Left 4 Dead Cheats

Select Options->Keyboard/Mouse->Allow Developers Console.  During gameplay, press [~] to access the console. Type Sv_Cheats 1 and then press [Enter] to enable the cheats. Then enter the following codes:

Cheat

Code

100 health give health
Auto shotgun give autoshotgun
Full ammunition give ammo
Full health give health
Hunting rifle give hunting_rifle
Invincibility god
No clipping noclip
Molotov cocktail give molotov
SMG z_spawn weapon_SMG
Pistol give pistol
Spawn boomer z_spawn boomer
Spawn hunter z_spawn hunter
Spawn infected X (X = hunter or boomer or smoker or witch or tank) z_spawn X
Spawn smoker z_spawn smoker
Spawn tank z_spawn tank
Spawn zombie horde z_spawn mob
Unlimited ammunition sv_infinite_ammo 1