardware. But in the hands of a capable Sharpshooter it can tear the heads off of most Zeds with only one shot (the Fleshpound and Patriarch being the exceptions). It comes equipped with a scope (one of few weapons that do), and not only that, bolts can penetrate and kill multiple smaller Zeds with a single shot. Additionally, a maxed-out Sharpshooter will always spawn with this weapon. It has undergone several whacks with the Nerf bat, but since most of those have focused on its cost it still remains a strong weapon for those who can consistently shoot Zeds in the head.
Boss Banter: The Patriarch has a rather large list of lines. "Excellent, another batch of subjects!"
Bottomless Magazines: Not the usual application, but one of the bonuses for a high-leveled Medic player is that guns meant for that perk are given up to double their usual magazine capacity - leading to sights such as loading a 20-round magazine into an MP7 and then spitting out 40note the reasoning for this may cross over with The Artifact - the bonus originally only applied for this one gun, which does have both 20- and 40-round magazines in real life, so when they started adding more Medic weapons it got a little out of hand, or managing to fit 64 bullets into an MP5's 30-round mag. Some other perks get the same bonus, but not to nearly the same extent (Commando weapons only get 5 to 10 extra bullets, for instance).
Breakout Character: For a game with an All There in the Manual plot, and characters that have no actual differences other than appearance and voice (there's a total of two voices for 46 of the 50 playable characters), DLC Mr. Foster seems to be slowly becoming the main character of the game.
British Accents: Taken to hilarious levels. Justified because it takes place in the U.K. and the voice actors (who are obviously both British themselves) are one of the developers and a retired bobby cop.
Bullet Time: Zed time, which occurs randomly when a player does something impressive, e.g. getting several headshots, taking down a tough enemy or scoring a kill at an absurd distance. Time slows for a short time, and multiple slowdowns can be chained by the Berserker and the Commando.
Also done with the Fleshpound, which stops in place and screams angrily before charging at the players.
Not quite attacks, but player characters loudly announce every time they reload or heal another character with the syringe. They also comment on some of the higher tier weapons when they pull them out.
Chainsaw Good: Go ahead and guess what one of the best melee weapons is. The Scrake also has a chainsaw for an arm.
Character Class System: Seven "perks" are available and serve as the game classes. Each has their own requirements for level advancement, but the general benefits are increased damage/reduced costs for that Perk's associated weapons, which acts as a form of training for harder difficulties where money is scarcer and more skill required for survival:
The Berserker: Focuses on melee weapons and combat. Can run quite fast when wielding a melee weapon and is overall more resistant to damage. Properly used, they can act as a meatgrinder when holding a single defensive area, or superb flankers when situations call for running around the map and whittling the Zed count down.
The Commando: Good with all weapons, but shines mostly with assault and battle rifles, for which they get both damage and magazine increases as their perk level progresses. They can also see through the cloaking used by Stalkers and the Patriarch at close range, and can also see Specimen health bars within a given range as well.
The Support Specialist: Shotgun expert; getting more penetration and increased ammunition capacity. They also get increasingly more carrying capacity and un/welds doors faster.
The Firebug: Loves fire. A LOT. Inflicts much more damage with fire weapons and becomes more resistant to it, to the point of eventually being immune to all fire damage and starting a game with a free flamethrower.
The Sharpshooter: Shoots Specimens in the head with pistols or semi-automatic rifles. It hurts them. A lot.
The Demolitions Expert: Blows up Zeds with launched/thrown grenades and planted explosives; becomes increasingly explosion-resistant and eventually starts the game with a free M79.
The Field Medic: The healer of the group; still more than capable to pile up bodies with their frikkin' fast submachine guns. Also tied with the fastest runner on the team so they can catch teammates to heal them. Originally they used only a rechargable syringe to get the job done, but then dart-shooting medic guns were added specifically for them to use to do even better. Oh, and healing others gives a 60% reward in cash.
Charles Atlas Superpower: One of the Support perk bonuses is increased carrying capacity. And even then, other perks can carry their fair share of weapons and ammonote in one particularly ironic example, players with the dosh to afford it can carry both an M79 and an M4 with M203 regardless of perk, even though in the real world the M203 was created specifically because the M79 was too heavy to carry alongside a rifle..
Christmas Elves: The Clots became goblin-like grotesqueries of this trope for the Christmas events.
Clucking Funny: Special Director Edmund Cook, aka the "Commando Chicken", a Cloud Cuckoolander movie cop who wore a giant chicken outfit for his office's party and then began killing Specimens while still wearing it. Then there's the Chickenator, a cyborg version of the same character.
Color-Coded for Your Convenience: The Fleshpound has a bizarre glowing... thing on his chest that Turns Red instead of yellow when he gets mad or takes enough damage in too short a time span. Player characters used to all be green and blue, too.
That 'thing' in his chest is an adrenal pump, and when he gets pissed, it... pumps adrenaline. Which leads to every player in-game yelling 'OH SHIT!' and running, emptying whatever weapon they're currently holding at it, or both.
Even if you go Field Medic, you're going to spend a lot of time shooting at Zeds, unless things start to go horribly wrong. In fact, the Medics are actually good in combat, since the Medic perk gives massive bonuses to your armor and faster ability to heal yourself, not just others.
A higher-level Medic can actually do more of the Combat part of the trope. At level five or above, his weapons (at least the MP 5 and MP 7) have absolutely absurd ammo capacities, he spawns with armor (which for him acts as a second health bar), he gets healing grenades that cause a form of damaging area denial to Specimens, and his normal running speed matches the sprint speed of the Berserker. The weapons still don't put out enough damage to truly qualify him as a Lightning Bruiser, but a higher-level Medic can certainly mop up the lower-level Specimens with ease in between topping off everyone's health bar.
Crazy Survivalist: According to his bio, Sergeant Powers lost his entire family to the specimens. Oh, and he collects freak fingers. Apparently, he disconcerts the rest of the characters, who are plenty crazy themselves.
Creepy Circus Music: The Summer Sideshow maps Abusement Park and Hellride feature variations of well-known melodies.
The medic has upgraded armor and can thus take heavy amounts of damage. Once he loses that armor he's as fragile as the rest of the team.
The actual spirit of this trope is averted by the player characters, who move a bit slower when their health is at about 40, and even slower when that's halved, which is also accompanied by the screen becoming near-totally blood-red.
The Specimens all play this straight if you don't take off their head.
For the Christmas event, anyone who owns both Killing Floor and Team Fortress 2 received a pair of Pyro player models for KF, and Mr. Foster's gas mask and tie for the Pyro in TF2.
Those who preordered The Ball received a player model of that game's protagonist Harchier Spebbington.
Killing Floor's involvement in the Alternate Reality Game surrounding the release of Portal 2 climaxed with the addition of KF-Aperture, a Portal-based map with things such as pressure buttons to open certain doors, Zeds using the apparatus delivery systems to get around, and messages to the player scrawled on the walls. When the ARG was still running, the Trader was temporarily replaced with what appears to be GLaDOS' Anger Sphere.
"Well, it's been fun. Enjoy that thing you do. You know, dying."
Fleshpounds do not play well with others, and don't appreciate other specimens being in the way of them and their target. Scrakes, meanwhile, don't enjoy being pushed out of the way by a raging Fleshpound. One plus one equals an enjoyable diversion. Other specimens are much more forgiving of inadvertent friendly fire, but do occasionally turn on their fellows.
The Bile Thrower was made to instigate this amongst the Zeds, since it uses drums of Bloat bile as an acid-thrower. If a Zed is doused in it while near a Bloat, it will hold the Bloat responsible and begin attacking it instead of you.
Dangerously Genre Savvy: The Patriarch, after a patch, now reacts to multiple players trying to melee him to death to keep him from escaping. He will now flail about in a 360 attack that kills anyone caught in it in about two hits.
Deadly Lunge: The Scrake, the Gorefast and the Fleshpound all start rushing at you once they take enough damage or get close enough. The Crawler does a more literal lunge, attacking by leaping at your face.
Dead Weight: The Bloat is grotesquely fat, but he's not really a zombie.
Deadpan Snarker: The player characters are quick to call out specimens on how outrageous some of them look or act.
"A machine gun for an arm? No effin' way!" "He goes bloody invisible too?" "Rockets, too? Now he's really taking the piss." "Bloody hell, what's he got on his arms?" are just a few gems.
Some of the other responses qualify as well, be it berating another character for not holding still while trying to heal them or one of the voiceclips for asking for money: "Where's my bloody benefits check?".
And then there are the taunts, two separate commands for Zeds and teammates.: "You're pathetic! Like a bunch of bloody Millwall fans! "Who do you think you are, bleedin' Action Man?"
Some characters from the character packs are apparently former Horzine employees - Dr. Gary Glover, a scientist in a hazmat suit, is one of the last survivors of the team directly involved in the creation of the Specimens.
Rachel Clamely, the Mad Scientists daughter was added with the Summer Event Update in 2014. Apparently the only surviving member of her family, she tries very hard to stop what her father begun.
Can also be done unintentionally; as grenades, pipebombs and other explosives can easily kill the user (and in the case of the pipebombs, those can go off if the user shoots them).
Played with in the case of the Pipebomb Hat, where someone deploys one or more of the things in such a way that they are stuck to their own head. Since they are proximity-triggered, it works along the same line of thinking as throwing a pile of grenades at one's own feet. This is typically done against the Patriarch, who had to receive a cumulative resistance to pipebombs in an update.
Subverted with the Combat Medic, throwing your grenades at your feet when being swarmed will actually save you since it heals you and damages the Zeds over a short period of time. Firebugs can do much the same, as incendiary grenades + immunity to fire = easy escape.
Development Gag: Scattered around some of the maps are newspaper clippings that allow you to read the headlines. One such newspaper features the headline "SUSPECTED CULT" with an image of the Clot as it appeared in the original Unreal Tournament 2004 mod.
There's a poster on a lightpost in the Departed map with a picture of a cat saying: "Have you seen this cat? Because it's awesome."
Difficulty Spike: Likely to compensate for fewer achievements than other holiday-themed events, most of the ones for the 2011 Halloween update specifically required players to play Bedlam (an extremely dark and cramped map) on Hard mode or above to unlock them.
Anti-Frustration Features: In contrast, weapon-specific achievements for paid-for DLC weapons can be unlocked with either them or a non-paid-for counterpart.
The Objective mode added with the 2013 Summer event expects you to fight off Fleshpounds starting from the second or third wave - which would be bad enough if you could handle them the normal way, but now you have to stand in place while fighting them or ignore them while moving at a snail's pace. It's far from a majority by any metric, but there have been people asking Trip Wire to remove level-completion achievements for Objective maps, simply because it's so much more difficult in a way people are having trouble adapting to.
Ding Dong The Witch Is Dead: It is possible to kill the Patriarch while there are other specimens alive, in which case they just stop moving while the YOUR SQUAD SURVIVED text is displayed.
What's more, any dead player respawns at this point as usual after a round ended, unlocking the associated achievement for surviving the map in question, even though they technically didn't, if they don't already have it.
Disaster Dominoes: DLC character Lance-Corporal Lee Baron was already in full EOD gear dealing with a bomb threat in downtown London when the Specimen attacks began. He learned that the best way to keep them at a distance was to blow them up.
Disc One Nuke: Once you reach level 5 of any perk, you start to spawn with one of their weapons (or for Medic, his extremely tough body armor). Most of them can make the first wave extremely easy due to you normally being expected to take out the first wave with your 9mm and Knife. If you find some more weapons on the ground, selling them and your starting weapon can often let you get any weapon for your perk that you want by wave 2.
Said weapons lying on the ground can also last you for a few waves if you get some ammo from the trader.
Or can save the entire game if a wave goes really bad. If you find yourself with almost no ammo and in an Everybody's Dead, Dave situation, finding a bullpup or a shotgun with a couple magazines worth of ammo can be all you need to turn things around and pull off a One-Man Army moment.
Double Entendre: Anything said by the Trader could - and is intended to be - taken as one.
In the Abusement Park, there's machines hawking "Rainblow" condoms.
Hook-handed Circus Clots will occasionally say "Just let me stick the tip in".
Double Unlock: An example by default, as paid-for DLC weapons require that one-time payment of real money before you can buy them in-game with virtual dosh. You can use the weapons without buying the DLC, but that requires someone else who did buy the DLC to drop them for whatever reason.
Dummied Out: The game has an incomplete-but-mostly-functional music player feature (likely left over from Unreal Tournament 2004). Giving it a hotkey (such as by editing the user.ini in Killing Floor's System folder, finding the line F11= and changing it to F11=MusicMenu) can allow you to use it anywhere in the game by pressing the hotkey.
Dynamic Difficulty: Specimens grow in numbers as more players join. Most specimens also gain more health depending on the number of living players (particularly the Fleshpound and the Patriarch, instead of spawning more often).
Eagleland Osmosis: Inverted. Suburbia, the first official map confirmed to be outside of the UK (It's in an American neighborhood), has British license plates on some cars and some other out-of-place stuff. This is due to reusing assets from other maps which, as mentioned, take place within the UK.
Emergency Weapon: Besides your starting nine-millimeter, you always have your knife. Its effectiveness is limited, but the "alt-fire" heavy blow can behead weaker enemies in a single stroke on most difficulties, and in the hands of a Berserker, it can be dangerous.
Excuse Plot: So there's a scientist who's mad with grief over the death of his son, and he's been hired to create an army of supersoldiers, but his project gets shut down, so he experiments on himself, and... ah, the hell with it. Guns good. Monsters bad. Apply the one to the other. Get money. Buy better guns. Kill the boss. Repeat from step one.
Expendable Clone: The original purpose of the experiments was to create an army of disposable clone soldiers.
It only gets freakier when you realize that some of them weren't actually made to be soldiers, such as the Scrake, the third strongest enemy, which was designed to be a medic.
Expy: The Bloat is pretty much the Bloated Butcher from Blood, with a dash of exploding on death a la Left 4 Dead's Boomer.
Harold Lott is one to Harry Enfield's "Loadsamoney" sketch character.
Football Hooligans: Chopper Harris, a soccer enthusiast with a long police record of beatdowns taken and given. As far as he's concerned, the mutant apocalypse is just business as usual - only now he gets to use guns.
Four Eyes, Zero Soul: Dr. Kevin "The Patriarch" Clamely. It's more obvious on his loading screen artwork.
Fragile Speedster: The Crawler and Stalker are both fairly fast, but both have almost no health.
The Berserker perk has shades of this. Though he actually takes less damage than others, he also needs that to survive in melee combat. And he's faster than other perks.
Friendly fire is off by default. It can be turned on, however, and your weapons are just as dangerous to teammates as to specimens.
Specimens can kill each other. There is an achievement to get the Bloat to do this. The Fleshpound can too, as it charges through its own in an attempt to kill its target.
Like Team Fortress 2, even without friendly fire players can easily kill themselves with explosives. To a lesser degree, fire-based weapons also hurt the user if used carelessly. Naturally, perks based around these weapon types take less damage from them, but a demolitions expert can still easily blow himself up by accident.
The Clot, Crawler, Gorefast and Bloat are all bare-ass naked, though with no visible genitalia. A close look at the models shows that the dangly bits were surgically removed.
The Siren and Fleshpound are wearing nothing but a few restraints.
The Stalker, Husk and Patriarch are in their underwear.
When going through the game files and code, it comes to light that the Stalker was supposed to be naked. Something involving Executive Meddling forced them to wear black lingerie (indeed, one look at their in-game models makes it clear that their underwear texture was pasted on about 60 seconds before launch).
Within the game itself, there are two levels for recognized mods - the first is stuff that is actually added to the game itself through patches, such as well-made maps. The second is the "whitelist", custom maps and mods that can be used without disabling Perk progression.
Upon Crawlers appearing, characters will sometimes say "Oh great, creepy crawlies. I guess they hop, too."
When the Sirens begin to appear, characters may say something to the effect of "Crap she's ugly. For god sakes, don't let her scream."
The trader frequently advises players to get close to her next location near the end of the wave, which is a smart thing to do if you want enough time to consider what to buy. Or, in some cases, get any time to shop at all.
Give Me a Sword: Don't have the dosh for a bigger gun? Ask your friend for the cash - or just ask them for the gun! Can be done literally by dropping a katana or claymore and letting another player pick it up.
This can be extremely helpful for certain perks like the Sharpshooter, who don't really get access to a weapon that fires on full-auto (and can't just buy an assault rifle because most of the Commando's higher-level weaponry is prohibitively heavy). A higher-level Medic can pass off an MP7, an MP5M, or a Schniedzekk, all of which only weigh three blocks, to a Sharpshooter.
Gravity Screw: The Moonbase map, as would be expected. Sadly, third-party maps making use of similar low-gravity situations have yet to appear.
Guide Dang It: Some weapons affiliated for a particuliar class can also be used by others and benefit from their perks: commandos can use the M4-M203 and keep the lower recoil, extended mags and better firepower, for example. Nothing ever tells you about it, except inspiration. And, if you don't think you can survive a wave as the weapons' intended perk, you'll have to buy them full-price.
Guns Akimbo: You can buy two of any of the pistols, but it makes it harder to aim since when trying to look down your iron sights, you have to eyeball where the center of the screen is instead of just lining up the sights, and shots will deviate from that point when fired in this manner.
Hair-Trigger Temper: Unlike Scrakes, who may go berserk and quickly charge you when their health is damaged enough, Fleshpounds can do this from seeing you and your team long enough (though shooting them enough at once will piss em' off even faster unsurprisingly).
Hoist by His Own Petard: The Demolitions perk grants resistance to explosives in general, meaning that a high-level, armored Demolitions expert can survive a near-miss from a Patriarch rocket. However, when that same rocket sympathetically detonates all the pipebombs the Demolitions expert has carefully laid out to kill the Patriarch... not so much.
Same thing may happen when the Patriarch rushes into the minefield and the Demolition expert is standing too close.
Similarly, the Patriarch can hurt himself when trying to blow open a welded door with his rockets.
Until a patch removed the ability, it was possible to become sealed inside the Aperture vault with the door's welding percentage at 100% for the Patriarch wave. This led to the Patriarch repeatedly shooting rockets into the ultra-durable door, and eventually killing himself in the process. After the patch, he simply no longer attacks the door, and will instead walk around outside taunting you until you unweld the door yourself (the door also no longer respawns at 100% if destroyed).
This can happen to the entire team due to the Patriarch's randomized spawning locations. Dropping a bunch of pipe bombs to set a trap as he rounds the corner? Just make sure you're not near your own pipe bombs when he spawns in.
The Pipe Bomb Nerf made it so that they do not stack damage beyond a certain amount when placed atop/near each other anymore. This doesn't stop them from being awesome against the Patriarch, they must simply be spread out now. Someone did the math and figured out that 14 is the maximum before the decreasing return has each additional pipebomb contributing zero damage to his health. Unfortunately for the Patriarch, 14 pipebombs of explosives going off at once will deplete 51% of his health on even a full server on the hardest difficulty.
Low rank Firebugs often suffer from this as they ignite themselves with the blowback from using the flamethrower in close quarters. Averted once they level up enough to make themselves immune to fire.
Hold the Line: A common plan in most levels since the Welder allows you to funnel Zeds or hold them up by making doors impassable barricades that must be smashed down.
Holiday Mode: The Christmas event made all specimens Christmas-themed, such as Clots disguised as Santa Elves and Gorefasts made of gingerbread and exclaiming "Cholesterol doesn't kill people, I do!" There's also the appearance of three Santas - one playable, one replacing the Bloat, and the other replacing the Patriarch. However, the former appears to be a rather shoddy Mall Santa, the second seem to be clones of the real deal, and the later is a Killer Robot. All the above return for Twisted Christmas 2, which also features a new map, Ice Cave. And since Third time's a charm, the whole crew comes back for 2012... IN SPAAAAAAAAAAAAAAAAACE!!!
For Christmas 2013, no new christmas maps were added (we got Hell and Forgotten instead), but the themed specimens returned, allowing for a Christmas Husk (an animated snowman) to be walking around Hell...
Hollywood Silencer: Averted. The Firebug's MAC-10 has an attached suppressor, but its actual firing sound is rather distinct. When it was first added, it sounded like the AK47.
Hyperspace Arsenal: Excluding what you're currently using, none of your equipment - which in extreme cases can include three full-size shotguns or seven separate pistols, along with separate ammo caches for each - is ever visible on your character model. Anything that is can't be used.
I Know Mortal Kombat: Phil from the "Steampunk 2" character pack. From his bio: "...his so-called elite military training's come from endless hours playing every FPS spat out by the games industry and reading every gun nut magazine he could get his hands on."
The Fleshpound will not change targets unless it loses sight of whoever it was focused on. It will continue to chase and/or horribly mutilate its target through bullets, fire, chainsaws, rockets... and anyone unfortunate enough to be in its way, including other specimens.
Note that none of the specimens will actually run away, but most will actively change target or respond to damage.
On lower difficulties, a fully-leveled Medic or Berserker player counts as well.
Random AXE of Kindness. Kill 15 enemies with the Fire Axe in a single wave.
The L.A.W. That Broke The Camel's Back. Deliver the Killing Blow to the Patriarch with a L.A.W. Rocket.
Quite a few of the Circus Patriarch's lines, too. "Ladies and gentlemen, we hope you enjoyed the show as much as we did! You might say... it was to die for." "It's time to knock 'em dead!" "Enough clowning around!"
The Circus Husk's lines are full of bad puns. "Fire is the hottest new item of the season." "Please remember that there is to be no smoking while the show is in progress."
Some of the Circus Scrake's lines, too. "What manner of monkey business is this?" "This shit is bananas!"
Infernal Retaliation: Most of the stronger specimens have a lot more health than the Firebug's weapons of choice can chew through, requiring considerable time and ammo to put even one Scrake or Fleshpound down. And in the Scrake's case it'll be more likely to trip his charge threshold long before he burns to death. Some weapons have an easier time of it, though, such as the Trench Gun, which behaves like a flame shotgun and causes targets to burn to death even faster with repeated shots.
The player-usable version of the Husk fireball weapon can charge up a more potent blast, but without a low difficulty and a high perk level, a single fully-changed shot still won't be enough to put down Scrakes or Fleshpounds. A high-level Firebug, though, can stunlock Scrakes to death with repeated charged shots, and the repeated shots tend to make the Fleshpound rage in place or flail its arms around while on fire, giving time for even more shots.
Informed Ability: According to story, the Patriarch was nigh-unstoppable ("Armies fell before him, none seemed to be able to kill him, or even harm him"). In-game, a ragtag group of 6 armed only with various different small arms and maybe a rocket laucher and no armor support to speak of is able to take him down on their own.
Instant-Win Condition: When the Patriarch dies, all other Zeds immediately stop moving and attacking as the victory screen and score tally come up.
Averted in Objective mode. Once an objective is completed, all that changes is that enemies stop infinitely spawning - you still have to clear out any of them that are already there.
Interface Screw: Crawlers will blur and darken your vision if they hit you, Stalkers will paint your display blood red, Bloats will stick a gooey substance all over your screen, and Siren screams essentially give you heavy myopia while they last. Even getting bitten by a Clot disturbs your sight more than you might expect.
Intrepid Merchant: DLC character and Action Survivor Mr. Foster is apparently this, in a similar vein to the Trader herself. He also sung at "London's premiere karaoke bar" on the side. He was writing an autobiography and laments the deaths of England's publishers, as doubtless the chapter he is writing about his fight against the Specimens would probably have been a good read.
Invisible Wall: Often to keep you out of Specimen spawn points, but most of the official maps don't have too many. They instead tend to feature gravity barriers, in the form of ramps that the Specimens use to enter the area, but which the players are incapable of climbing over.
The Support Specialist also counts in a sense, as he can carry more equipment than most, including extra grenades. However, his versatility depends on his gear, whereas the Commando has all his perks already available with the default pistol.
With the addition of the Flare Revolvers and the Trench Gun, everyone can get in on this now, with the benefit of not setting themselves on fire as is wont to happen when using the flamethrower at close range. These other guns are also much lighter, and the Support Specialist's bonuses also apply to the Trench Gun, allowing him to either devastate up close or ignite at a distance in a wide arc.
Knife Nut: The Berserker can chew apart early wave enemies with nothing but the weapon he spawned with, and get away with it.
As mentioned elsewhere, it is possible to attach proximity-triggered pipe bombs to your own head, especially useful for the Patriarch wave. Players using this tactic may typically shout the trope name or something similar as they charge toward their target.
There's the enraged Fleshpounds of course, and Scrakes with low health tend to charge the player at high speed and chainsaw them to bits.
Then there's the Patriarch, who gains an enormous boost in movement speed upon turning invisible and frequently uses this to charge towards players who can't see him and strike them with an outrageously powerful melee attack that kills unarmored players instantly on higher difficulties. The Patriarch actually teleports when invisible, proven by him bypassing welded doors entirely.
Patches turned every single Gorefast into one of these - despite their low health (relative to that of the others listed here), they can easily outrun the player and no longer have to stop moving to swing their arm blade. Multiple times.
To a lesser extent, the Berserker is second-fastest class in the game, enjoys a nice damage resistance, and deals out heavy damage with melee weapons. Also, an adventurous high-level medic is even faster, and with armor and the right hardware can dish out heavy damage.
Lost Forever: The Potato achievements, and by extension its unlockable skin, although for the 2013 Halloween event they were brought back. Not strictly for the others, but to achieve them one must wait for the matching holiday to come around, which can feel like forever (doubly so for Halloween, since any given year has one of two mutually exclusive variations).
Love Makes You Evil: The Patriarch views the specimens as his "children", and he gets pissed when you kill them, but the Sirens really take the cake; they're clones of his wife. Which he used to murder his real wife.
It goes deeper than that. The whole backstory kicks off when the soon-to-be-Big Bad misappropriates military funding to clone his dead son.
Luck-Based Mission: A few of the original Twisted Christmas achievements rely entirely on how generous the AI feels rather than any skill on the player's side. For example, one requires the player to kill three Bloats with a bullpup in one wave. With anything less than a full server, the game will barely spawn three Bloats per match if anyone tries to go for it.
A few Berserker-oriented achievements also rely more on luck than on skill, such as the one for chaining four Zed-time bonuses in a row (the game will wait until the last of a group to give you Zed-time for a kill) or the one for killing two Scrakes in one wave with the chainsaw (same issue as the Christmas Bloat achievement above).
Many, if not all, of the "Kill X number of Y Specimens with Z weapon" can be unlocked by using the Faked Players mutator, which is used in Solo play to simulate as many players' worth of Specimens as desired. Of course, you then must survive that many all by yourself instead of learning teamwork taking them all down. Since the mutator makes the game more difficult, it was eventually accepted and now Perk leveling can be done when using it.
The "Dignity for the Dead" achievement, for killing 10 Zeds who are feeding on dead teammates' corpses, depends on A) anybody on your team actually dying, B) the enemies who do him in actually bothering to chomp on his corpse instead of just immediately going for you next, and C) the game actually deciding to credit you with killing the Specimens mid-feed (the game has/had a notorious record for not tracking certain achievements' progress 100% of the time).
The Summer Sideshow event mentions that Kevin Clamely had an equally-insane great grandpa named Errol Clamely, and that either him or young Kevin were responsible for the Zed freakshow.
Made of Iron: Most of the bigger, badder specimens can take stupidly large amounts of punishment, but the Siren in particular is odd - while she can't take as much as Scrakes or Fleshpounds, one would think an anorexic-looking crazed girl in a straitjacket would have less health.
Even odder, she's got a Hard Head! Most specimens' heads will alwaysexplode if half their total health bar is dealt to their head - the exceptions are the Scrake and the Siren, whose heads only explode if 65% to 66% of their total health is dealt to their head (not including the Patriarch, whose head simply doesn't explode).
Scrakes are a weaker version of the Fleshpound, but are far faster and still soak up rifle fire like no tomorrow.
Both of these specimens can tank large amounts of explosives as well. Empty that six-shot revolver grenade launcher at a Fleshpound? If you're off-perk, you most likely just pissed him off.
Monster Clown: What the Bloat and Fleshpound were reskinned as for the Summer Sideshow event.
More Dakka: The Medic's SMGs boast the highest fire rate out of all weapons in the game (but mediocre overall DPS). Bonus points go to the Schneidzekk, which will empty a full magazine in 3 seconds, stat. On the plus side, if you aim for the head, only a Scrake, Fleshpound or the Patriarch will survive the bullet rain, but will be seriously hurting, in the case of the first two.
Nail 'Em: The Hillbilly Horror Event added Vlad the Impaler (also known as the Vlad 9000), a magazine-fed nail shotgun for the support specialist. The nails can ricochet and hit other specimens, which makes up for the terrible range. Halloween 2013 also added the Seal Squeal Harpoon Gun, which appears to be a large industrial rivet gun modified to fire explosive-rigged harpoons.
Never Split the Party: While not as bad as some other games, going off by yourself is a good way to get mobbed and therefore killed. In addition, it's extremely difficult to kill even a single Fleshpound or (after patches) Scrake without serious injury or deathnote Unless you're a high level Berserker or Sharpshooter- the former can fool the Fleshpound into following them around the map, gradually taking off health as they go, and can stun lock Scrakes by beating them over the head with the higher-end melee weapons. In the case of the Sharpshooter, 2-4 crossbow bolts through the head kills everything not a Patriarch, regardless of difficulty. It doesn't help that the toughness of the monsters/their numbers increase at a far faster rate than the raw strength of your party, and using your healing syringe on yourself is only half as effective as healing teammates.
No Fair Cheating: Perks are disabled and unable to be leveled up if a game has any mutator that only spawns low-level mooks or otherwise makes the game easier enabled.
If, however, you decide to add a mutator that makes gameplay more difficult, it will likely still count toward your progress. This was the case with the Faked Players mutator, which allowed for six or more survivors' worth of specimens to spawn in offline single player matches. If you decide to try this, hope you like running around in circles shooting behind you!
No Hero Discount: Logically, the Trader's life should depend on you killing the hordes of bloodthirsty specimens overrunning the area. Apparently that isn't quite enough to warrant a discount. Subverted in that you do get discounts for certain weapons depending on your chosen perk and its level.
Not Using the Z Word: They're "Specimens." Justified in that they're not undead or plague-bearing or even necromancy products, they're military clones turned into brain-dead cannibals. Funny enough, the official nickname for the Specimens is a Zed. Absolutely no one calls them that, in-game or out, but two guns are named for getting rid of them: the Zed Eradication Devices, see Recursive Acronym.
The player characters refer to them as zombies on occasion. Granted, it's always to call them inferior to zombies.
Insult Specimens: "You're too soft to be a zombie!"
Zed (Zee in North America, where "Ƶ" may be taken as Zed) is simply the first letter in the word Zombie, which more an abbreviation than a name. They are officially called specimens. All three terms are correct parlance in the community.
Offscreen Teleportation: The spawn points of Specimens are basically wherever a player isn't looking. Even directly around the corner behind you.
This poor guy had a Fleshpound spawn directly behind him.
Essentially the reaction whenever the Patriarch spawns in the opposite direction from where the players set up their wall of pipe bombs. Doubly so if he spawns in the middle of the group. It does happen sometimes.
There's a voice command specifically aimed at vocalizing this sort of reaction. "We're screwed! Leg it!"
One Bullet Clips: Played straight, though the HUD only shows the number of magazines you could fill with the number of bullets you have. This excludes the pump-action and double-barrel shotguns, the lever-action rifle, and the crossbow, which load one round at a time.
Oddly enough, you can't reload the double-barrel shotgun after firing only one barrel.
Poison Is Corrosive: Bloat acid is marked as poisonous by the game tips. However if you're killed by being puked on, the death message reads: "X was corroded by Bloat acid".
Police Brutality: Constable Briar apparently has a history as a riot cop of "bludgeoning hippies" and "manhandling environmentalists." Such tendencies serve him well against the Specimens.
Powered Armor: Horzine Industries was apparently publicly developing a next-generation suit of combat armor simultaneously to the Specimens. Agent Wilkes, DLC character and British Overt Operative wears it, having secured it from their labs (though it offers no in-game benefit). According to his bio, Horzine "was great at multitasking." Security Officer Thorne also wears what looks to be the same armor minus the helmet and most of the arms.
Power Limiter: That...glowy thing...on the Flesh Pound's chest is constantly pumping it full of depressants, sedatives, tranquilizers and the like. However, if the apparatus senses from its vitals that the specimen is in danger (normally from itself and its own temper), it'll stop with the downers and start pumping it full of adrenaline and stimulants.
Power-Up Letdown: The new Combat Shotgun, which costs 5 times as much as the regular Shotgun, shoots faster and has a pretty reflex sight. The tradeoff? Well... it reloads 35% SLOWER than the regular, holds 2 shells less, does the same damage per shell, has the same maximum amount of shells, and its ammo is also more expensive.
Ragtag Bunch of Misfits: the player characters include, among others, a day trader and his girlfriend, a football hooligan, a raver, a failed mall Santa, and an obnoxious wealthy guy based on Harry Enfield's "Loadsamoney" sketch character.
Rare Guns: One of the assault rifles availables is a German MKb42, the prototype of the StG-44, the first assault rifle ever produced. It's a surprisingly good weapon (more powerful and precise than the AK47 and the M4).
Real Is Brown: There are shades of brown basically everywhere in a map. Some custom maps made official through patches are more colorful, though.
Recoil Boost: The low gravity of the Moonbase map allows for weapons with enough recoil, primarily shotguns, to throw players about if they fire them in the air. Extremely useful for quick escapes, as no Specimens can match the speed you gain in this manner.
Said .44 Magnums are hilariously powerful, making them good sidearms for most players. The Sharpshooter gets a damage boost for them.
Revive Kills Zombie: The Combat Medic's grenades release healing gas that can also harm the specimens.
Reward from Nowhere: You earn dosh by killing Zeds. Where it actually comes from is a secret to everybody.
All things considered, judging from how it jumps up if you survive the wave, it may be a credit the merchant is giving you. The actual thrown money is probably just a graphic representation of donating funds to friends.
Sexy Santa Dress: During the holiday events, the Stalker wears a very skimpy Santa Costume.
Sequel Hook: The Transit - Objection Mode, added with the End Of The Line - Summer Event Update in July 2014, serves as a bridge between the original game and its sequel.
Short Range Shotgun: Mostly averted - the hunting shotgun, in Doom Super Shotgun fashion, is too inaccurate to use past close range, but every other shotgun is still effective up to medium range. Strangely, the AA12 is actually more effective at longer ranges, due to the smaller number of pellets per shell.
The Hillbilly Horror Event for Killing Floor added Vlad the Impaler, a nail shotgun. It has acceptable range and awkward spread, but the nails ricochet quite a bit. And it has a flashlight.
The Trench Gun includes the ability to set Zeds on fire, whether a Firebug pulls the trigger or not. This makes it useful both up close and relatively far away, as up close targets recieve heavy damage from the blast, while further/multiple targets are set on fire and take more damage trying to get closer.
Smurfette Principle: While the Trader does play an important role in Killing Floor, Ash Harding, Mrs Foster, and Steampunk Mrs Foster are the only playable female characters. They snark, swear, and blow stuff up just as much as the male characters do.
The number of total women is increased to five when including the Stalker and Siren Specimens. The Crawler's gender is dubious— it's reskinned as a female Siamese Twin during the Summer Event, but during the Hillbilly Halloween and Twisted Christmas event, it's a male hillbilly with a severed torso and a male reindeer, respectively.
Snake Oil Salesman: The Mechanical Man (Summer Sideshow version of the Husk) is a robotic version of this trope. His product is fire.
Sniper Pistol: The first shot is pinpoint accurate for most weapons, notably with the handguns. Even when dual wielding! That said, you get no crosshair, and bringing up the iron sights with the right mouse button reduces your walking speed.
In the hands of a sharpshooter, it's absolutely lethal. On lower difficulty levels, it's a perfectly usable weapon even late in the game, allowing skilled players to rack up headshot after headshot.
Sociopathic Hero: Several characters seem to be this, according to their bios. Joining their number is Kerry Fitzpatrick, an escaped psych-ward prisoner who put the hurt on the specimens after they put the hurt on his guards. He's probably stretching the "hero" part.
Captain Ash Harding is the only one left from her command and she's pissed that her men died.
So Long, and Thanks for All the Gear: If a player leaves mid-game, all the money they had, along with all their weapons other than what they had equipped at the time, disappears with them. Nicer players tend to at least donate their best gun to a teammate before they leave, though no such luck if their connection gives out unexpectedly.
Soundtrack Dissonance: The Christmas event map "Santa's Evil Lair" has you killing Zeds while the music from The Nutcracker plays in the background.
Steampunk: The prize for unlocking 10/13 Summer achievements is a steampunk Mr. Foster skin.
One of the prizes from the Steam Summer Sale (which can still be purchased otherwise) was the first Steampunk character pack, and as of Twisted Christmas 2 there is a second pack. Each of these new characters is identified by a particular class and even has the in-game class symbol on one arm.
And special guest, Steam Punk DJ Scully! He's still pissed about the Specimens ruining his first big DJ gig.
Stuff Blowing Up: Leave this to the L.A.W. and the plentiful grenades, or the Demolitions Perk and its two dedicated grenade launchers, plus an underbarrel one on the new M4 Carbine.
And now that Halloween 2013 has rolled around, there's an exploding harpoon gun and a six-barreled rapid-fire lock-on mini-missile launcher to play with.
Suicide Attack: Even with the pipe bombs' nerfing, it is still a viable option to attach several to your head for the Patriarch wave (unless you're playing Solo); pipe hats can still remove over half of the Patriarch's health on the hardest difficulty on a full server (assuming you're wearing 14 or more of them!), but given enough time beforehand, it would be better placing said pipes in strategic places and getting the Patriarch to run over them during the upcoming fight.
Survival Horror: The game bills itself as "co-op survival horror" and the monsters are scary enough, but the plentiful ammo, health, and levity keeps the proceedings from getting too frightening.
Twisted Christmas 2 adds, along with two versions of the American M4A1 carbine, an achievement titled "Bloody Yanks" for expending an entire magazine but only killing a single specimen with it.
One of the insults towards other players is "Wayne Rooney is smarter than you!"note For those who don't, Wayne Rooney is player for Manchester United and has the reputation in the UK of being kind of an idiot.
Tactical Rock-Paper-Scissors: Because of resistances some Zeds have to certain weapons, it becomes really important in higher difficulties. Basically boils down to: explosives beat Fleshpound, melee beats Scrake, assault rifles beat Crawlers and Stalkersnote in the sense that they are most efficient as they have large ammo counts, and those specimens come in large packs but are individually weak, headshots beat Bloats, fire beats Scrakes, Gorefasts and Sirensnote as they lose their special charge/screaming abilities when charred.
Taunt Button: With just a few short keypresses, you can insult your opposition ("You couldn't scare my mum!")... or your allies. ("I've met smarter donkeys than you lot!")
Title Drop: Descriptions for community-made maps tend to shoehorn these in, regardless of whether the resulting phrase makes any sense with contextor not.
Turns Red: The Flesh Pound literally turns red when he enters attack mode, and the Patriarch has a red shimmer when entering his invisible fleeing/attacking mode.
Unstable Equilibrium: The Demolitions class as a whole. Players are usually short on cash, and the Demo's weapons are fairly pricey even at discount. Discounts that are harder to earn than those of other perks because of the price barrier. Choosing when to convert from your current class to a Demolitions - by virtue of selling your weapons - is a tough strategic decision, and that's assuming no one else did already. Each shot should be carefully assesed, as it is very easy to go overboard and waste explosives. With a grenade launcher on your hands, though, you can clear crowds in the blink of an eye AND deal with the dreaded Fleshpound, who is weak to explosives. A Demolitions has only two Achilles Heels: Scrakes, and his own explosives.
Not to mention what happens the first time you fight the Patriarch - up till now, you've only been worried about melee (barring the odd Husk fireball) and can outrun everything. Suddenly you're up against an 8 foot monster with a Minigun-Rocket launchercombi-weaponfor a left arm that can turn invisible, run twice as fast as you, smash you across the room in melee, take multiple anti-armour rockets in the face without dying, summon more specimens and heal himself.