The Tank

"Why can't that thing be on our side?"

- Rochelle

"Run or shoot!?"

- Louis

The Tank is a Special Infected of gigantic proportions. The Infection has caused a huge amount of muscle growth, granting it an extreme amount of strength. This monster is capable of punching large items such as cars into the air or throwing blocks of concrete it rips out of the ground at Survivors, and bashing through otherwise impenetrable walls (including the Safe Room). The Tank keeps a high profile, able to be heard by the Survivors from a great distance due to its loud roars, shaking ground when running, and its distinct theme when attacking. The Tank is designed to make the Survivors panic and split up into different directions so that other Special Infected may get to snatch you alone; this happens commonly among new players. It is also designed to absorb lots of damage and still be able to run towards the Survivors. The immense strength and incredible toughness of the Tank make it a terrible foe in combat, especially to inexperienced or uncoordinated Survivors.

Extent of Mutations
The Tank has been heavily mutated by a strain of the infection. It has developed immense, thick muscles that not only indicate its incredible strength and endurance, but make it nearly bulletproof, resulting in extreme fire-power being needed to take one down. However, this increase in muscular tissue makes it a large target and, like other Infected, is highly flammable. Its mind has also been heavily affected, making it extremely bloodthirsty even for an Infected. It could also be said that the Tank is in a constant state of rage, hence its preferred form of attack of charging the Survivors and pummeling them to death and the frustration meter in Versus mode. Because of this rage the Tank will not hesitate to kill or throw objects out of its path, including other Infected, in order to get to the Survivors. It is not affected by minor distractions such as the flashing lights on pipe bombs, and does not appear to be attracted by car alarms going off. During the intro video of Left 4 Dead, however, a car alarm does alert a Tank. It is commonly thought that the Tank's lower jaw is missing, but close inspection reveals that the lower jaw is intact, behind the tongue and almost completely swallowed by the bulging head and his muscle.

Because of its massively increased muscle growth in its upper body, the Tank cannot use its legs for fast movement without the support of its arms for knuckle-walking, similar to a gorilla. The Tank's legs can still briefly support its own weight when landing or when pulling and hurling concrete, showing that the Tank's legs might have been changed, but not much, seeing also that the Tank could still move quickly. It also has a large, noticeable wound on its chest on both Left 4 Dead and Left 4 Dead 2 models.

Left 4 Dead 2
The Tank is now completely bald and his skin has a more rough and dry texture. It should also be noted that while in Left 4 Dead the Tank's lower jaw can be seen, in Left 4 Dead 2 the Tank's lower jaw is now completely absorbed by its muscle and only the tongue flops out. The Tank's fingers are now smaller, and its back is more rounded.

The Tank's behavior has also been modified to devastating effect. Instead of focusing on one Survivor until they are dead, the Tank will attack whoever is closest and not kill an incapacitated Survivor if there are healthy ones nearby, which makes it extremely difficult on Expert, as a Tank can easily wipe out an entire team within seconds. However, if the Tank cannot reach or find any other Survivors, it will pound the one on the ground. The Tank will also start smashing downed Survivors if other survivors crowd around the Tank and the downed Survivors.

Tactics

 * In some levels there will be small passageways such as vents. The Tank may get stuck in these passages, giving you time to kill it without it being able to retaliate. If Survivors are too close, however, it can still use it's punch attack to throw them back or incapacitate/kill them.
 * In Campaign mode on Left 4 Dead, Survivors should consider if it is a good idea to set the Tank on fire, as it will give it a speed increase (unless Survivors are in an environment where the Tank will struggle to navigate). Consider the health of your teammates and yourself, your environment (if it's open and no objects are blocking the Tank's path), and whether you have the correct weapons to deal with the Tank. On a difficulty like Advanced or Expert, it can eliminate you with terrifying speed. However on Versus it is generally an excellent idea to set the Tank on fire, as it will deal damage instead of setting a timer, the constant damage resulting in a speed decrease. In Left 4 Dead 2, a burning Tank in Campaign mode will act like one from Left 4 Dead Versus; it will take damage over time and therefore be slowed down.
 * Listen carefully for the Tank. Make sure you can distinguish it from Hunters (the sound of its growling). You can often hear a Tank breathing and grunting before it attacks. You may want to turn subtitles on, so if there is a Tank on the map, but the music cue hasn't started yet, then the growls and roars will appear on the subtitles and you will have time to prepare for an attack. Sometimes part of the Tank's body is sticking out, like an arm, due to its gargantuan size. If you see it, you can get ready for the unavoidable fight by healing or throwing a Molotov to catch it by surprise. Occasionally the Tank will be in a part of the map that the Survivors don't normally pass by; if you get past him without alerting him, he will respawn in your path somewhere else. By the time the Tank is in your line of sight, it is often too late to plan an effective defense. If there are no obstacles, run backwards so that you can shoot on the run. Otherwise, go ahead and open up on it. Be aware that the nearest Survivor that shoots the Tank is the target. Running ahead of others may end up triggering a Tank that your teammates won't be ready for, and by the time they do reach you, you may be down and stuck behind the advancing Tank or even dead.
 * It is easier than rumoured to dodge the Tank's punches by jumping across the Tank. Time a jump such that you jump across the Tank right after it swings its fist and you would find yourself right behind the Tank, giving you a huge target for rapid shotgun fires.
 * If you happen to run out of ammunition on your primary weapon, but have a melee weapon, don't be afraid to use it. It takes 20 hits to kill a Tank with a melee weapon, but be cautious, since walking up to the Tank and attacking it at a close range is dangerous, especially on higher difficulties. It is best to try this when a Tank is focused on a single Survivor, as the Tank's AI usually causes it to attack one Survivor at a time until they are incapacitated. However, should it come to the point that you are left on your own and stuck with a melee weapon, you may want to consider the tactic of using a melee weapon on the Tank only while it climbs over a platform, or after dodging its attack. Should it come to the point that you are badly being beat up by the Tank in one corner without escape, draw your melee weapon and strike it as it may be the best way to maximize damage to the Tank before being incapacitated or even saving yourself through the massive damage that your melee weapon can inflict.
 * The Tank can find you even in the dark, so hiding with the flashlight off is futile.
 * The Tank can knock down the beginning safe room door. However, if one were to crouch behind the door, it will cause the Tank to clip into the door and become stuck under the window, rendering it immobile. This is exceptionally helpful on harder difficulties.
 * The Tank climbs obstacles much more slowly than it can run; exploiting this fact will provide you with more uninterrupted firing time.
 * When the Tank is forced to move while crouching, it moves extremely slowly. Try to get the Tank to go in through a window, vent or any other small area, it will give you a few more seconds to kill it.
 * If you are incapacitated, do not shy from using pistols on the Tank since every bit counts, on easy and sometimes normal it is actually possible to solo a tank with your pistols while incapacitated.
 * If you're in an area where falling is possible, such as the Rooftop Finale, make absolutely sure that you are between something solid and the Tank, so that its attack won't launch you on an incredible 30 story journey to your death. However, if desperate, and the Tank's current target, run off the edge (don't jump) and it should follow you off the edge (the Tank keeps at its target even if they are incapacitated in Left 4 Dead). Once the Tank falls, have your teammates help you to your feet and keep on going.
 * Sometimes an AI Tank will forget that there's a bottomless pit between you and it, and will run straight into said pit. This is most exploitable in the elevator shaft right before the Rooftop Finale. Standing on the other side when a Tank spawns may cause it to drop down into the hole.
 * There are many places that can slow it down, do damage to it and maybe even kill it bewtween you (such as a propane Tank, the pit of fire in the debris in the finale of Dead Air, or the explodable gas station in No Mercy) are very VERY useful if used right, if you don't want to use a grenade or don't have one.
 * If a melee attack is used, the Tank will chase whoever hit it; this is extremely useful when a Survivor is incapacitated and is being pounded on, enabling a healthy Survivor to lead the Tank in circles while someone else gets the Survivor back up and into the fight. However, the incapacitated Survivor must not shoot the Tank after it has been hit or else it will turn right around and keep on punching them.
 * Avoid bunching up together such as in a closet or corner and trying to unload onto the Tank while it assaults you. Doing so will make you a very easy target for the Tank. If there is a prop around such as a log, car, or forklift, the Tank can send it flying towards your direction to instantly incapacitate everyone. Doing so will also make the Tank's punch hit multiple Survivors at once, and hiding in a closet can entomb you inside of it. The best action may be to stay apart but within range of your teammates if any Special Infected tries to pick them off.
 * If there is a Minigun or Heavy Machine Gun nearby, you can use it to force the AI Tank to switch targets. The AI Tank always goes for the person mounted on the Minigun/HMG.
 * If you and your teammates are equipped with Auto Shotguns, you may be able to kill the Tank before it can inflict damage to anyone. (Auto shotgun damage ~3000 damage per magazine; see Tank health statistics). In addition, a propane tank can deal a fair amount of damage to the Tank and stumble it, allowing you to quickly finish it off with shotguns as it is stumbling.
 * After the crane Crescendo Event in the second stage of Dead Air, try lighting the Tank on fire and making it fall between the buildings. This will cause the Tank to lose a significant amount of time for an attack, and often it will burn out before climbing back up. If no one else damages the Tank, then you would earn an easy "Man vs Tank" achievement.
 * If you are close to the safe room at the end of a level, run into it. The Tank can't get in, and you can shoot at it through the door. Keep your distance from the door, though. It can still punch you if you are too close. Do not try this at the start of a level, as it can easily break the safe room door down, trapping you.
 * In Left 4 Dead 2, it is possible to cover a Tank in bile without alerting it, and so it will not attack the Survivors as the Common Infected attempt to tear it apart. This can be extremely useful on Expert when your team is hurting. Do not depend on the Common Infected completely, though; shoot at the Tank as well, but make sure you don't kill too many Common Infected in the process.
 * Be wary when using Bile biles and Molotovs on the Tank at the same time. Common Infected running through the flames to chase the Tank will light on fire, rendering the Common Infected useless unless there are CEDA Agents present to attack in Dead Center; but even then they aren't very common, meaning the summoned Horde is destroyed and you are a Bile bomb short.
 * In Left 4 Dead 2, you may also want to consider whether or not you want to throw just a Bile bomb at a tank. This depends in part on the play mode.  In Campaign mode, the bile will not have the blinding effect on the AI that it would have on a human player in Versus.  In any mode, throwing a bile also introduces a horde, and if you do not deal with that horde before the bile wears off, you will have to deal with them as well. On the other hand, it will highlight the Tank, allowing all players (providing you are not playing in Realism mode) to see where the Tank is through walls.
 * If you hear a Tank nearby, kill all idle Common Infected you can see to prevent the risk of being hit or blocked by Common Infected when dealing with the Tank.
 * Regardless of difficulty, AI Tanks will generally do a victory taunt (roaring, punching the air, beating its chest or slamming its fists on the ground when on fire) when it successfully incapacitate or kills a Survivor. Use the opportunity to unload your ammo on it while it is stationary, or if you are close to it and willing to deal massive damage, hit it with a melee attack and then run.
 * In Left 4 Dead, Tanks will usually pound on an incapacitated Survivor, making him/her a stationary target and easier to deal with as long as the Survivor is not killed. He does not do this in Left 4 Dead 2, but it is still possible to force it to pound on an incapacitated Survivor, as long as you are willing to risk sacrificing a teammate. By standing close to the incapacitated Survivor (usually works better when he/she is between you and the Tank), the Tank will try to punch you, but since it is close to the incapacitated Survivor, it will be pounding the Survivor instead. With a melee weapon, you can kill the Tank before it can kill your teammate. This tactic is much riskier to do in Expert, as it can kill your teammate after two attacks.
 * Unlike the Witch, which can be avoided by simply running past her, Tanks will always become aggressive and attack as soon as you get in its range, even if there is a wall blocking its view, so you can't avoid setting off a Tank.

Survivors
The number of Tanks depends on the server preferences, the game difficulty and the "mood" of the Director. It is fairly uncommon that there is more than one Tank per chapter except on Expert in Left 4 Dead, in which it is almost a certainty that the Director will spawn two on most levels (however, in Left 4 Dead 2 it is again uncommon for there to be more than one Tank per level on Expert). If you have not faced a Tank in the previous level (in one that can spawn a Tank), be prepared to face one near the beginning safe room. In addition, sometimes the Director will spawn a second Tank if your team is cruising through the level and have already fought a Tank very early on. In all finales at least three Tanks are spawned, two during the initial rescue and one when the rescue vehicle is waiting. The only exception to this being Swamp Fever and The Passing, which feature two Tanks after the second Infected wave (or in the case of The Passing, after a set of waves that followed a single Tank spawn). Regardless of campaign, unlimited Tanks (one or sometimes two at a time) will spawn when the Survivors are making their way to the rescue vehicle. The Tank is heralded by a brief ceasefire in finales, where the Hordes will stop rushing (unless a Survivor has been covered in Boomer bile), allowing players to catch their breath. In other chapters there are generally fewer Common Infected around, almost making things eerily quiet - a calm before the storm. It's possible that this is because the other Infected have fled, as the Tank seems to eviscerate anything standing between it and its target without hesitation, although the Tank does not attack the Infected intentionally. Another possibility could involve the fact that the Common Infected have no real sense of self preservation, so fleeing from a Tank wouldn't be their instinct. Instead, the lack of Common Infected in this situation could simply be to balance the gameplay so that it's not too overwhelming.



Notes about the Rock Throw

 * The Tank cannot move while throwing a rock, giving Survivors an opportunity to melee it.
 * Each rock thrown will deal 24 damage to a Survivor if it hits on Versus mode.
 * You'll know when it is going to throw by the absence of the ground pounding noise.
 * Anyone can shoot the concrete out of the air, rendering it harmless. This method, however, is not always safe, as it takes more than a couple of bullets from an Assault Rifle to destroy the rock, and a shell from the shotgun at close range. The Hunting Rifle, if equipped, is perfect for sniping these rocks out of the air. It does require some practice, so you should not always try it.
 * An alternate choice if you have a Molotov is to throw it towards the Tank as it is throwing a slab. The Molotov should hit the slab and break it with the Molotov continuing on its original path (which, if landing in front of the Tank, is a plus). The other side to the rock throw is that once it is thrown, you only have a brief window of opportunity to shoot it or dodge it, depending on your distance from the Tank.
 * If the Tank is controlled by the AI, it cannot predict where a Survivor will run. Zigzagging will cause the Tank to throw the rock far from your current location. This does not apply on Expert difficulty, as the Tank possesses an increased aim and has an easier time predicting where you'll be when the rock reaches you. However, by moving in one direction when it is picking up the rock and then changing direction immediately after it has released it, it will most likely miss. This is because once it's been thrown it cannot change course. Note that this will not work if the Tank is very close.
 * You may be unable to dodge a rock if you are limping (i.e. when your health is below 40).
 * The Tank can throw rocks regardless of where it is standing, even if it's underneath a downed Survivor or if on a wooden support such as a bridge or walkway. The ground underneath it remains the same, despite having some of it ripped out.
 * If facing a player-controlled Tank with a melee weapon, try and trick the Tank player into punching early. Then hit him once or twice with your melee weapon before backing up. He may be so eager to hit you, you may back up out of his range as he punches, causing him to miss and allow you to attack again. This is an effective strategy, especially when someone else is doing the same thing. Be wary of the Tank's teammates trying to make you a sitting duck, and remember that you cannot use a melee weapon when grabbed by a Smoker (unless it is a Chainsaw) to free yourself. So make sure to have someone else using guns in the event if you should be immobilized by a Special Infected.

Infected
Occasionally, players are able to take on the role of the Tank in Versus mode. When the Director has given them control of it, the Tank has a frustration meter that depletes quickly as long as the Tank cannot see the Survivors. The frustration meter will stop draining when Survivors are in sight, but will not refill until the Tank hits the Survivors. This was employed to prevent players from camping away from the Survivors for long periods of time and using out-of-character strategies (i.e "sniping" the Survivors by throwing rocks and not actually fighting them). Once the frustration meter is depleted, control of the Tank is given to another player if available. If the second player's frustration meter is depleted, the Tank becomes AI-controlled. Also, when players are controlling the Tank, they can break down walls highlighted by yellow cracks. Though multitudes of Common Infected can break down the walls, as can other Special Infected, only Tanks can break through the beginning safe room door. There was an update for both the Xbox 360 and PC versions of the game where certain objects that can be punched/thrown (cars, dumpsters, etc.) are highlighted in red. The items highlighted in red usually instantly incapacitate a Survivor on impact (except in The Bridge finale where the cars only take out a large amount of health to balance gameplay due to the abundance of cars on The Bridge.)


 * Avoid crouching through ventilation shafts and windows after Survivors. You will move incredibly slow whilst taking damage and crouching (from weapons such as the Auto Shotgun especially), almost to a point where you will find it difficult to move at all. Although this problem has been addressed by Valve, it is never a good idea to move though an area where the Tank is forced to crouch or use the button to crouch while you are a Tank. Attack the Survivors through the window with rocks or, if they are in a vent, let your teammates flush them out.
 * Your rock throw is usually underestimated. With practice it can be devastating and deal a lot of damage to the group of Survivors quickly. As a rule of thumb, aim your reticule above, and perhaps ahead of, the target while throwing. Remember that rocks fly in an arc.
 * Even in close range, the rock throw can be effective because you can follow it up with a quick melee attack. However, if many of the Survivors are focused on you, you may sustain a significant amount of damage during the relatively long process of throwing a rock.
 * If a Survivor is running away for distance, you can slow them down with a well-aimed hit, especially if you cause them to start limping, allowing you to outrun and finish them off.
 * If you have a competent team and are well suited with tossing rocks, you can simply hide behind low barriers or up high and throw rocks at the Survivors while your teammates cause havoc. This tactic is often advised if the Survivors are in an area where they can flank you easily, have powerful weapons such as auto shotguns or melee weapons, Boomer bile, or Molotovs.
 * Be aware that if you use the rock throw, you are unable to move for a considerable amount of time. More often than not, a crafty player will take advantage of this and throw a Molotov/Boomer bile jar at you. If the Survivors have melee weapons, one or two of them - especially if one is weilding a chainsaw - can come up behind you and drop your health rapidly if not outright kill you. Keep this in mind if you plan on using the rock throw ability frequently.
 * Although you cannot punch through walls, certain walls allow you to throw rocks through them if you're hugging them.
 * A Tank can punch every two seconds. Keep this in mind when running at a group of Survivors, as during the time it takes for you to punch again, the Survivors may have already killed you.
 * There is also a half second delay between when you click to punch, and when you actually punch, so take that into consideration.
 * Even though the Tank has many hit points, a strong Survivor team can take it out without taking damage themselves.
 * Avoid attacking in the open at all if possible, because in the open it is much easier for Survivors to evade both your melee attacks and rock throws.
 * It is possible to assist Hunters who have already pinned someone, but the effort required to aim isn't worth it. The reason is that the Tank's attack will kill the Hunter (or any other Special Infected, for that matter) instantly.
 * On the same note, if someone else on your team is playing as a Tank, work with them, but give them a wide berth, as they could easily kill you by mistake.
 * If a Survivor is pinned by a Hunter, try to protect your teammate as by running towards the other Survivors. You'll want to either punch them as they try to run past you to save their teammate, or have them back off so that they cannot save their teammate. It only takes a Hunter a few seconds to dish out some serious damage.
 * If a nearby incapacitated Survivor is attempting to save their teammate from a Special Infected, you can use your body as a shield to give your teammate extra time to deal more damage. Although this can help, it works better when the incapacitated Survivor and trapped Survivor are the only two remaining, and it would probably be more productive for you to go after other healthy Survivors.
 * If a pair of your teammates have pinned a pair of Survivors, it may be a good idea to guard them from any Survivor attempting to play the "hero". This isn't often respected, but may be useful if a Survivor is attempting to press forward to save his/her teammates. When he/he turns the corner to find you there, this allows you to easily incapacitate them.
 * Use alternative routes where possible to "sneak up" on or flank the Survivors. Make sure the route isn't too large as to avoid your frustration meter from emptying. It isn't uncommon for a Tank player to get around the Survivors to attack them from behind, only to have his frustration meter empty on him as he is getting into position.
 * If you incapacitate a Survivor, immediately re-target another and prevent the Survivors from reviving the incapacitated.
 * If playing on a level where it's possible to punch Survivors off of the level, such as chapters 4 and 5 of No Mercy, do everything you can to knock them over; once they fall, there's no helping them. To do this, punch while try to aim the reticule upwards.
 * Using punchable objects effectively can save you health and time, and can effectively distract Survivors as they try to avoid the objects.
 * Most of the time, you can hit such an object from any side of your body. Use this to save time walking around objects, because you can just walk up against it and punch the way you need it to go. Additionally, you can aim upwards to throw things in an arc or toward the ground to have more control of the direction you punch it in.
 * These objects can also be moved to make a temporary barrier to slow or stop the progress of the Survivors.
 * You can use the barriers to stop the Survivors from progressing along a chapter. This is best done to block a safe room door. Another example is the sewers in The Parish - you can punch a car over the manhole at the end, or if a Survivor or two have gone into a room with one exit, you can barricade them inside with a dumpster, car, etc. This is usually frowned upon however, and it often means you cannot reach the Survivors or any others that managed to avoid the barricade escape, causing you to lose control of the Tank.
 * This has been patched. Objects hit by a Tank will disappear over time if the Tank does not hit it again within the time limit.
 * Punch Survivors in different directions to separate them.
 * If the Survivors are in an enclosed area, keep attacking one Survivor (usually the one with the lowest health) until they are incapacitated.
 * Be careful using the swing attack on Survivors in wide open, flat areas, as this merely gives them a chance to get away. Charge a Survivor you've whacked as soon as you whack him/her, and keep going in for another whack. It's a good idea to hit a Survivor towards something that will stop them from flying far away from you, so you can hit them again and again while they are down and trying to get up and shoot you. Be advised that this makes you a stationary target for other Survivors and even, if they're willing to sacrifice a teammate, throw a Molotov at you.
 * Always aim to divide and conquer if you're in a building or an area with many obstacles. Try to spread the Survivors out by hitting them behind large objects or knocking them out of windows. Separated Survivors allow for other Special Infected to attack and kill them.
 * If the Survivors can't see you, they can't shoot at you, meaning that you will take less damage during your rampage.
 * This helps Hunters to pounce on Survivors, or Smokers to grab Survivors, so they can't come to the group's aid or the group coming to kill the Infected that has them pinned or tied up, leaving you with one less Survivor to kill.
 * Do not attack an incapacitated Survivor if a Hunter, Charger, Jockey or a Smoker already has them locked in a bind. Doing so will more than likely kill your teammate and free that Survivor.
 * Avoid being set on fire as best you can.
 * Take notice at who has a Molotov before you approach, and avoid these players until the fire they throw burns out.
 * If you hit a Survivor you see has a Molotov, be sure to incapacitate them if you can.
 * If you see somebody who is about to throw a Molotov, change direction immediately! If worst comes to worst, use the rock throw to hit Survivors.
 * Fire alone kills a Tank after 30 seconds.
 * If you are set on fire, charge the Survivors. You won't have much time to attack, so every second counts.
 * If there's water nearby (like in The Boathouse Finale), dip in to put the fire out. This also works in The Sewer of No Mercy.
 * Go after any Survivors that are separated from the group, unless the others are extremely low on health. One gun on you is much better than three.
 * The March 11th update made it possible for the Tank to hit multiple Survivors at once. Previously, it was a viable defense when playing as the Survivors to group together in a small room or a corner. This was because the Tank could not hit more than one person at a time and would quickly be killed without doing much damage.
 * In the scenario that all of the Survivors bunch up and use auto shotguns, attempt to put as much distance as possible between you and them. Keep them in your line of sight (or behind good cover if you are good at rock throwing), and pick them off with a volley of concrete blocks.
 * You can also have a Spitter teammate run in and cause them to separate, allowing you to rush in while they are confused and disorientated to deal heavy damage before they realize you're attacking them. By then, you've possibly incapacitated one of them.


 * Unlike Campaign Mode, attacking an incapacitated Survivor will inflict only 24 damage per hit. Considering incapacitated Survivors have 300 health, it is much easier to simply incapacitate each Survivor one at a time. Choosing not to do so usually makes you a stationary target for everyone to gun you to death. You should really only attack an incapacitated Survivor if they are close to death or to force the other Survivors to come to you.
 * If your team has good communication in the above scenario, ask a Hunter to pounce on a Survivor while you distance the others. They will not be able to use a pistol while they're down since they are being hurt, and their team needs to deal with you first.
 * If you get the indication that you are about to become a Tank, and are currently an un-spawned Special Infected, try to immediately spawn that Infected near the Survivors. This way your team will have an extra AI-controlled Special Infected to help during the attack. Note that in some cases, if you spawn too far from Survivors, the Infected AI will idle and not attack.
 * At one time or another, when you are next to become the Tank, you might spawn right in front of the Survivors, letting them pick at your health. It is possible to have only half of your health by the time you gain control.
 * If this does happen, just charge at the Survivors and attack. Since the Survivors are already in a position to inflict massive damage, you could die as you try to run away, so it would be better to deal some damage to them before dying.
 * Beware of Survivors with bile bombs. When you are struck with one, your vision becomes impaired, and Common Infected will attack and slow you down until you either kill all of them or the bile effect expires.
 * Flying cars are your best weapon; they will incapacitate a Survivor instantly. This makes The Bridge easier for the Infected team. However, keep in mind that the cars on the bridge will only severely damage them, and will not cause instant incapacitation.
 * Use caution when hitting cars. If the car hits something in front of it, or if you walk forward while the car is airborne, the car may hit you and cause a small amount of damage.
 * During almost every campaign finale, the Tank is summoned at the disposal of the Special Infected team at least twice. It can be noted that in most of the finales in Versus, the completion of the second Tank confrontation in order to allow the rescue vehicles to arrive. As a result, the Infected team can gradually weaken and crush the Survivors by forcing/instructing the Infected player nominated as Tank to camp, making the finale's outcome one-sided and giving the Infected team the undeniable upper hand. However, this strategy is largely looked down upon by the majority of the online community.
 * The second Tank defeat requirement is more common in the Left 4 Dead 2 finales than the the original Left 4 Dead finales.
 * As unbalanced and unfair this issue/bug may be, a patch/update has not yet been released to resolve it.

Tank Tips And Tricks Gameplay
As a Tank, most of the time you're going to have to rely on yourself to kill the Survivors. Though the other Special Infected might help, they are not going to be able to distract them for long. Here are a few tips to get you started:

1) Try not to get in the range of mounted guns, as they eat away at a lot of health in a short amount of time. Either have a teammate eliminate the mounted gunner or find some way to get behind them and either force them off the gun to shoot at you, or punch them off. Doing such in The Plantation House is a great way to cause incapacitation or even death by punching them off the second story floor.

2) A Survivor often panics when they see a Tank. Look for this one and chase them relentlessly, unless of course there is a Survivor you are more likely to kill, such as a wounded or bile-covered one.

3) A Charger/Boomer/Tank team makes for a good mix. Get the Charger to bring the Survivor as far from the group as possible, then while the Charger is pummeling them, have the Boomer throw up on them, and the Tank make sure no interference comes from the other pesky Survivors. However, make sure to spread out beforehand, as the Boomer can explode and stumble the Charger and Tank. Also, if the Charger misses and hits a wall by the Tank and Boomer, it will stumble them. If you are more spread out before attacking, you cannot be stumbled by a mistake from your teammate(s).

4) If one strategy doesn't work, try another. Each opposing team will play differently from the last.

5) You will sometimes see the outline of the AI Tank before you take control. If you can, get near the AI before you assume control so you will have a better idea of exactly where you are on the map and also so you don't lose control of the Tank while trying to get your bearings.

6) In the rare case of seeing a Survivor coming at you with a revved-up chainsaw, bat them away as soon as they are in range. A Survivor with a chainsaw will kill you in four seconds, and if they are batted away, not only does it create some distance, but they'll have to rev the chainsaw up again, which can allow other Special Infected to incap/kill them.

7) If a Hunter or Smoker has a Survivor pinned in a narrow hallway or the other Survivors are grouped up in one place while the pinned Survivor is being killed, stand between the group of Survivors and the pinned Survivor. It'll buy invaluable time for your buddy to kill the pinned Survivor if the bullets are hitting you instead of your teammate. 8) If at all possible, wait for the rest of the Infected team to spawn and throw rocks at the Survivors at a place they have to go to. You may get lucky and hit some of them, which will reset your frustration meter and may also incap Survivors. While buying your team time to spawn, set up and ambush the Survivors. Only move from your spot if Survivors are throwing a Molotov, trying to get past you, or shooting firing/explosive bullets at you.
 * Good locations confirmed are The Park in the hedge "maze" or the alley leading under the highway to the trailer.

9) On Expert if you encounter a Tank, you can run back into the nearby safe room, shut the door and crouch behind it while pushing up against it by simply moving the analog stick forward. The Tank will be unable to break the door down, allowing you to shoot him while he tries to knock it down. Be wary of the Tank's rock throw, as it can still damage you through this method. This trick is only recommended when you are nearby the safe room you were in earlier, and if all of your teammates are dead. This means you will have to exit the safe room and move through the chapter until your AIs spawn.

Here are some links for you to use to find more tips.

http://www.youtube.com/watch?v=Akf-v_7FFQ0&feature=channel_page http://www.youtube.com/watch?v=j0RWVqboVjI