GS: Multiplayer cooperative gameplay is a big feature of Left 4 Dead, but will you be able to play by yourself in some kind of single-player game? If so, in that case is it just your character solo, or will other members of your team be controlled by artificial intelligence?

MB: Left 4 Dead is built upon Turtle Rock Studios' next-generation AI technology. This lets us create a scalable game experience whether you play alone with AI-controlled survivors and infected, or online with and against human players.

GS: Could you go into detail about the multiplayer modes? It sounds like there's going to be cooperative gameplay against the AI, but also competitive gameplay, with one team playing as the humans and the other team playing as the infected.

MB: The game is designed to allow human players to drop in and out without adversely affecting the experience or requiring the scenario to restart. We have also taken steps to maintain the survivor's game experience even with the presence of human-controlled infected. Although the infected can "win" by killing all of the survivors before they reach the finale and escape, it doesn't feel like a traditional competitive game--it still feels very cooperative from the survivor side.

GS: What sort of weapons will be in the game? Are we talking about modern-day equipment mixed in with a few futuristic prototypes? And can we expect any kind of vehicular combat?

MB: For the initial release of Left 4 Dead, the game's arsenal consists of weaponry that you would be able to scavenge during such a catastrophe: handguns, hunting rifles, shotguns, even some homemade weaponry like pipe bombs and Molotov cocktails. We are planning to continue to create and release new content for the game via Steam, much as we have done for the Counter-Strike franchise. Over time, we expect the inventory of items in Left 4 Dead to continue to grow.