Achievements

Left 4 Dead includes achievements for Steamworks and Xbox Live. There are 73 achievements in all for the PC version of Left 4 Dead, but only 65 for the Xbox 360 version; the Outbreak achievement is not in the Xbox 360 version of the game and Survival Pack on Xbox 360 adds no new achievements due to technically being only a patch, not a DLC. There are currently 100 achievements for the PC version of Left 4 Dead 2 (one of which, Valve Gift Grab 2011, can no longer be earned by normal means) and 65 achievements for the Xbox 360 version.


 * Survival Pack adds 7 new achievements to Left 4 Dead for the PC version only.
 * Crash Course adds 10 new achievements to Left 4 Dead.
 * The Passing adds 10 new achievements to Left 4 Dead 2.
 * The Sacrifice adds 5 new achievements to both Left 4 Dead and Left 4 Dead 2, and for the Xbox 360 and PC as well as Mac.
 * The Cold Stream update added 2 new achievements to Left 4 Dead 2 called Stream Crosser and Connecting Fights, although the latter achievement is actually keyed to the conversion of the Dead Air campaign in Left 4 Dead 2. As a reward for 60,000 players earning the Connecting Fights achievement, Valve released a beta version of the Blood Harvest campaign for Left 4 Dead 2.
 * A special holiday-themed achievement, called Valve Gift Grab 2011 — L4D2, was added to the PC version of Left 4 Dead 2 for a limited time in late December 2011.
 * The achievement Good Guy Nick is achieved by surviving a campaign with players who obtained their copy of game during free weekend.
 * The Last Stand adds 30 new achivements to Left 4 Dead 2.

Note: Since the Crash Course update, achievements cannot be earned with cheats turned on (sv_cheats = 1), however, one way is to play on Versus mode with everyone helping each other to get achievements. Another easy way to obtain achievements is to create a server in order to exploit the console commands.

Survival Mode
None of the Survival Achievements are present in the Xbox 360 version of the game since it is a free DLC.

Miscellaneous
Achievements that don't fit anywhere else.