Valve officially announced Left 4 Dead 2, the sequel to the successful cooperative first-person shooter Left 4 Dead.
Left 4 Dead 2 was released for Microsoft Windows and Xbox 360. The game featured new campaigns, characters, and infected enemies.
The Mac OS X version of Left 4 Dead 2 was released via Steam, expanding the game's platform availability.
Left 4 Dead 2 was released on Linux, further extending the game's compatibility.
Valve began supporting community-created campaigns for Left 4 Dead 2, enhancing longevity and player engagement.
A highly contagious infection rapidly spreads across the United States, turning humans into aggressive infected.
Government and military forces attempt to contain the infection and evacuate survivors, but fail due to overwhelming numbers of infected.
The four main survivors—Coach, Rochelle, Ellis, and Nick—come together amidst the chaos in Savannah to find rescue and safety.
Survivors fight through infected-filled streets and a mall to reach a military evacuation point that has been compromised.
Survivors traverse rural and swamp areas after finding the city evacuation failed, facing new challenges including booby traps and infected wildlife.
Survivors reach Dixon, where they learn of a possible evacuation at a nearby airfield.
The survivors fight through infected to activate a beacon at the airfield and signal rescue planes.
Rescue planes fail to arrive immediately, forcing survivors to find other ways to stay alive and continue seeking rescue.
Intelligence reveals that there may be a naval evacuation off the coastline, prompting survivors to head towards the ocean.
Survivors battle through infected in the city and coastal areas to reach a boat for escape.
Survivors successfully escape aboard a naval boat, leaving the infected-infested mainland behind.
