Nearly twenty years ago Richard A. Bartle, co-creator of the first Multi User Dungeon (MUD) the precursor to the Massively Multiplayer Online Game, wrote an article entitled "Hearts, Clubs, Diamonds, Spades: Player who suit MUDs". Even today the classifications he set forth still hold true when examining the types of player who play World Of Warcraft and other MMORPGS.

This taxonomy can also be applied, with some modifications, to any multiplayer environment. There will always be those players who value winning over anything else, the Achievers, the Diamonds. Or those who simply enjoy the experience of playing with others, the Socialisers, the Hearts.

Playing Left 4 Dead recently it struck me that the characterisation of each of the four survivors seemed to conform to one of these four player types.

Bill, is the grizzled veteran, the professional. He knows what he's doing and will get the job done with little fuss. The goal is to win (to survive) and anything that doesn't increase his chances of winning is not worth bothering with. He'll crack the occasional joke to break the tension but ultimately he's the responsible adult of the group. He's the Achiever.

Zoey, is the horror film fanatic. Like Bill she knows the rules, she's seen all the films, she knows what happens when the dead start to walk the Earth. At the same time she's always ready to lend a hand, and support the group. On her own she might survive but what's the point is she's the only one left? She's the Socialiser.

Francis, is the misanthrope, the cynic. He might know the rules, but you can never be sure, as he's perfectly willing to break them for his own benefit. He's good to have around when the horde descend on you but if he has to he'll leave everybody else to die, after all what does he care, he hates everything, so don't expect him to care about you. He's the Killer.

Louis, is a little out of his depth. Everything is an experience, everything is fascinating and new and exciting. He's not sure of the rules, but fascinated in finding out what they are, and have some fun along the way. He's just as liable to accidentally shoot you in his excitement as he is to shoot the shambling masses of undead. He's an Explorer.

The nature of Left 4 Dead, is such that Bartle's original classifications don't fit exactly, with no explicit reward beyond survival Achievers cannot really be singled out by their desire to accumulate wealth or experience and the cooperative nature of Left 4 Dead means that Killers cannot be solely identified by their desire to impose themselves on others.

A more appropriate way to define the different play styles of Left 4 Dead, and a method that works for other multiplayer titles, is to examine where players fall on two axises defined by their tendency towards a focus on themselves (Cooperation) over others (Competition) and their attitude towards the rules of the game.

Returned to out Left 4 Dead example, Francis and Bill style players have a focus on winning, on competition and success. Whereas Louis and Zoey style players have a focus on the act of play itself and their experience with others.

A team of prodominantly Bills will almost always get to the end of a campaign, they are effecient, reliable and proactive. They have a plan and they'll execute it, even if the whole experience might seem a little joyless to the outside observer.

A team of Zoeys, might get to the end of a campaign but if they do everybody will get there together, as a team. Like Bill they are proactive and reliable, but they are also willing to risk themselves for the good of the team.

Much like a team of Bills, a team composed of a majority of Francis' will get to the end, but it might be messy. They'll keep each other alive as long as they need to because an extra weapon and extra pair of eyes is always useful, but come the climax it's everybody for themselves.

As with a team of Zoeys a team with a high percentage of Louis' might get to the end or they might all die horribly, either way it'll be an interesting experience and something will be learnt, even if it's just when not to throw a Molotov Cocktail.

With a little modification this taxonomy can be used to differentiate the types of players in other multiplayer games, or potentially even predict the outcome of team games, by examining the make up of players within each team.

Oh and by the way, I'm a Zoey.