Common Infected

"I'm not gonna let these goddamn vampires beat me."

- Francis "They're zombies, Francis."

- Bill/Louis Common Infected are the most commonly faced members of the Infected, and the easiest to defeat. Their strength lies in the fact that they attack in groups, more commonly referred to as the Horde, sometimes as large as several dozen. While they seem capable of ignoring pain, they are as easy to kill as any normal human is. They are capable of climbing ladders and scaling objects once they find a target, and will not stop until it is dead. The default number of Infected that the Director spawns in a horde is around 30. These Infected are fast, sensitive to loud noises and movement, and able to attack in ravenous waves, as determined by the Director. They might not notice the Survivors right away, but when they do, watch out—they're fast, and it won't take long for them to close the distance.

The Horde
The "Horde" is a term people often use as a reference to a medium or large amount of Common Infected. A Horde of zombies can be powerful but they are not invincible by any means. These Hordes can often be distracted very easily in many ways. For example, the Survivors mainly attract the Common Infected via loud noises and bright lights. There are several times throughout the campaigns where the game forces the Survivors to do a certain action that alerts the Horde in order to proceed to the next segment of that chapter, such as opening an emergency door that will set off an alarm, or turning on a noisy generator. There are also other times where the Survivors may accidentally alert them by setting off a car alarm or metal detector, or if Re: Your Brains starts to play on a jukebox. All of these trigger something called a Panic Event, which causes a large Horde to spawn and attack the Survivors. When a pipe bomb is thrown, all of the Common Infected in the immediate area will come to investigate the loud beeps and flashing lights, chasing the pipe bomb and clustering around it until it explodes, killing them. When the Common Infected attack from the front, they do approximately 1 damage on easy, 2 on normal, 5 on advanced and 20 on expert, and when they hit you in the back, they do 0.5 damage on easy, 1 on normal, 2.5 on advanced, and 10 on expert.

Appearances and Action
Common Infected come in variety of appearances, both male and female. They are the victims of the vicious virus only known as The Infection that is sweeping through the area. The infection is apparently transmitted via bites from other Infected.

Common Infected do not differ in appearance from a healthy human as much as Special Infected do. According to the game commentary, the developers designed multiple types of faces and bodies, and would have the computer pair them when spawning Infected, ensuring a variety of characters. This allows for "something around 1500 possibilities". Some Infected models can be seen in any scenario of the game, while others, such as the Infected patients in Mercy Hospital or airport custom officers in Dead Air, are only encountered at certain areas.

When not attacking, they are very vulnerable, usually sitting down, leaning on walls, or simply standing. Usually, when in this state, a Common Infected can easily be taken down instantly by a shove or melee attack; they must be unaware of your presence. They are easily provoked by light, sound, or touch, but are normally only dangerous in large groups or when completely surrounding a player. The heads, arms and legs can all be shot or cut off, this happening easiest using a powerful gun or a slicing melee weapon. The Infected react naturally to gunfire in their vicinity, turning towards the sound to attack the shooter. Shooting one in the foot will cause a very different reaction than shooting one in the chest with a pump shotgun. Usually, if an idle Common Infected receives a non-fatal gunshot wound from a distance they will writhe in pain and clutch the wound with their hands, but if they are running towards the player and receive a non-fatal gunshot wound they will just continue to pursue the player and ignore the pain. This can be most easily observed by shooting them with a pistol. They are often seen engaging in bizarre activities (e.g. vomiting, attacking inanimate objects, fighting each other) when unaware of the Survivors, but begin to rush at the Survivors the very moment they see them. A Common Infected's attack slows down the target player, making it exceedingly difficult to run away from a mob of them that is close to you. They also seem to be at least smart enough to attempt to trap the player, commonly running ahead of him or her and attacking from in front to prevent movement, assuming there is also a horde behind the player.

The Infected appear to lack a sense of self preservation, as they will actively charge into flames, explosions, off of high buildings, and against superior forces of the Survivors and their weapons, even if they have encountered these things before. A possibility is that the Infection has affected their brains to such a degree that they only think of spreading it, or may simply think of attacking anything that wakes them from their stupor. The Infected also are not known to feed or drink, as in the first level of Dead Air, there is a piece of graffiti that says "They don't eat, they don't sleep, what keeps them going?", and it is possible that the Infection has removed the mental ability to perform these necessary life functions. This may indicate that the Infected may eventually die of starvation or dehydration, and possibly even exposure to the elements as the Infected do not seem to seek shelter in conditions that non-Infected would (the theme of the Infected dying out and repopulation commencing is similar to what happened following the events of the film 28 Days Later). However, it's possible that the Infected resort to cannibalism, as evident from the blood on their mouths. It is also possible that the Infected just bleed from their mouths. Common Infected's hair and skin pigmentation is usually very low, resulting in pale skin, and sometimes pale hair. Some Infected, such as Boomers, Smokers, and other Commons may have black or dark hair. The Infected appear to be capable of many acrobatic actions, such as climbing fences, climbing walls and many other actions to get at Survivors.

Extent of Mutations
Though the Common Infected have evidently been mutated the least physically by this strain of the infection, the strain appears to have had a bigger effect on their minds. It seems that they have lost many of their higher brain functions, as they seem to be distracted easily by loud noises and flashing lights, and lack a sense of self-preservation, essentially making them mindless cannon fodder to a certain degree. However, their sense of smell and hearing have been greatly enhanced, possibly explaining things such as Crescendo Events and how the Infected are able to notice the Survivors from the littlest things such as the Boomer bile. It's possible they've had very slight boosts in strength, speed, and endurance—though, again, it appears to be slight, as they don't withstand many bullets or hits in general, or due to loss of higher brain functions, they seem to ignore pain and damage even when there limbs are blown off. They also tend to be incredibly hostile to anything not perceived as being Infected, though there are occasions when two Infected are seen fighting one another, maybe because the infection causes both aggressive and passive behavior. Overall, they seem quite animalistic in nature.



If nothing else, they seem to have some grasp of their current situation, or at least how they feel; generally, idle Infected act physically ill, holding their heads and vomiting as they shuffle around slowly. Occasionally, if you watch one long enough, one of the Infected who is holding their head may begin to writhe in pain, or they may simply lie down and sometimes die without being shot or punched, suggesting that the virus is deadlier than it seems. It is also possible that after Infection, they have a limited life span, just like how people Infected with rabies (The virus the game's virus was based on) have a limited lifespan if left untreated. It could also be through brain hemorrhaging, as Infected appear to bleed out the ears. This also explains why they hold their heads in pain. Another possibility is that these deaths may be the result of an injury that the Infected person received earlier, such as from a gunshot from other Survivors or from a fall that they endured.

Tactics and Tips
Common Infected are only strong in numbers. Sticking together is key to keeping them off you and your teammates' backs. If you are concerned about conserving ammunition, consider using the pistol, which kills them in just a few shots or in one head shot on any difficulty, not to mention it has infinite ammo. It is possible to kill a Common Infected simply by jumping on their heads. To do so, simply walk off an edge which is at least a little taller than the Common Infected, and onto their head. Hitting a Common Infected from behind can instantly kill them, and earn the player the "Spinal Tap" achievement.

Closet mode
When a horde is about to attack, the best tactic is to back into a corner (preferably) or a wall. Assign the front two Survivors to crouch and melee continuously while the two Survivors behind them stand and fire their weapons at them. This works equally well when Survivors have been covered in Boomer bile. Finding the nearest door, closing it, and using a shotgun to blow out a significant chunk of it provides you with a shield that you can see through, as well as keeping the Infected from touching you—very useful for higher difficulties. The most important thing is limiting the area the Common Infected have to attack from. You may also throw a pipe bomb to divert the infected once you have been covered in Boomer bile

Note: This is not recommended for Left 4 Dead 2. This is because the A.I. director will eventually spawn a Spitter that will force you away from your position. Ultimately, this will bring you out into the open, possibly surrounding the player with even more zombies. Also, L4D2 has implemented a fatigue timer which will force a three-second pause after 5 rapidly consecutive melee hits, and then after every hit until a 'cooldown' has been taken. The cooldown usually lasts anywhere from one to three seconds.

Remove Loners
Pick off lone Infected that have strayed away from fellow Infected whenever you can. When entering a new area, swap to pistols or snipe via a hunting rifle and take out as many lone Infected as you can from the entryway as long as it stays quiet. The Director has a tendency to spawn hordes once you reach the mid-point of areas, and this "event" will cause any idle Infected in the area to attack as well. In Versus, however, it is unlikely the Special Infected will allow you to sit in one place long enough to clear a room in this manner, so keep moving.

Weapon of choice
All weapons possess the ability to fire through multiple Infected, therefore positioning yourself so that the Infected are funneled into lines is effective.

Any shotgun can be very useful against the horde, as their shells deal large amounts of damage and can pass through multiple Infected. The auto shotgun/combat shotgun are slightly superior as shotguns go, as they can decimate groups in mere seconds, and there is no pause to pump the gun. A good tactic to use if they are coming through one area, such as a doorway, is to keep your fire pointed at the entry, as the Infected will be clustering together to get through, making them easier to kill. Remember to push the zombies back while reloading simultaneously taking into fact that the shotgun will take much longer to reload than any automatic weapons.

As far as Automatic Weapons go, the assault rifles can do major damage at any range. The Combat Rifle excels mostly at range fighting and ammo conserving, but when a horde is in a player's personal space, it will lack the automatic fire and power to dispatch the infected quickly. The AK-47 is the opposite; while it is poor at best at taking out distant enemies, its high power and low accuracy spread can clear out infected in close range. As for the Assault Rifle, its a medium grade in between both the Combat Rifle and the AK-47, it has a decent power and long range, fully automatic and good accuracy.

Given the Hunting Rifle or the Sniper Rifle, both should only be used to kill distant infected. In a pinch, they can be used to kill attacking infected with their high rate of fire. However, the rifles do excel at one thing: bullet penetration. If multiple infected are being funneled through a tight area or are otherwise "stacked" (like when climbing an obstacle), the rifle family can shoot through multiple infected in a single bullet.

Power of the Horde
The Common Infected are especially dangerous on the expert difficulty. It can only take a couple of hits to down a Survivor, depending on the Survivor's current health. On this mode, the Common Infected also deal much more damage: 20 for each hit on the front, and 10 for each hit on the back. This means a Horde can easily cripple an entire team if they do not pay attention. The Infected often run up behind Survivors and hit them in the back, downing them before they can realize that they are being attacked. To avoid this, constantly watch behind you and look for Infected sneaking up behind your teammates, but do not shoot when they are close to Survivors to avoid friendly-fire. Instead, Melee them off, and then shoot. A good tactic is to always have someone watching behind the group. Communication is also key; always tell other Survivors when they are in danger. Also, it might be a good idea to hop on top of a car or van that has no alarm set because higher ground is usually recommended for fighting large amounts of Infected. Horde attacks also slow down players, if they do not communicate this to other players, they can easily be left behind.

Darkness is your Friend
The Common Infected are obviously known to be attracted by the noise of car alarms and other loud sounds caused by most Crescendo Events, however, most have not realized the flashlight can also enrage Infected. Its effect is similar to that of a pipe bomb, as the bright, flashy lights irritate them, drawing their attention to the player. Using this knowledge may help if two of the Survivors have their flashlights on while the others do not, causing the two "aggro men" to become focused on while their partners are able to break off the rest of the Infected.

Playing smart
Although Common Infected are easily dispatched, it is still very important to eliminate them when possible and still pay attention to one's surroundings. In the event of a horde or Crescendo Event, communication between players is necessary in order to avoid Special Infected ambushes and separation. Having a predetermined path and assigned combat roles can all contribute to a successful campaign or versus match.



Infected tips
When playing as the Infected in versus, you can use the Common Infected to your advantage. While the Survivors are attempting to reach the safe room, there are many ways you can exploit the Horde. Once the Survivors are occupied by the Horde, a competent Tank can defeat even the most organized Survivor team. Boomers can not only summon the Horde but also "extend" it by vomiting on the Survivors after they have dealt with the present Horde. Smokers are also effective during Horde as they can snatch a Survivor and pull them away whilst the others are too busy fighting to help. Smokers can also be protected by the Common Infected. If you have snared a Survivor and you pull him in front of you where you can hit him, the Horde will attack along with you, killing them faster. This circle of Infected makes it harder for the Survivors to kill you. You can even do a substantial amount of damage with a Hunter before the Survivors can deal with the Horde and kill him. Other Infected will also surround the Hunter to claw at the Survivor. There are around 30 Common Infected within a Horde. During a Horde attack is the best time to work together, Special Infected need to cooperate and doing so with the Common Infected can be fatal to the Survivors.

Uncommon Infected
The Uncommon Common, Uncommon Infected, or simply the Uncommon are new forms of the Common Infected introduced in Left 4 Dead 2. They have the same general weaknesses and health as most Common Infected, but there are a few differences that can affect how they're dealt with. Every campaign has its own unique Uncommon Infected, with the exceptions of Dead Center, which has two, and The Parish which doesn't have one at all in the censored Australian version.

Infected CEDA Workers
"Are those guys fireproof?!"

- Nick The CEDA Worker Infected was the first Uncommon Common to be announced and appear in the Left 4 Dead 2 campaign, Dead Center. Players will occasionally come across Common Infected wearing a hazmat suit, which was worn prior to the person being Infected. When killed, there is a chance of them dropping a Bile Bomb (in which case it will be seen strapped to their side). Collecting 10 of these will earn you the achievement "ROBBED ZOMBIE". Upon death, the sound of air hissing out of their now punctured hazmat suit can sometimes be heard. This would mean the hazmat suit was not punctured since the person became Infected, it is thought that the person must have been bitten before they suited up. This may also indicate that the infection is indeed airborne and got inside the suit while the wearer was getting suited up. Through development of Left 4 Dead 2, the campaign the CEDA Worker Infected appeared in changed from The Parish, to extend to Dead Center, to being removed from The Parish completely, having been replaced by the Riot Cop.

Due to their hazmat suits they are resistant to fire, as in they do not burst into flame when in the middle of a molotov and incendiary ammunition just ricochets off them. If idle within fire for extended periods of time, they will die due to the heat. They come in two different varieties: yellow suits and green suits. There were also white suits, but these were only seen in the "Survival" trailer or spotted as ragdolls scattered about certain areas including the Parish, although it was actually possible to fight white suited CEDA Workers in The Hotel, but only before the first update was released.

Clown Infected
"Shoot the clown!"

- Coach

Once a lovable comedian, the Clown Infected is now a victim of the spreading infection. They wander around the Dark Carnival campaign and when they spot Survivors they will charge, calling other Infected in with their noisy, squeaky shoes for an attack. (This does not actually spawn any new Common Infected. It only attracts idle Common Infected nearby.) Any melee attack can honk the clowns nose, if done 10 times the player shall be awarded the "Cl0wnd" achievement, a reference to Left 4 Dead's "Cr0wnd" achievement. Clown pants come in a variety of colors, including red and white, blue and white, and pink and blue as seen in the picture. If killed at a distance, all infected following a Clown will stop, swat at the air around its dead body, then attack the Survivors.

Mud Men
"There really are mudpeople."

- Rochelle The Mud Men appear in the campaign Swamp Fever. They are similar to the Common Infected, except that they are covered in mud and use this as camouflage. Mud men sprint on all fours, although stumble back on two feet when shoved. They also run faster than Common Infected and are not slowed down by water. Killing 10 of them while still in the water, idle or not, will earn you "DEAD IN THE WATER". A hit from a Mud Man obscures the players screen with mud. This increases with successive hits, blurring the screen in a way similar to Boomer Bile. The Mud man's movement can actually be observed in Left 4 Dead. If a player enters an area that requires them to crouch, the Infected will follow them in, but instead of crouching, they will in fact crawl on all fours to get to the Survivor.

Worker Infected
When this unfortunate demolition crew receives orders to tear down an old sugar mill, they instead became Infected. Dubbed Worker Infected, these Infected populate the Hard Rain campaign. Workers are equipped with ear protection, hardhats, and reflective vests making them easier to spot in the downpour. Their earmuffs make them unable to hear pipe bombs, and their blunt melee resistance is greater than usual. (They also seem to be immune to bile bombs when Infected are not covered, since the bile alone on the ground uses the same attention-drawing programming as the pipe bomb, a rather large oversight. They will be drawn to attack bile-coated Infected, still, but will re-target the Survivors once the affected Infected are dead.) They are the only un-cut Uncommon Common to not have specific lines when spotted by a Survivor. They are also the only Uncommon Common to appear on every chapter of its campaign (The other four missing in either the first or last chapter of their respective campaigns.) Though they are reported to be a demolition crew, they are referred to as "Common_male_roadcrew" in the files.

Riot Infected
"Ah hell! Now they're bulletproof?"

- Ellis

The Riot Infected appear in The Parish campaign. While human, they were members of a private security firm hired by CEDA to protect civilians. They became Infected whilst wearing their armor. This gives them immunity to bullets and resistance to melee from the front, but not from behind; they are still harmed by fire. Dead Riot Infected may drop a Nightstick or a pistol. Riot Infected were first featured in the demo and were part of the censorship controversy in Australia and Germany due to rules regarding violence against authority figures though they still appear in the full Australian and German game. They don't have any achievements linked to them, including "CRASS MENAGERIE", as they are unavailable in the Australian version of Left 4 Dead 2. They briefly appear in the zombie survival guide trailer.

Jimmy Gibbs Junior
"If the laws of nature allowed it, I would bear that man's children."

- Ellis

Jimmy Gibbs Junior is a "famous" racecar driver from the South and considered an idol in the eyes of Ellis and Coach. He is dressed in his racing suit and only spawns in the Atrium, with a 5% chance of spawning at all. He is mentioned by the Survivors briefly, saying things such as "If we see him, someone else is going to have to kill him". This may be another play on the remake of the movie Dawn of the Dead, where the Survivors could see Infected versions of famous people that they knew from the mall. He has 1000 HP, no detachable limbs, can blind the player with motor oil (similar to the Mud Men's splatter effect) is not drawn to pipe or bile-bombs and thanks to his racing suit, is nearly fireproof. He, like every other Infected, can be spawned using a console command.

8th Uncommon Infected
This new Uncommon Infected is set to appear in the upcoming downloadable content campaign, "The Passing". It is currently unknown what it may be.

Fallen Survivor (Cut)
The Fallen Survivor was evidently a fairly well-equipped Survivor from the initial outbreak, but unfortunately became Infected later on. He wears militia attire including a boonie cover and three ammo belts with a strap carrying visible molotov, pipe bomb and pills. He also has a first aid kit and a magnum pistol in a holster strapped to his right thigh. His ability was that he would immediately ignite if shot, due to the molotov that he is carrying and deal large amounts of damage to the Survivor. Melee weapons were useless against him because they also would ignite the molotov. Also, he might drop Health Kits that you could actually put into your fourth slot, and you would have had to carry it like a propane tank to heal yourself. Your primary weapon disappears, and the health kit is invisible.

The problem was that the Boomer already held the title of the "explosive" Infected. He was cut from the final game for being too overpowered if killed in a horde. There is a possibility of him being cut due to his ability being extremely dangerous to the Infected as well. He can be seen here, with mods. Interestingly enough, his character model is nearly identical to that of Whitaker. He can also be seen briefly in the "Zombie Survival Guide". He can also be spawned by a console command.