Updates to Left 4 Dead 2 have been released. The updates will be applied automatically when your Steam client is restarted. The major changes include:

Left 4 Dead 2
New mutation: Room For One.
Improved SurvivorBot’s ability to support players who stop moving to fight infected.
Improved SurvivorBot’s ability to support players in tight spaces.

Match Making Changes
Server searches for Official Dedicated servers no longer automatically fall back to Best Available. Lobby leaders will be given the option.
Lobby leaders can select "Steam Group Server" as a server option. This will allow them to select individual servers.
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