Left 4 Dead 2 SDK

Here comes the best Christmas present of all! According to the Left 4 Dead official blog, the authoring tools (SDK) for Left 4 Dead 2 have been released! In addition, the developers have also released an addon support package for players who just want to use custom content.
Players who are only looking to play custom content (including custom maps for L4D1) only need to download the support package. In Steam, open your Tools tab and look for the entry called “Left 4 Dead 2 – Add-on Support”. Click it and install it. After installing it, you don’t need to run anything. Your game client will automatically be able to play custom content thereafter.
Custom content designers should download the aforementioned file and the “Left 4 Dead 2 – Authoring Tools”. This download adds applications, utilities, and example files.
The new authoring tools are similar to Left 4 Dead’s authoring tools, but there are a number of new additions:
Gamemode Logic: Designers can now make a single map that can behave differently depending on the gamemode in which it is being played. This can dramatically reduce the file size of Campaign add-ons, as the same map can be used for Co-op, Versus, Scavenge, and Survival.
Director Logic: Maps can now alter their layout and behavior depending on how “angry” the A.I. director is. The better the Survivors are doing, the angrier the AI Director seems to get. This allows you to base variable paths and other events on the player’s skill and current conditions.
Scavenge Mode Support! All the elements map authors need to support Scavenge in their maps. This includes game props as well as a full example in the form of Deadline 2, an updated tutorial campaign.
Left 4 Dead 1 map designers are encouraged to compile L4D2-specific versions of their maps in the new tool.




