Tactics Playing As Infected

In a standard 4v4, each team will take turns playing as the boss infected (Boomer, Hunter, Smoker, or Tank) and the survivors (Bill, Zoey, Louis, and Francis).

Boomer
As a Boomer, your job is to slow the survivors down by attracting the Horde. The director will spawn one Horde for each survivor vomited on for a maximum of four (Not counting panic events or random director spawns). As a Boomer, you want to hide and ambush survivors since Boomers have the lowest amount of health, emit a lot of loud burping and gurgling noises, and can be killed by anything as simple as a single ranged Shotgun blast. The Boomer acts more like a support class, as they don't dish out much damage on their own. Because of this restriction, they excel when placed at the start of any coordinated attack. Their main attack attracts the Horde, causing survivor teams to panic, which creates ideal opportunities for the other special infected to move in and deal serious damage. Remember that you have very low health and will explode in only a few shots. If you try to rush at the survivors in the open, they will simply kill you before you get within vomiting range.

Another weapon of the Boomer is that it explodes when it dies and covers any nearby survivors with bile, which has the same effects as vomit and also causing them to reel back. This explosion is a good way to cover any survivors you missed because inexperienced players have a tendency to shoot on sight instead of using a melee attack to knock it back a safe distance. You can vomit on unsuspecting survivors below with impunity if attacking from rooftops. Then jump down to let them shoot you in blind panic! Vomiting on a person who is already covered in bile does not spawn another Horde, so you should either retreat until you're ready to vomit again or to get as close to other survivors in the hope that they'll cause you to explode bile onto other survivors.

Experienced Boomer players can use the knock-back effect of the explosion very effectively by knocking survivors off high ledges normally doing large amounts of fall damage and, if high enough, will cause instant deaths. As a Boomer, don't be afraid to start clawing at survivors if it doesn't look like you can escape.

Hunter
A Hunter's job is similar to that of a wolf. The Hunter excels at picking off any stragglers or lone wolves in any team. A Hunter's pounce pins a survivor, leaving the victim completely helpless, until the other survivors melee the Hunter or effectively kill it.

Because the majority of players travel together, Hunters will not commonly find stragglers. Because of this behavior in the opposition, Hunters generally can not successfully initiate an attack and expect to do serious damage. As a result, Hunters are best sent in during a Panic event, when survivors are blinded by vomit or bile, or any other cases in which the survivors' attention is focused elsewhere. Because of this lack of opportunity, Hunters must stay stealthy and hidden until opportunities present themselves.

In order to pounce, Hunters must remain crouched for a limited time. However, being crouched causes the Hunter to growl loudly, broadcasting his arrival on the scene to any nearby survivors. Also, whenever survivors are in view of any of the Special Infected, the Special Infected will emit auditory sounds, such as aggressive growling in the Hunter's case. Because of this, Hunters should remain standing and out of sight until they are ready to attack.

Another effective tactic is to continuously wall jump. Hunters emit a distinctive scream during flight. An experienced wall-jumper can effectively distract a team, slowing them down, and buying the Infected players additional time, which may cause the Director to spawn a Horde.

For more information on how to wall jump, How To Wall Jump. A rather effective resort for the Hunter is to rely on his melee attack. Hunters can run up to survivors and claw at them without giving off many of the tell-tale signs of the presence of a Hunter.

Smoker
As a smoker your job is to ensnare a survior and pull them away from the group. Your "Tongue" attack leaves survivors helpless after about 2 seconds of being ensnared, A survivor with quick reactions can break himself out of your "Tongue" most of the time. But a well placed smoker in the midst of a horde attack can spell disaster for the Survivors if not dealt with properly. Always look to be either up high or in a dark place the darker/higher the less chance the survivors will be able to shoot at you. A good survivor can recognize the Wheezing and Coughing of a smoker and will be on the alert to his team mates being snared. If you want to be really annoying stand by an "Alarmed Car" Like the one in the No Mercy apartments chapter by the subway Stairs if you stand on/by the car and pull a survivor over to you the other survivors will have no other choice but to try and save the person you pulled so any stray bullets goes stray and sets the alarm off attracting the horde buying your more time to attack while the horde joins in carnage. The witch/smoker tactic is devestaing as the smoker stands in close proximity to a witch and pulls someone in causing the witch to attack. Good smoker players excel at using the enviroment against the survivors this can be by dragging them down from a higher part of a level as the fall will do alot of damage and if the lower area is just where the survivors have had to climb up from this will mean that they will have to reclimb back up to the higher area leaving them away from the group and will slow down the group while they wait for the lone suvivor to catch up.Smokers can also drag survivors through fire that again causes large amounts of damage while either forcing another survivor to run through the fire to release there tied up team mate or wait until the fire dies down while the smoker does damage to the tied up survivor.

Tank
The Tank, The most dangerous Boss Infected by far able to withstand lots of punishment and incap survivors in a few punches, The tank is given out at random but usually goes to the 2 players with the highest score. When you get the tank you will usually spawn a way in front of the survivors, Start running towards them as soon as you spawn for two reasons, A Because the Tank Music will play and survivors will prepare for a tank and B Because of the "Control" Effect, If you cant see the survivors the tank will get angry and the control meter will go down, When the control meter is empty you lose your turn with the tank and control moves to another player so you must always be on the move/attack! As a tank you need to use the enviroment to your advantage! Punch a car at a survivor its an auto incap! On Finale's you will usually get 2-3 tank spawns, On No Mercy try and punch survivors off of the roof for an instant and free kill. Always look for a lone survivor as a tank! If the others run off but one is trying to heal or gets trapped by infected score an easy incap on them! They wont be able to get far but if your running at all the survivors and there all unloading clips into your face your speed will be dramaticly reduced and they will just run and shoot and usually kill you before you do any real damage. Also note if the survivors set you on fire you will eventually die no matter how much they shoot you or how many you kill you will die after being set on fire by a molotov/gas can.So dodge them at all costs. Dont punch any survivors already pinned by a hunter or constricted by a smoker because that kills the hunter and its a waste of there life.Tanks can also punch down Safe room doors but only the ones the survivors start in.

Co-Ordinate Your Attacks!
This is by far the most important factor in a left 4 dead versus match. If a hunter pounces on his own he will just get killed before he can do any real damage. If a smoker tries to constrict a survivor they will just get freed without any real effort giving the survivors about 20 seconds while you respawn and get into position to try again. The best tactic for coordinating your attacks is let the boomer vomit on as many people as he can then the hunters pounce from there hiding spots and the smoker pulls someone away.

If the boomer vomits on 1 Person (Fail) then pounce/constrict the other 3 who haven't got boomer bile on them! The 1 person will be getting attacked by infected and when you have boomer bile on you you can't see that other survivors have a hunter on them or smoker constricting them! Also coordinate your attacks with the tank, wait for the tank to spawn and let him cause havoc then pounce/constrict on any survivors you see lagging behind or running off too fast. If you're a boomer on a tank spawn throw up on some people and its pretty much game over; tanks are hard on there own but with a horde of infected slowing you down you don't have much chance of escaping.

Notes on tank spawn: you don't have control of the tank for a good three or five seconds, and you can expect the computer to run straight into bullets or fire or other nasty things. If you happen to spawn in a poor situation (all survivors green with molotovs and pills and no infected to help you) then turn around and wait for as long as you can. You have about 20 seconds before you lose control and the tank is handed to another player, but it is better to pass it to someone else and win the match then get blown away without touching the survivors.

Spawning
Most of the time during a versus match the infected team will spawn one smoker, one boomer and two hunters but sometimes it will spawn an extra hunter in replacement of a smoker creating a more aggressive group; this seems to happen randomly, but it appears related to which infected die and which live. For example, if two hunters and the smoker live but the boomer is killed, the boomer player is more likely to spawn as a hunter. Also in very rare circumstances there have been spawns of completely hunter infected teams; this group can cause major problems even for the most experienced teams.

Get to know all the maps! The places you can climb to, good ambush spots, etc. Look for climb spots that players can't reach or for strategic walls you can knock down. In general, the boomer should spawn ahead of the survivors so he can properly ambush while the smoker should spawn behind to pull someone back. Hunters should be near the smoker of boomer to take advantage of the chaos they create. Obviously this is all situational as there will be times that you will want to spawn behind as a boomer and run in (if the survivors are being tanked, for example).