Left 4 Dead pits four human playable or AI controlled survivors of an apocalyptic pandemic against hordes of zombie-like, aggressive "Infected". The Survivors' goal is to help each other make it through various scenarios to safety. The Infected are controlled by an AI that dynamically balances difficulty and mood depending on the players' progress and situation. In an alternate game mode, human players can control up to four mutated Boss Infected with special abilities and cooperate to stop the Survivor players.
To run Left 4 Dead on high graphics settings your PC will require at least a 0MB GeForce 7600 GT 256MB / Radeon X1800 Series 256MB with a Core 2 Duo E4600 2.4GHz or Athlon 64 X2 Dual Core 5200+ CPU. System memory required for Left 4 Dead is 1 GB performance memory. To be able to run at all you will need at least 1 GB system memory. Your graphics card will need to be capable of running DirectX 9. Recommended needs around a 15 year old PC to run.