GamesRadar writes: "Along with the PC Gamer staff, I just can't get enough of 2008's multiplayer game of the year, Left 4 Dead. The formidable team of Stapleton, Lahti, Chan, and Will Smith (of Maximum PC fame) has exhausted all of the game's missions, and we've reached a point where we can complete any campaign on the Advanced difficulty setting with relative ease. But to get to this point, we've had to teach ourselves some important new lessons and play habits for cooperative play. After all, the teamplay tactics of Team Fortress 2 don't all apply in a pure co-op challenge, and Left 4 Dead is not your ordinary Gears of War-style co-op game. And if you're starting on your way through a campaign on Expert difficulty with a squad of bunny-hopping Counter-Strike junkies, you're not going to get very far before the team breaks down. So to avoid the blame game, here are the rules that every player should master before embarking on a serious session of zombie killing."