Left 4 Dead 2

Left 4 Dead 2 is a sequel to Valve Corporation's Left 4 Dead. The game made its world premiere at E3 2009 with a trailer during the Microsoft press event, and will be on both the PC and Xbox 360.

Like Left 4 Dead, the sequel will involve the aftermath of a apocalypse pandemic that creates a number of zombie-like human mutants, forcing the few survivors to fight their way through the hordes to extraction points, using safehouse along the way to rest and recover. Left 4 Dead 2 will be set in the Southern United States, starting in Savannah, Georgia and ending up in New Orleans, Louisiana. Four new survivors will be introduced, with their backstory provided in a similar way to the original through dialogue in the game. The survivors include Coach, a high-school football coach; Rochelle, a reporter for a local cable company; Ellis, a boy mechanic; and Nick, a gambler and conman.

Like its prequel, Left 4 Dead 2 is primarily a first-person shooter, with some cutscenes presented in the third-person or using pre-rendered movies. In the main Campaign mode, up to four players can play cooperatively during the five new campaigns, each with a number of chapters; the computer controls any survivors that are not being played. In each chapter, the goal is to reach a safehouse location after fighting through hordes of infected mutants; the final chapter in each campaign requires the team to reach an extraction point and defend it until rescue arrives. In this mode, the game is guided by the "AI Director", an artificial intelligence engine that monitors the players' performance and alters the scenario to provide more or less challenge for the players as they progress. In Left 4 Dead 2, the AI Director has been improved to encourage more participation by players, forcing players through difficult gauntlets to reach the extraction point, and the ability to alter elements of the level such as placement of walls, lighting, or weather conditions. The AI Director will also be improved to reward players for taking longer or more difficult paths through each episode by providing more useful equipment, such as incendiary ammo, along these riskier paths, and even alter elements of the levels to create varied paths based on the choice of these paths. Players will have access to more and improved weapons, including melee weapons such as a frying pan, an axe, baseball bat, and chainsaw. In addition to the infected from the previous game, there will be new classes; one is the Charger, a being that is able to temporarily stun the survivors by body-charging them. Existing types will have some modifications, including zombies that are immune to fire, and the Wandering Witch that roams the level until disturbed by the players.