Evil lurks within this game, pure unremitting horror the likes of which you have never seen before in the medium. It can induce terror and panic at the drop of a hat, capable of an unfeeling, unyielding pursuit of one goal - to scare the shit out of you. This being is not a zombie, it doesn’t have gnashing claws or a high pitched wail. It doesn’t even exist, really. It goes by one name, one singular title which sums up the extent to which it will take over your game and cause you to lose all hope and sanity. It is the Director - a horrible amalgamation of George A. Romero and Skynet.

On the face of it, Left 4 Dead is actually incredibly mundane, featuring a tiny selection of weapons which all function in ostensibly the same way and a small selection of maps which all play out in a similar fashion - get your team of four survivors from point A to point B without dying. The four playable characters are, from a gameplay view, identical in function, and even the enemies are all built around the core concept of big teeth and long claws. Play with AI companions or with humans, it is your choice. They can even have the AI temporarily take over for them if they need to go out for a moment, able to regain control instantly. But zombies are not new, and shooting zombies with shotguns is just as old. So what is the draw here?

The draw here is Valve, almost incapable of the mundane, and what they have wrought here is something so special it has to be experienced firsthand to be believed. The Director, the all powerful AI that manages every single aspect of the game, has a simple aim; to ruin your day constantly. It has complete control over the spawning of enemies, the types which are included, the amount of them which appear, and from where. The music tempo and volume, the lighting of the environment, the pacing of the level and the set pieces; everything which you would expect to be hand-placed by a level designer at Valve Towers is handled by a computer. Your computer. And you will come to hate it.

Let me paint a picture here to illustrate this. The first ‘movie’ in the game is No Mercy. The objective is for you and your three friends to fight your way through an apocalyptic cityscape to a hospital, find your way to the roof and escape via helicopter. Simple, right? Wrong. In fact so wrong it quickly becomes apparent just how much of an asshole the Director is, if that is even possible. You might start and the street is empty, go halfway down and a dozen zombies jump from a rooftop onto your group. The music ratchets up and everything is so far so Land of the Dead. But the next time you play, nothing might happen. You expect a shitstorm of brain-eating horror but get silence. You continue on and no horde out for blood, no high pitched strings, no flash of lightning. Nothing. This is because the Director chose not to have that happen, and you should be glad when this happens. But it goes much further than that, springing traps for you, trying to single out members of your group, the weaker ones who have been using all the health kits and have the worst accuracy. They are the catch of the day and often the Director purposely singles them out. It’s a cruel fate that makes you get good at Left 4 Dead very quickly. If you don’t climb that learning curve, you die.

The Director is measuring the experience, meaning, unusually for a shooter, it never really gets old, despite the slight repetition in maps. You can literally never have the same experience twice, always relying on the omnipresent voice in the sky to determine when the metaphorical shit hits the fan. And it isn’t a case of just mixing things up a little between set pieces, it is actually a wholly new gameplay moment. For example, at the mid point of one movie, Blood Harvest, you enter a vast cornfield layered in fog, abandoned tractors and empty farm buildings scattered all around. First time I played this scene we trudged to the middle and then were set upon by three hundred rampaging zombies from all directions. It was an intense, heart-pounding action sequence that resulted in a pile of corpses two foot high around the base of the barn exterior. Thrilling, exciting and tense. But the next time it was quiet, the music was right down and all you heard was the screeching birds darting out of the crops and the distant hum of vehicles. Nothing happened. No sudden ambush, no pulse pounding fight for survival. The tone of the game was completely different. Eerily silent, and much more tense. This effect is replicated throughout the game, allowing these vignettes of action or suspense to be conjured from anywhere. And with an evil Director controlling the whole thing, you could be looking one way expecting an attack and then find three dozen undead have crept up behind you, or snatched your best friend and pulled her halfway across the street and up to the roof with a giant tongue. Because it is unpredictable, it always manages to create pure fear and panic.

Left 4 Dead’s greatest success is the way it manages your experience. Sure enough, the environments have a very Source Engine look to them and the level of detail is somewhat lacking compared to recent genre highlights, but the endgame here for Valve is the fun, meaning eye candy is often sacrificed for function, and object placement is controlled by necessity. You feel like the whole time you are playing, you are in the hands of people who know what they’re doing. You never feel cheated by the AI, because it is never unfair. Work together or die, it is that simple. Of course there is a versus mode, and a variety of difficulties and map selection, allowing you to play the undead side and unleash your hate on your human counterparts, but this unfortunately breaks the formula, because the Director is not trying to win, it is trying to enhance your experience, whereas other human beings don’t care for how you feel, they just want to bite your nuts off.

Have Valve, in creating the Director, made themselves somewhat redundant? This AI, this non-existant entity, has displayed more talent and skill in designing a game than the vast majority of the development houses out there. It knows when to ramp up the action, and when to give you a breather. It understands pacing and difficulty at an incredibly advanced level and will always provide a thrilling and enjoyable game. And it is always watching…