The following is a history of updates applied to Left 4 Dead. The updates, when on the PC version of Left 4 Dead, will be applied automatically when you restart Steam, and on the Xbox 360, you will be prompted to update the game when you start it up—however, this only happens if you have Xbox Live. The list goes from the most recent at the top, and the earliest at the bottom. These are only the specific changes made to Left 4 Dead itself. Note that the PC version gets the updates first, and that the Xbox 360 version gets all of the updates to that point in time in a pack. Due to this, it's possible that some of the more recent updates have not yet be released for the console version.

November 1, 2018[edit | edit source]

  • Dev command 'director_log_scavenge_items' can only be executed by the server.
  • Protect against invalid map displacement data.
  • Fixed official servers allowing clients to load custom content in competitive modes.

June 6, 2018[edit | edit source]

  • Fixed a potential remote code execution exploit.

November 30, 2017[edit | edit source]

  • Security and exploit fixes.

August 2, 2017[edit | edit source]

  • Fixed a new bug causing some items to not transition between levels.

May 30, 2017[edit | edit source]

  • Fixed a potential remote code execution exploit.

January 31, 2017[edit | edit source]

Additional fixes to prevent malicious servers from executing restricted console commands on clients.

January 27, 2017[edit | edit source]

  • Fixed a client crash in weapon sounds.
  • Fixed a bug that allowed malicious servers to execute restricted console commands on players.
  • Fixed a bug that allowed malicious servers to prevent players from executing console commands.

March 24, 2016[edit | edit source]

  • Fixed exploits that could allow remote code execution.
  • Remove forced shutdown when ctrl-alt-del is pressed.
  • Protect against a reported crash caused by a map name parsing failure.
  • Protect against a reported crash when returning to a lobby.

February 23, 2016[edit | edit source]

  • Updated binaries to improve crash reports.

February 18, 2016[edit | edit source]

  • Fixed an exploit that could allow remote code execution.

February 1, 2016[edit | edit source]

  • Fixed two exploits that could allow remote code execution.

May 20, 2014[edit | edit source]

  • Fixed the game failing to launch on some versions of Mac OS.

May 13, 2014[edit | edit source]

  • Enabled SteamCmd depot for dedicated server operators.
  • Fixed an exploit that could allow clients to transfer blacklisted files to and from the server.

5 Dec, 2012[edit | edit source]

  • Fixed a potential crash in the client shadow manager
  • Fixed the game and tools not launching on machines with 16+ CPUs.
  • Enable controller navigation of menus to support Big Picture mode.

22 Aug, 2012[edit | edit source]

  • Fixed a crash when attempting to play Single Player
  • Fixed a possible buffer overflow in localized strings
  • Fixed a networkID exploit that allowed players to avoid getting banned
  • Fixed some images not rendering correctly on the dedicated server welcome screen

Mar 1, 2012 (SDK)[edit | edit source]

  • Fixed the preview window in modelbrowser.

October 7, 2011[edit | edit source]

  • Fixed off by one bug when processing entity packets

March 10, 2011[edit | edit source]

Left 4 Dead

  • Added support for raw mouse input

December 4, 2010[edit | edit source]

Left 4 Dead

  • Fixed voice recording intermittently stopping on Mac OS X.
  • Fixed MP3 playback not working on PC.

November 2, 2010[edit | edit source]

Left 4 Dead

  • Fixed achievements getting awarded incorrectly if you had previously played on a PC (Mac only).

October 27, 2010[edit | edit source]

Left 4 Dead

  • Added Mac support for Left 4 Dead.
  • In Versus mode Tanks will spawn in stasis until a human player takes over. Tanks in stasis are invisible and invulnerable, and won't move or attack.
  • Tank speed is no longer reduced when on fire.
  • Allow players on the Infected team to manually spawn during finales.
  • Added a vote option toggle All-Talk.
  • Any Special Infected that causes a Survivor to stumble into a "ledge hang" situation will receive 50 points.
  • Bullets that first pass through an infected character before striking a Survivor are now ignored as friendly fire
  • In Versus mode car alarms will now trigger anytime a Special Infected pulls or stumbles a Survivor into an alarm car.
  • Protected console commands that can be used to lag or crash servers.
  • Menu music no longer plays automatically on startup.

October 15, 2010[edit | edit source]

Left 4 Dead

October 8, 2010[edit | edit source]

  • Fixed Linux dedicated servers failing to run in a path with uppercase characters

October 7, 2010[edit | edit source]

  • Fixed demos crashing on load

October 5, 2010[edit | edit source]

  • Fixed a few third person camera cheats.
  • Added VPK audio cache support.
  • Added "The Sacrifice" content.
  • Added Versus Multi-Map Scoreboard
  • Added the L4D2 Mounted .50 Cal

September 5, 2010[edit | edit source]

  • Fixed audio client concommands that could lag a server.
  • Fixed a remote DLL loading exploit (MS KB2264107).
  • Fixed a crash when disconnecting a rcon connection due to an invalid password when multiple sessions were already connected.

February 24, 2010[edit | edit source]

  • Fixed an issue where servers wouldn't relist after the master server was bounced.

December 18, 2009[edit | edit source]

  • Teams that prefer listen servers will no longer be matched with teams that prefer dedicated servers
  • Official dedicated servers are now preferred when searching for team matches
  • More populous lobbies are now preferred over less populous ones when searching for games
  • Players who crash or have failed to load are no longer banned if they have been kicked
  • Fixed exploit allowing players to end games prematurely using the 'outtro_stats_done' console command
  • Reduced Dedicated Server max search ping to 150 ms
  • Fixed a common crash

November 10, 2009[edit | edit source]

  • Fixed a crash related to a Crash Course achievement
  • Fixed an issue where bots and computer controlled special infected were being reported via "View Game Info"
  • Added Team Versus 4 on 4 competitive matchmaking

October 10, 2009[edit | edit source]

  • Fixed campaign image not updating correctly when creating a lobby
  • Increased the reliability of the Steam Group server display
  • Made mm_dedicated_search_maxping available to allow users to set the maximum acceptable ping for a dedicated server. The default has also been lowered 150ms, down from 300ms
  • Fixed an issue where rescue closet doors could be opened in Crash Course in Versus mode

September 30, 2009[edit | edit source]

Left 4 Dead (PC):

  • Item density calculation corrected for Versus games
  • Fixed weapon density in Crash Course
  • mp_gamemode now a valid command
  • New localized audio for Crash Course now available
  • Fixed achievement issues in Crash Course
  • Fixed dedicated servers not updating correctly to master server
  • Increased the timeout to fallback to listen server when searching for a dedicated server to 45 seconds

Left 4 Dead (360 dedicated only):

  • Item density calculation corrected for Versus games
  • Fixed weapon density in Crash Course
  • Player controlled special Infected will no longer be trapped if they spawn in rescue closets
  • Weapons and health kits in cabinets are now correctly respawned in the second Versus round
  • Fixed a deploment issue on Xbox 360 dedicated servers that resulted in collisions not being properly detected. This issue is a server only issue

September 29, 2009 (2)[edit | edit source]

  • Made the variable "mp_gamemode" available again. Note that you can also load maps directly with different game modes by specifying it in the map command. For example, "map l4d_garage01_alleys versus" will set mp_gamemode versus for you automatically and load the first map of Crash Course
  • Added "mm_dedicated_force_servers" to allow specification of a list of dedicated server addresses manually used for searching (ms_force_dedicated_server is depreciated)
  • Updated shared libraries and DLLs preventing dedicated servers listing correctly, appearing on Steam groups, and being found via sv_search_key

September 29, 2009 (1)[edit | edit source]

  • A new campaign, "Crash Course", is now available for play in Campaign, Versus and Survival modes
  • In Versus mode, all weapons, pills, health packs, molotovs, pipe bombs and other items will now be identical for the second round of a chapter
  • Matchmaking has had several improvements to make finding and joining games even faster
  • Ten all new "Crash Course" achievements have been added

September 22, 2009[edit | edit source]

The following did not appear on Steam News and is considered a 'stealth' patch.

  • HUD is updated for Infected teams in Versus. You can now view the status of the Smoker's tongue, the Boomer's vomit and the Hunter's pounce.
  • The Power Shot glitch no longer works.
  • For an unknown and possibly intentional reason, the doors marked as closets to rescue survivors from in campaign mode cannot be destroyed or opened. As an Infected, you may be able to get behind the door and destroy it. (Confirmed)
  • The likelihood of Tanks and Witches spawning has been dramatically increased, and they are now a more common sight in the first chapters of versus mode and campaign mode.
  • The Witch has a higher chance of spawning in your path, or in a narrow hallway. For example, on the stairwell/hallway of DA 1.
  • During versus mode the last survivor now has the ability to revive themselves while incapacitated after several seconds of not being damaged
  • mp_gamemode versus can no longer be used to play as Infected in Single Player Mode.

August 21, 2009[edit | edit source]


  • Fixed an exploit that allowed files to be uploaded to the server at arbitrary locations in the file system
  • Fixed a server crash caused by a client packet claiming to be an HLTV client when HLTV is disabled on the server
  • Fixed a server crash caused by spoofing a client disconnect message
  • Fixed a server crash caused by sending malformed reliable subchannel data

Left 4 Dead:

  • Novint Falcon support is now enabled by default

August 3, 2009[edit | edit source]

  • Added packet limit to help users with AT&T Speedstream routers sometimes getting disconnected.
  • Added mm_server_search_inet_ping_window convar, which can be used to further reduce packet burst when contacting Left 4 Dead servers.

July 31, 2009[edit | edit source]

  • Fixed problem with add-on installer failing to install add-ons properly on some versions of Windows.
  • Transition screen now shows campaign and map names for add-on campaigns.
  • Bug fixes and enhancements for Novint Falcon controller.

July 21, 2009[edit | edit source]

  • Lobbies and games you've recently joined and left will be ignored for two minutes. This will prevent a player from ending up in the same lobby or game when quickly searching for another.
  • Restored Find a Game Lobby/Find a Game in Progress to the Create Lobby screen available from the Lobby Browser.
  • Updated localization text.
  • Fixed an issue where VPK.EXE would not extract all files.

July 16, 2009[edit | edit source]

Left 4 Dead has been updated to include a lobby browser. The lobby browser (under Play Online) will show you a list of optimal games available for you to join. The browser pares down the thousands of lobbies and games currently being played to show you the best list of games available to you. This list includes official and add-on campaigns, including add-on campaigns you have not yet installed, making it a great way to discover them. You can filter by difficulty, official and/or add-on campaigns and by lobbies and/or games in progress. The specific changes include:

Left 4 Dead:

  • The Play on Steam Group Server screen now displays which Steam group it's searching while updating the list.
  • After calling a vote to change difficulty in game it is now correctly updated in matchmaking.

Add-on Campaigns:

  • When downloading a new version of an add-on and installing it (by double clicking the .VPK file), it will now correctly overwrite the previous version, even while Left 4 Dead is currently running.
  • Addressed a crash when two mission files with the same name are installed.
  • Steam Group Servers now will now correctly offer download links when running add-on campaigns.


  • The server will now warn if the public or private tags exceed their limits. Public tags are limited to 63 characters. Private tags used for matchmaking are now limited to 1024 characters. Note that the private tags include the name of each add-on campaign installed on the server, so an excessive number of add-on campaigns can hit this limit.


  • The VPK tool should be able to handle campaigns larger than 500MB now.
  • You can now drag and drop or pass a VPK file to the vpk.exe tool to have it extract the contents of the add-on to a folder. This mirrors the functionality of passing a folder and having it create a VPK file.
  • Detail.vbsp and lights.rad have been added to the distribution.

June 29, 2009[edit | edit source]

  • Removed the "Are you ready to play Versus?" confirmation.
  • Fixed a crash when using mouse wheel or keyboard to select Campaign chapters.
  • Fixed sv_steamgroup_exclusive servers advertising for public lobbies.
  • Restored the ability to vote for a new campaign in Versus mode.

June 25, 2009[edit | edit source]


  • Removed an infinite ammo exploit for molotovs.
  • The team swapping issue in Versus has been fixed.

Add-on Campaign Support:

  • Players download third party campaigns as single .VPK file.
  • Players can manage and select add-on maps and campaigns via game UI.
  • Added matchmaking support and download/update prompt for add-on campaigns.
  • Custom campaign support in Leader boards.
  • If not already registered, left4dead.exe registers .VPK extension to allow automatic install of add-ons.
  • Servers and the steam API have been extended to allow servers to send up a list of keys for matchmaking up to 1200 bytes in size.

Left 4 Dead Authoring Tools:

  • Fixed missing fgd error.
  • Added vpk.exe command line tool for extracting, creating, and appending .VPK files.
  • Removed info_versus (not used).
  • Added info_gamemode which fires outputs for Coop, Versus or Survival depending on what game mode the map is loaded in.
  • Updated tutorial_standards example map, repackaged as 'Dead Line' campaign example add-on.
  • Sample content now includes source files for official maps.

April 30, 2009[edit | edit source]

Survival Mode:

  • Removed an exploit from The Construction Site
  • Fixed issues with Survival Mode medals not being awarded properly in rare cases
  • Times will no longer be awarded when joining mid-round and cheats had been active during that round


  • Server will now reset correctly after all players leave a Versus game

Match Making:

  • Fixed a mismatch between lobbies and servers that will remove the "Server is full" errors when quickmatching
  • Fixed match making issue affecting Vista64 users

April 27, 2009[edit | edit source]

  • Removed a survival related command exploit
  • Achievements with multiple criteria can now be expanded to show progress
  • mp_gamemode is now included with other console variables for server logging

April 23, 2009[edit | edit source]

Survival Mode Changes:

  • Darkened the Lighthouse background movie and increased the contrast with the user interface elements
  • Chapter selection is now available when creating a Survival lobby
  • Single player coop now works correctly after playing Survival online
  • The correct game mode will be set when playing back a demo
  • Changed holdout server spew to be development only
  • Stats are no longer updated while viewing a demo
  • Correctly update the leaderboard based on the player's personal time, not the team best time
  • Show the player's best time in the scoreboard
  • Removed Survival exploits from The Terminal, Last Stand, The Crane, The Boathouse and The Warehouse
  • Fixed tanks sometimes not spawning after 15-20 minutes

April 21, 2009[edit | edit source]

The Left 4 Dead Survival Pack is now available, free of charge for the PC version and at a fee of $7 for the Xbox 360.

Survival Mode:

  • New Gameplay Mode
  • 16 maps including Last Stand
  • Leaderboards
  • 7 new achievements

Versus changes:

  • 2 new versus campaigns.
  • Fixed a case where versus team score would continue to be recalculated after the score panel was displayed.
  • Fixed an issue with recalculating the versus score health bonus for a player when they are rescued from being incapacitated.
  • Fixed being able to start a swing as an infected, then teleport to the survivors and have the claw swing hit a survivor.
  • Fixed a case where teleporting to the survivors would not reset the ability timer.
  • Fixed an exploit where you could load the chamber of a weapon with bullets by holding down the melee key.
  • Fixed a case where it was not possible to join a game while it was in a finale.
  • Fixed a rare case where listen servers would speed up the game over time.
  • Removed convars related to melee fatigue.
  • Fixed a case where infected players would get a respawn time on their initial spawn into a map.

Server changes:

  • Made ms_force_dedicated_server not require cheats.
  • Add a message when queuing a heartbeat.
  • Simplified setting of game mode.
  • Removed convars director_no_human_zombies and director_holdout_mode.
  • Added mp_gamemode [coop,versus,survival].


  • Added lobby join and leave messages

March 25, 2009[edit | edit source]

Game and client changes:

  • Introduced fatigue to the melee attack in versus mode. You will see a HUD display when your melee swing is cooling down
  • Boomer vomit will now pass through common infected
  • Addressed some surround sound detection issues
  • Fixed a rare crash when exiting Left4Dead on Windows Vista
  • Fixed a case where the complete all expert campaigns achievement was not being rewarded

Dedicated server changes:

  • Corrected an issue where Windows based dedicated were sending spurious shutdown notifications to the master causing them to delist temporarily
  • Fixed dedicated servers not resetting the versus team swap correctly--you could join a dedicated server that had a previous game that was swapped and arrive on the other team than what was selected in the lobby
  • Renamed the tags for sv_search_key to use "key:" in the server tags instead of "sv_search_key." This should help with issues of the 63 character limit of server tags
  • Fixed an occasional server crash related to voting

March 13, 2009[edit | edit source]

  • Lobby leaders can now specify in lobby settings whether to search for an official dedicated server or for the best available dedicated server. If the official dedicated search fails it will then default to the best available dedicated server automatically

March 12, 2009[edit | edit source]

  • Fixed sv_search_key appearing in server browser
  • Fixed issue where changing the sv_search_key did not update the master correctly
  • Fixed master server issue with Linux fork mode that affected availability of Valve dedicated servers
  • Tank melee attack can now hit multiple Survivors in one swing
  • Missed from the previous list changes: Fixed achievements to match stats. Past achievements not previously awarded will be shown in the game UI

March 11, 2009[edit | edit source]

Versus Mode Changes:

  • Tank melee attack can now hit multiple Survivors in one swing (false; fixed in update above)
  • Fixed Tank punch being able to hit targets behind walls
  • Fixes to 'Tank parking'. The Tank will now run back and attack the Survivors if he becomes AI due to two players expiring the frustration meter
  • Fixed a case where a Tank frustration meter could run out right as he was in his death animation and he would come back to life
  • Fixed a case where the Tank was moving too slowly while crouching and being shot
  • Tanks now have the possibility of spawning in a slightly different position for the first and second teams
  • The order that the teams play as Survivors is now determined by which team has the higher overall score. The winning team will play as Survivors first
  • The Smoker tongue can now target and grab victims through common infected
  • Increased the cone in which a Smoker can grab a target
  • The Witch no longer cuts Smoker tongues in a radius around her
  • Boomers that explode in mid-air will now hit Survivors directly below them with Bile
  • Reduced the damage that burning Hunters do to pounced victims
  • Adjusted the time at which players take over from bots to avoid 5 seconds of the bot standing idle while the player finishes connecting.
  • Fixed some cases where versus score was not being recalculated properly. It is no longer beneficial to pass pills between players at the end of the round or heal other players and then shoot them
  • Fixed a case where it was possible to spectate an AI infected and hit +use to take them over

Server Changes:

  • Added convar sv_gametype that allows server operators to limit the types of games that will start on their server. Default value is 'coop,versus'. Can be changed to just 'coop' or just 'versus' to limit to those game types

General changes:

  • Fixed a case where players would join as a dead Survivor when a living Survivor was still available
  • Fixed a case where restarting a level due to the team dying would give more than the max primary ammo on restart
  • Fixed the speaking icon showing up on the local player during level transition if voice_vox was set to 1
  • The scoreboard now shows the numeric value of a player's ping


  • Quick match will now try to match to any campaign. Removed the preference to match to games according to the player progressing through all campaigns
  • Games in a finale are now joinable via the Friends and Steam Group games list

February 05, 2009[edit | edit source]

  • Downloadable Content (available this spring): a new multiplayer game mode entitled "Survival", in addition two complete campaigns for Versus Mode (Dead Air & Death Toll).
  • A Critic's Choice Edition of the game is also heading to retail stores this spring, and will include access to all the content introduced in the L4D: Survival Pack.
  • In addition, for PC gamers and aspiring developers, the first Left 4 Dead release for the Source Software Development Kit (Source SDK) will allow the creation of custom Left 4 Dead campaigns that will be discoverable via L4D's matchmaking system. The SDK update is also due for release this spring, and is free of charge to all owners of L4D on the PC.

January 23, 2009[edit | edit source]

  • Fixed an exploit with melee where swapping weapons ignored the intended delay between swings.
  • In Versus mode, the Tank's health now reflects the damage it takes from burning.
  • Fixed an exploit related to the "joinclass" command.

January 15, 2009[edit | edit source]

  • Fixed client crash on certain video cards.

January 14, 2009[edit | edit source]


  • Fixed Survivors being able to climb surfaces marked for versus infected only.
  • Fixed a class of SurvivorBot bugs dealing with rescuing downed players.
  • Players can no longer grab ladders while flying through the air after a Tank punch.
  • Shooting near a car with an alarm that has already fired the alarm will no longer make chirping noises.
  • Improved loading time.
  • Fixed mini-gun physics exploit.
  • Fixed issue where propane tanks (and other physics objects) caused players to fall through elevators when one was thrown at a survivor.
  • Fixed rare achievement bug issues.
  • Fixed several map exploits.
  • Fixed various match making issues.
  • Fixed NAT traversal issues.

Versus Changes:

  • Added HUD elements to show status of other infected players.
  • Changed color of infected player name in chat to red.
  • Fixed exploit where players could spawn infected bots.
  • Fixed instance where a Survivor changing to the infected team would be attacked by infected bots.
  • Normalized special infected melee damage.
  • Made the following client commands cheat protected: "Kill" and "explode".
  • Fixed exploit where infected players could run away and teleport back to gain health.
  • Players can only change teams once per map.
  • Players can't change teams while other players are still loading.
  • Tank spawns at the same through the map for both teams in versus mode.
  • Made the Tank and Witch spawn directly on the escape route.
  • Increased chance of getting the Tank or Witch.
  • Fixed team swap issue.


  • Easier to pounce a Survivor who is meleeing.
  • Increased minimum damage a Hunter pounce does.


  • Fixed Smoker tongue tolerance
  • Smoker now has to be killed or the tongue destroyed for the tongue to break.
  • Survivor's cannot bash someone off the tongue until the Survivor being pulled is paralyzed or hanging.
  • Tongue attacks that fail to paralyze or hang a Survivor will use the shorter ability delay timer.
  • Fixed cases where the ability timer was not using the correct time.
  • Fixed case where you could point at a Survivor but not register a tongue hit.
  • Fixed Smoker tongue not targeting and landing properly through PZ ghosts.
  • Smoker tongue does damage every second while dragging paralyzed Survivors.


  • Bashable objects now appear with a red glow.
  • Tanks hitting a car with an alarm disables the alarm permanently.
  • Tank frustration timer is only reset by hitting Survivors with rocks or fists.
  • Reduced auto shotgun damage against Tanks.


  • Witch spawns at the same through the map for both teams.
  • Avoids spawning within a certain distance of the Tank.
  • Fixed an exploit where the Witch could be woken up and tricked into attacking Survivors.

December 5, 2008[edit | edit source]

  • Fixed Infected Players melee pushing large objects to block the survivors path.
  • Fixed +lobby exploit.
  • Fixed exploit of "hugging" the Witch from behind where she can't hit you:
  • Fixed players not being kicked from a vote by changing their name before it succeeds.
  • Disabled difficulty change votes from the console in versus mode.

December 4, 2008[edit | edit source]

  • Finding a dedicated server when starting the game from a lobby is now faster and more reliable.
  • Versus mode is now locked to Normal difficulty.
  • Difficulty on a server is now locked to the one set by the lobby reservation.
  • Fixed lagouts/spikes after level transition.
  • Fixed directory issue with spray logs in some cases.
  • Fixed video settings not saving after closing video options dialog.
  • Corrected a Boomer suicide exploit.
  • Several minor localization fixes.
  • Fixed disabling cheats incorrectly resetting data.

November 25, 2008[edit | edit source]

  • Fix for alt-tab crash in certain cases.
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