In honor of Halloween...Urban Dead is a web-based persistent world game; your character is either a "zombie" or a "survivor", two factions eternally trapped in an urban warzone. You gain experience by fighting, you buy skills when you level up, you have "action points" that accumulate over time.
That much is easy to say, but there are surprising depths to Urban Dead. It's worth playing for a while, and it's even more worth seeing how other people play. There are some interesting aspects of the game when you start out, like: Which skill should I buy first? How do I survive as a newbie zombie? But many players have all their skills bought, and that's where you start getting into the really interesting strategies.
If you read about game design at all, you'll eventually come across something about "second order design". The idea is that game designers create experiences indirectly; they create rules, the rules delineate the players' actions, and those actions lead to experiences that are engaging in some way. The designer attempts to create rules that lead to the kind of experience they're trying to engender. A related concept is "emergent behavior", which arises when rules interact to encourage new actions.
The designer of Urban Dead, Kevan Davis, has set down a number of simple rules delineating what someone could do during a zombie apocalypse. The persistent nature of the game implies that there have to be some times when you're logged off, but your character is still around. Zombies roam the city searching for survivors, so if you're a survivor, you want somewhere to hide. Therefore, survivors hole up in buildings and barricade them. If a building is at all barricaded, a zombie cannot enter it; they can attack the barricade, but success is dependent on a die roll and tends to take a lot of AP. Survivors can enter buildings unless they're "heavily barricaded" or above. Therefore, newbie survivors roam about looking for buildings that are barricaded well but not completely.
From the other point of view, a zombie wants to find a likely building, tear down the barricades and feast on the brains of those inside. However, if you're one zombie against a building with 10 survivors, they're likely to blast you with a shotgun and repair the barricades as soon as they log in again. You could get a dozen friends together and coordinate in real time to break into a survivor safehouse; players certainly do that. But there's another, more interesting way...
When a zombie is face to face with one or more survivors (which usually means they've broken into a building), they can use the skill Feeding Groan. Everyone within a radius of several blocks will hear the groan and its position. Zombies that hear this groan know that someone broke through a barricade--that the survivors are, for that moment, vulnerable, and that a fellow zombie is asking for help.
The result is decentralized organization. Like ants or slime molds, the zombies swarm in where there's a vulnerability. Nobody said "Attack this building"; even throwing 10 zombies at a building might not work if it's heavily barricaded, or if there aren't any survivors inside! But Feeding Groans allow the zombie hordes to organize themselves without a central authority. Each zombie is acting on its own initiative, but for the greater good (in a zombiecentric sense).
From a survivor's perspective, one zombie breaks through and starts groaning--and suddenly a huge fucking zombie horde bursts into the room and totally tears shit up.
Sounds kind of like a zombie movie, doesn't it?
(And hey--those 10 friends coordinating their invasions through IRC or messenger? If they start groaning, they can attract huge numbers of zombies into their little crusade.)
There's more to the game I haven't even touched on. For example, if survivors are killed, they rise as zombies...and some skills let survivors resurrect zombies into survivors. This has fascinating implications for how you play your character; Do you like being a survivor, or a zombie? If you die as a survivor, do you try to be the best brain-eating zombie you can, or do you try to get resurrected? If you're a zombie and someone revives you without your consent, do you just jump off a building to "die" and become a zombie again?
If you're at all interested, you don't even have to play the game, you can poke around the Urban Dead Wiki. It's filled with strategy suggestions, roleplaying tips, humor and all sorts of crazy stuff produced by the (extremely passionate) UD community. Just skimming through will show you what can grow out of a few simple rules.
