The Boomer

"They've been calling those Boomers. For obvious reasons."

- Rochelle

"Boomer, don't let it puke on you."

- Zoey

The Boomer is an extremely bloated Special Infected. Its mutation has caused it to produce vast quantities of bile, which it uses as a projectile attack by vomiting. If it hits the Survivors, the bile covers them, temporarily blinding them and attracting the Horde. Be warned that Common Infected do 20 damage from the front and 10 damage from the back on Expert so stay extra alert of Boomers. A powerful but fragile Infected, the Boomers role in Left 4 Dead and Left 4 Dead 2 is to slow down and sow confusion amongst the Survivors as a group, giving the rest of the Special Infected an opening to eliminate each individually.

Appearance
The Boomer has short, black hair and appears in sweat pants, with a stain in them for an obvious reason, and navy sweater, stretched to breaking point by its vast gut, which makes it instantly recognizable from a distance. It makes belching, gurgling noises whilst in neutral pose, and groans when it sights a Survivor.

Extent of Mutations
The Boomer has been heavily mutated by its strain of the Infection. It has become extremely bloated to the point that the slightest of ruptures to its flesh will cause it to explode, sending the bile, blood, and other contents of its body everywhere. This is due to the Infection creating large amounts of specialized bile to build up within its body under high pressure. Massive boil-like growths have appeared upon its skin, indicating that it may still be expanding.

Its bile has the unique characteristic of attracting hordes of Infected upon coming into contact with non-Infected human flesh, possibly through the use of pheromones. Similar to the other Special Infected, it is not distracted by such high frequency noises as pipe bombs or car alarms going off.

The Boomer in Left 4 Dead 2 is slightly stronger than the Left 4 Dead Boomer,as seen below.

Left 4 Dead 2
As with all the original Special Infected, the Boomer reappears in Left 4 Dead 2 and has received a slight change of appearance. Its skin tone is more fleshy, it has slightly less hair, and a few more boils. Though when compared to his Left 4 Dead counterpart, he seems more wrinkly and "deflated". The Boomer also has many more details showing the difference in mutation. The greatest change in the Boomers appearance however is the addition of a female counterpart. CEDA has shown some interest in the Boomer. A wall chart detailing its appearance and abilities appears early on in Dead Center, and Infected Hazmat-clad CEDA operatives can be found carrying vials of treated boomer bile.



Female Boomer
The Female Boomer (or "Boomette") is seen wearing a dark blue or black tank top drenched in bile, and shorts. Unlike the male Boomer, she doesn't have boils or growths. Instead, her skin folds forming flaps and perhaps highly Infected forms of tinea on the backs of her legs. The skin on her hands and wrists is black, and looks as if it could be necrosis. Her teeth seem to be horribly malformed either meaning she lacked proper dental hygiene before she became Infected, or that the virus or bile can damage the enamel and form cavities. She makes higher gurgling noises as compared to the male Boomer, and sounds more pig-like. In terms of game play, she functions exactly the same to the male Boomer.The bile appears to be slightly brighter,and it's rare to see a female Boomer.

Abilities
The Boomer may claw the Survivors to do 4 points of damage in Versus. With its primary attack, it can launch a stream of vomit, with which it can hit multiple Survivors who are close to it. If it is killed, it will explode, causing Survivors (and Infected) close to it to stagger, and again covering them with bile. Survivors hit by Boomer bile will be blinded (losing outlines of their team-mates as well) and will instantly attract a horde to attack them, as well as any individual Common Infected who happen to be in the area. They will glow yellow to team-mates, and purple to the Infected. Multiple Survivors hit by Boomer bile will not each attract a horde to them; the one horde will instead attack all of them. This is true also of Survivors who are covered in bile by the Boomers death after the Boomer has used its vomit attack; a second horde will not be attracted until the effect has worn off upon the Survivor first hit, and until the Boomer itself attacks again. The Boomer may vomit on incapacitated Survivors and on those who have been pinned by other Infected. Boomer bile, at least that issuing from the Boomer itself, has no effect upon other Infected.Another ability, explosion, is passive, it is done by Survivors (shooting boomer or meleing/weapon meleing 4 times) or your allies-infected (scratch).If done near ledge, it can knock Survivors off, making them hang on it, or in Scavenge, it can throw gas cans far away.

Attacks
Left 4 Dead 1

Left 4 Dead 2

Note: Information still needed for some areas.

Survivors
General:
 * Listen for the heavy breathing, gagging and burping sounds.
 * Set your subtitles to on. That way you will be able to read the Boomer's noises if it is near. This is extremely useful in noisy situations such as the rainstorms during the latter half of Hard Rain or during finales.
 * Keep an eye out for defensive positions, that way you'll be ready if the Boomer blinds you.
 * Avoid being too bunched up with the other Survivors. There's no sense in all four of you getting puked on at once.
 * On Expert, finding and killing the Boomer before he can vomit or explode is incredibly crucial as the Boomer bile attracts the horde, which on Expert difficulty is much more dangerous than any other difficulty.
 * On Expert, Boomers will often claw Survivors they have vomited on, dealing even more damage.
 * The Boomer is probably one of the most difficult Infected you can deal with. One of the reasons is that it is a very good ambusher, the Boomer will usually hide around corners or it will drop down from a high rooftop to "pop" on the Survivors.
 * take advantage of the fact that Boomers will explode if any part of their body is attacked. Due to their bulk, their arms are often exposed around corners. Just a few rifle blasts could mean the difference between being drenched in puke and escaping unharmed.
 * Only use melee weapons against it if you are shoving it away to shoot it from a farther range.
 * When a Boomer is near, stay away from ledges. The recoil from the explosion WILL push you off.

Before bile vomit or Boomer death explosion: After being vomited on:
 * The Boomer is too close, it's a good idea to hit it with your melee attack (which will push it back to some degree) then back away to a safe distance before shooting or you'll get covered in bile, even though you weren't vomited on.Post-75275-1229068253.jpg
 * Caution: You can only safely push a Boomer back about three to four times (If the Boomer has full health.)
 * Only if the Boomer is sufficiently far away from both yourself AND all other Survivors should you shoot it.
 * Hiding behind something or running away when it's vomiting makes it harmless for some time and may even force it to rush at you clawing.
 * If the Boomer has vomited on someone and is still close to the bile-covered Survivor, shooting the Boomer and (again) covering the Survivor in bile will not attract an additional horde.
 * Know that a massive horde will immediately descend upon you (and any others who have been slimed).
 * Hold your fire! Since you can't see, friendly fire is the most likely result. You need to:
 * Run to a defensive position (corners and doorways are particularly good).
 * Crouch! Other Survivors will be able to shoot over you safely if you do so.
 * Use melee continuously to survive the incoming zombie horde.
 * Once your sight starts to clear, mop up with your weapon.

Helping a slimed Survivor:
 * Stay close to the stricken Survivor.
 * Help melee the horde back or shoot if the blinded Survivor stays safely crouched.
 * Help the stricken player to safely get to a corner or high ground to protect him from the Horde.
 * Throw a pipe bomb to distract the horde, however if you throw a bile bomb it will go to waste, as the Survivors covered in bile are primary targets for the common infected.

Infected
While it may be difficult to be completely stealthy as a Boomer, try to hide in shadows, around corners, or within hordes of Common Infected. But be careful: Survivor Bots can see you! To ensure that you slime the Survivors, vomit on them at close range, then run up to attack them so that they will be more likely to shoot you. You will explode and spread the bile within a certain radius around you. Once you cover a Survivor in slime by either of the two ways, the Survivor(s) will appear with a bright purple outline replacing the original one indicating health status.




 * First and foremost, the Boomer can only spawn one wave of Infected per Survivor at a time. Vomiting on a Survivor and then exploding on the same Survivor will not generate additional Infected despite getting one person "twice". To generate additional Infected, you must either explode on a "non-purple" Survivor, or wait until all Survivors are no longer surrounded by a purple aura with bile and then strike again. Therefore; he who pukes and runs away, lives to puke another day. The best tactic for this is the "ninja-boom". If it is possible for you to run away after you vomit on the players then run to hide. Hide farther down the level and wait for your vomit to recharge. Once it has, initiate the same attack - vomit and run.
 * Boomers are large, making them easy targets. If you manage to slime a group of Survivors in a place where running away is going to be difficult, and finding cover will take some time, don't be afraid of running in and clawing them, as this will deal extra damage. While in the middle of the chaos, it can also confuse the Survivors from which direction the horde are actually attacking them from. Also, if they're not careful, they can shoot you once they're clean, resulting in being covered again.
 * However, often it is more effective to back off and find a place to sit and let your bile recharge, as some horde attacks can take up the full extent of your recharge time. If you're lucky and have good positioning (ideally sitting in a window above the group before they emerge from a doorway below), you can score multiple horde attacks by raining bile down upon them each time they emerge after the horde, causing them to have to huddle back inside, depleting their health, and giving your teammates ample time to respawn and deal damage.
 * Since the Boomer has a very distinctive gurgling noise, choosing a good spawn-time is crucial. Do not spawn when the Survivors are far away and attempt to rush them, especially in the open. Even if you are hiding, the Boomers gurgling will alert the Survivors of your presence. If you spawn inside a room only a second before the Survivors pass the room's door (make sure the door is open/has a hole in it), you can do a spawn-vomit succession without giving them time to react. If you don't manage to cover all of the Survivors, you can either run at them clawing, hoping to explode in their face, or escape and return later.
 * The Hunter can pounce on the Survivor covered in bile to add terrible confusion to the mess; the bile will summon the Infected, who will create a meat shield for the Hunter. By the time the other Survivors are able to get to their pinned friend, it may be too late. However, it would be better to pounce a Survivor not slimed, as the blinded Survivor cannot see their pounced friend.
 * Unfortunately there is a delay between the time where a Bile attack leaves the Boomer's mouth and before it hits a Survivor in which if the Survivor kills the Boomer the Bile will disappear in mid-flight, leaving the Survivor unharmed.
 * If you are playing a Hunter and a Boomer vomits/explodes on the Survivors, they will often huddle up in a corner "spamming melee". However, if you, the Hunter, pounce into the top of that corner instead (pounce over the Survivors heads), you will land on a Survivor and his teammates' melee will not hit you. Since the Survivors are blind,Hunters can perform this plunge into the walls top corner without being afraid of getting shot and hopefully kill a Survivor.
 * During Tank attacks, take the opportunity to vomit on the Survivors. This is a particularly helpful and effective action, as the horde sticks Survivors in place, and forces them to deal not only with a Tank, but dozens of zombies. Often getting a well-placed vomit attack in during a Tank attack spells death for the Survivor team.
 * While a Survivor is covered in bile, they cannot see the outlines of the other Survivors (or that of the Hunter, Charger, or Jockey after being pinned). While another Infected is attacking a straggler, take the opportunity to cover the other Survivors with bile. While this may cause the Horde to spread out, it is important to impair the other Survivors' vision so that it becomes more difficult for them to work together and to aim.
 * Most Survivors tend to target The Boomer the instant one is heard or seen. One can hide next to cars with alarms and Witches to trick Survivors into shooting them, triggering the panic event or the Witch.
 * Waiting behind doorways and in small rooms will guarantee at least one successful slime.
 * If you are stuck outdoors, hide in a place where the Survivors cannot see you and wait for them to be distracted by something else, then run in and vomit.
 * The Boomer is the only Infected class that should almost always attack an incapacitated Survivor. If you can, try to vomit on downed Survivors so that the Horde comes for them. This makes them almost impossible to rescue as every zombie hit interrupts a rescue attempt.
 * You can also stand on rooftops and vomit down on the Survivors or jump down and hope they shoot you. If you explode in mid-air, your innards will rain down on Survivors as well.
 * Don't hide right next to thin walls. Not only can Survivors shoot through most of them, your ample mass may stick through (due to vector errors), giving them a free kill. The slime from the aftermath will, unfortunately, be unable to get through. Try to hide slightly off the wall to minimize cheap kills.
 * When you pop, you knock everyone back. This includes both Survivors and all Special Infected even when they are using their special attacks. The good news is that you can knock Survivors off of high ledges; the bad news is that you can do the same thing to Tanks or other Special Infected. Take care of where and when you explode!
 * If you are a Hunter, Smoker, Charger or a Jockey it is far more useful to attack Survivors that have not been puked on if they are all close. This of course does not apply to a survivor that is straggling behind or too far ahead.
 * If you have used your boomer bile and missed a downed survivor, you can put the Survivors into some extremely sadistic lose-lose situations. If you can, sneak up on a single incapacitated Survivor and simply stand right next to him or start clawing him. The incapacitated Survivor cannot do anything about your presence other than shoot you, which will cause him to be covered in bile, resulting in swift death. You can also so the same to a pinned Survivor, and if any of his friends try to shoot the Hunter or Smoker pinning him, they may hit you, causing a similar result.
 * Remember, that a Boomer has no pinning attacks, meaning that even with a full team of Infected, you can't all pin a full team of Survivors, leading to instant Survivor failure. You must, instead, try to have your horde incapacitate at least one Survivor, allowing your Infected allies to sneak in and get all the other Survivors while the single incapacitated Survivor is helplessly pounded by the horde you summoned.
 * A good tactic when playing as the boomer, especially on the swamp fever campaign, is to try and hide once you have used your primary vomit. This gives the other infected a chance to do extra damage. Rinse and repeat.
 * One of the best ways to do lots of damage is to spawn as close as possible to the survivors as you can. Then jump around a corner once you have a chance to explode on all of them, or vomit and run away.
 * If the 3 survivors are covered, chargers can take the clean one far away from the rest. This shouldn't be that easy to counter for average players.
 * While fires are hazardous to any players, it has a limited amount of usefulness to the Boomer. Depending on the situation, you can intentionally catch yourself on fire, static or not, and run straight for the Survivors. Since the fire chip away your health, you literally turn into a ticking timebomb. Even if they melee you away, you would probably explode before they are able to run a safe distance away. Situations where this tactic can be used is during a horde attack, when your teammates are attacking, when you are close to the Survivors, when you are recharging your vomit with no hope of escaping or if the Survivors decided to use their molotovs. An added bonus was the fact that the Boomer will be wailing softly in pain, which is noticeably more silent than his gurgling noises, hence a Boomer on fire is usually hard to detect via noise and often catch Survivors by surprise.
 * Before the recent patch in the pc version in the beginning of No Mercy while the survivors were moving downstairs to the apartments a boomer in versus can puke upwards the stairs and blind the survivors.

Boomer Tips and Tricks Gameplay
Here is a video with a lot of helpful information and tactics for the Boomer.

http://www.youtube.com/watch?v=rqc6p5KU06E&feature=channel

Behind the Scenes


In the Developer Commentary, it's mentioned that originally the Boomers explosion simply caused damage to nearby players, and that the horde-attracting abilities were assigned to the Screamer, another Special Infected that was cut from the final game. When the Screamer was dropped, the screams that formerly attracted the Horde were changed to the Boomers bile. The Boomer's old explosion behavior can be seen in this video at 1:57: http://www.gametrailers.com/video/quakecon-2007-left-4-dead/23268

When the Boomer's bile was first added to the game, it was red. It was replaced by the green seen in the final version.

In the leaked Half Life 2 Beta files, this can be found "A bloated, disgusting, fluid-spurting zombie created by a poison headcrab." commenting on the poison zombie. This almost perfectly describes the boomer, bar the headcrab.