Okay, so I'm sure that by now you know the basics about how you're not supposed to act while playing Left 4 Dead, and you know that it's not quite your traditional shooter. So you're aware of how to not be a complete doucherocket, but I'm here to talk about the tricks I've learned to make it look like you really know what you're doing. Being that the game is so heavily focused on cooperation, a lot of these tips will be for groups of survivors rather than you as an individual, so they might not be of much use to you in public, quick game sorts of situations with a group of strangers, but if you and your buddies want to get through Blood Harvest on Expert, this is stuff you'll want to know.

So what are the best ways to convince your friends you know how to play Left 4 Dead? Read on to find out.


Keep it Tight, Bro



Step one is to always move as a unit. Yeah, that seems awfully basic, I know. You learn very early that running off down a dark alley by yourself is only a good idea when you really want to show the contents of your rib cage off to your teammates. But we're not just talking about being around one another, we're talking about performing every single movement together. When zombies are about, keep one or two people on point, crouching to allow your buddies to shoot over you, maximizing efficiency and minimizing friendly fire. Your fourth should remain in back, keeping an eye out for ambushes from behind and watching for the special infected that his mates might miss through the mass of gore in front of them. When investigating small side rooms for supplies, your six man will want to remain outside to warn of any surprise attacks from the horde or an errant hunter. This person's most important task, however, will be shutting doors. No, really. When moving through interior environments, keeping doors shut means the only way zombies in those areas can get to you is by noisily and conspicuously breaking them down, giving you more than enough warning to dispatch them. This is especially useful in versus mode, since the enemy team will almost invariably get a smoker on you from behind if you fail to close all the doors in the stairwells during the first chapter of No Mercy. So know your role in the group and stick to it, and you'll find that you feel much safer. Until the Tank shows up, anyway.


Know Your Surroundings



You might remember that, in some of the game's initial hyping, the designers complained that other games that took you repeatedly through the same set of maps became extremely boring and predictable once the players learned enemy spawns, supply drops, etc.. Valve's solution was to have all of that stuff determined by the AI director, making it a new experience every time, and thus your previous experience with a level would be meaningless.
Well, it worked, for the most part. It is next to impossible to know exactly where the next horde of zombies will come from or where you might find another bottle of pills, but that doesn't mean previous experience with the level is pointless. There are a limited number of locations your supplies will spawn, so you've got to learn where to check and when. Keep track of where you found that pile of pipe bombs. It might not be there next time you play the stage, sure, but it is one possible spawn point. This is especially important with your primary weapons, since there are only a few possible places they'll turn up, and you'll typically only get one drop per chapter, so if you skip over it you'll be shit out of luck. Pistol spawns are also important to keep track of. They might be more common, but when Bill is getting dragged off by a smoker and all you've got is a combat shotgun, you'll be glad you picked one up.
The other important part of knowing your surroundings is knowing where to take cover when the shit hits the fan. You should always be aware of the closest 'closet' space; somewhere your team can cram into that has a very limited number of entrances. If someone gets boomered, staying out in the middle of the street is never a good idea. Know where your side rooms are and when to pile in. This also means you have to take the time to investigate the areas around your 'hold-up points', those times when the game flashes 'Prepare to fight the horde!' across the screen. There are almost always better places to hold out than the one the map seems to have set up for you. For example, there are no fewer than three fantastic closet spaces for the final assault of No Mercy. You'd never know that from the way most people play it, since the obvious way to do it is to use the rooftop with the minigun, but you're actually much better off huddled in one of these closets than out in the open. That is, until the Tank shows up.


Melee



There's a reason melee is bound to the right mouse button. You should be using it frequently. It is without a doubt the single best way to keep rushing hordes at bay, reduce friendly fire, and even deal with the special infected. There is never a bad time for a melee attack. Hunter pounced Francis, but you don't want to replace his midsection with a clip of M16 rounds? Cold clock that son of a bitch and shoot him while he's stunned. [Author's note: I lied, this actually isn't an issue. Survivors are entirely immune to friendly fire damage while pounced. Same goes for survivors constricted by smokers, so fire away! Just watch for when they finish the 'get up' animation.] Smoker is dragging Zoe off, but has cleverly hidden just out of sight behind some trees? Melee Zoe to break the hold, then hunt the smoker down before he recharges. Boomers are also heavily staggered by a melee attack. This is literally the only way to deal with them when they get too close. But here's the best thing about the melee:
You can melee while reloading. This is absolutely invaluable, particularly if you like using shotguns. When you run out of shells during a mob rush, you'd better just mash that right button as fast as you can till you're reloaded. It isn't flawless, and you're liable to be hit once or twice, but it's better than trying to retreat and ending up by yourself somewhere to be eaten.
Just don't melee the Tank.


Keep an Eye on Your Teammates



I know you're probably sick of hearing it, but your team IS the only way you're going to survive, so their health is just as important as yours. Keeping track of who has what, when they need a health pack or bottle of pills, or when they're incapacitated is an absolute necessity. Keep in mind that when the color of the health bar changes, so does the speed at which that player moves. You're going to have trouble speeding the group around a witch when Louis is hobbling around on two broken ankles.
Also important to note here is weapon choice. This is going to depend partially on the map, but you generally want a good balance of firepower. That's going to mean two shotguns and two SMG's for early levels, and a similar split with the second-tier weapons. But like I said, keep the level in mind when picking your guns. Don't just go with the auto shotgun because it's your favorite. They work great on interior stages like No Mercy, but outdoor levels like those found in Death Toll and Blood Harvest call for at least one of the survivors to come equipped with the hunting rifle. Try to balance Molotovs and pipe bombs whenever possible, as well. Always watch those indicators to see which of your teammates have what, and plan accordingly, because if the Tank catches you without a Molotov, expect to become intimately familiar with his fists in a rather short period of time. Because in case you haven't figured it out...


Tanks are Assholes



Seriously, though, Tanks fuck everything up. They have an uncanny ability to make you forget absolutely everything about how to actually play the game in your mad scramble to escape the section of sidewalk hurtling towards your head. Very honestly, I'm not even sure I'm the one who should be giving advice on these guys considering that my record going up against them has been... less than stellar. I can, however, tell you about strategies I have seen work out, usually after my corpse has been sufficiently splattered across the pavement by that meatfisted shitbasket. First of all, don't let him scatter you. If you panic and retreat into the nearest side room, he's just going to pick off your teammates one by one and you'll be up shit creek in no time. There's always the ol' "throw a Molotov and run like hell" strategy that works in many situations, just make sure you can put space between you while you wait for the flames to take the desired effect. If you're unlucky enough to encounter a Tank near the start of a level, it is also advisable simply take cover in your safe room, although I've heard scattered reports of Tanks breaking down safe room doors, so try it at your own risk. If your team is healthy enough to move quickly, (and assuming you won't have to deal with other infected harassing you at the same time) your best bet is going to be swarming around him in such a way that he'll constantly change his mind about who to rush at in a technique known as 'kiting'. He'll twist around and scream at each of you in turn while you pound shotgun shells into his chest. You can also use this tactic to move your team around him to make a mad dash for the safe house, assuming you're close enough. Of course, safe houses are not always the goal. Sometimes you've got to get rid of the Tank before rescue can arrive.
As douchey as it sounds, the most reliable way I've found to get rid of the Tank is to exploit his crummy path finding AI. Tanks have a bad habit of getting stuck in window frames, slowing them down much more than they do survivors. It's especially problematic if he tries to switch targets or directions mid-window, so use that to your advantage. They also encounter similar errors with some frequency when dealing with oddly-shaped props and set pieces, so watch for that whenever possible. If there are other suggestions for taking down Tanks (you know, besides 'shoot at it until it dies'), throw 'em in! I'm listening.



That does it for today's tips. Take these to heart and you'll be snagging the What are you trying to prove? achievement in no time. Incidentally, if you need someone to help you out, feel free to hit up me or my bros any time you like! We're always up for a game.
You might have noticed that these were all survivor tips that work best in campaign mode, so watch for a How to not look like an idiot in Left 4 Dead's versus mode sometime in the future. Till then, go kick some infected ass. I'll see you out there.