['The Game Anthropologist' is Michael Walbridge's regular GameSetWatch-exclusive column looking at gaming communities and subcultures. This week he argues that Left 4 Dead represents bigger changes for co-op gaming than, say, Gears of War 2.]

Co-op gaming is older than most gamers; while examination of co-op gaming has always existed (Co-Optimus.com, for instance, is an entire site dedicated to co-op gaming), many recent releases have prompted players everywhere to think about the state of co-op and its capabilities.

In fact, one might argue that Epic's Gears of War 2 is the culmination of what co-op gaming always was, while Valve's Left 4 Dead and its unique game mechanics are truly a step toward the future.

Gears of War 2 followed a formula, and did it very well. It is a shooter complete with content, a campaign, and various multiplayer modes. One of these modes, horde mode, brings the players together in co-operation, a first for a title like Gears of War.

In Gears of War 2, co-op is doing what it has always done: adding even more value and longetivity to the game, creating incentive not only for consumers to buy the game, but to keep it; also, the more players that keep the game, the fewer that have the option to buy used. From the side of production, there was always the incentive to provide co-op modes so that more people would purchase the game.

Turtle Rock and Valve, on the other hand, saw that co-op could have other uses; instead of making co-op an added feature, why not make significantly different design decisions based on co-op principles?

They are not necessarily the first to do this (Army of Two attempted to do the same thing), but they are the first to design a full-priced game around co-op while achieving impressive sales and, at the same time, omitting traditional content!

Most co-op to this point has simply been meeting the need for players to play together while not playing competitively. The players could thus experience the content together. Left 4 Dead does not have traditional content or competition (if Valve achievements are any measure), yet sold well and is still highly-played. Why?

It could almost be called an MMO in a box; you are out in the hostile world, monsters anywhere, and you don't know who you will have to engage these monsters with. Left 4 Dead can only be conquered if the players have the level of cooperation that a dungeon full of huge ogres and dragons requires.

And this time, it's zombies and shotguns with FPS mechanics instead, and with no subscription fee and leveling. Many of the trappings still apply, though.

As for content—well, there's that movie; the writings on the walls at the beginning of each level are interesting to read. But still, there's no ending, or cutscenes, or anything.

There is a game world here, but those who have cried desparately for appropriate "interactivity" have gotten it—each time you run through this game, the experience is highly different. And it's not just the A.I. director placing every zombie randomly, either.

Because in Left 4 Dead, you will often need to play with random players, which is what would likely happen if a terrible disaster like a zombie infection were to occur. They may or may not cooperate, they may wish to lead or to follow, they may wish to go first or last, they may be gung-ho or they may be too cowardly.

Even technology that creates "narrative dissonance" keeps the immersion complete; the question of whether or not the player has a mic or not is just as important as whether he will heal you with his sole first aid kit -- or whether he has the ability to use a pistol to pick off the hunter that has pounced you and is rending your flesh, far away from any other team mate.

Friends or strangers, every single time you play you are re-experiencing a disaster and the teamwork (or lack thereof) that it requires.

It seems that for some, Gears of War 2 is replacing Halo 3 as the new golf. Maybe it should be Left 4 Dead instead, since you learn about the other players much more quickly. Each time it's a new tale, pleasant or not.