"After Left 4 Dead came out last year, I spent many, many nights fighting the zombie apocalypse with friends and co-workers, going through the campaigns over and over again, and never getting bored of the experience. The teamwork aspect really brought something new to the game, and made it one of my favorite titles of 2008, in addition to my favorite shooter and multiplayer experience. Now that Left 4 Dead 2 is out, there are some new characters set on surviving massive amounts of zombies, but the core concept is the same: work together if you want to stay alive, and make it through each campaign as a team. Sometimes it's hard to give up that health pack you've been hoarding to assist your limping teammate, but you would want him to do the same for you, right? And maybe you can make a clean break for the safe house, but should you really leave anyone behind? These are the kinds of questions often raised during typical gameplay sessions of L4D and L4D2, and last night I got a taste of just how fickle my friends could be."