Set in a modern day survival-horror universe, the co-operative gameplay
of L4D casts four "Survivors? in an epic struggle against hordes of
swarming zombies and terrifying "Boss Infected? mutants. The Survivor
Co-op Game Mode is played out across four sprawling campaigns, set in
urban and rural environments. Each campaign has an over-riding team
objective, and is comprised of five large maps. The campaigns link
together to tell the story of the Survivor?s escape to safety. The team
of four Survivors may be comprised of 1 to 4 human players, allowing
for single player and multiplayer co-op games.
