TODAY the Left 4 Dead 2 authoring tools have been released by Valve. Go ahead right now, open Steam and hit the Tools tab. There you will find Left 4 Dead 2 Authoring Tools available for download and installation.

Also... if you want to be able to play your maps and mods (this is for players too, not just modders) you must download the Left 4 Dead Add-On Support package. It's located in the same place as the Authoring Tools (in Steam) and must be downloaded and installed.

The tools are about 20Mb and the Add-on support package is about 350Mb. Hopefully this doesn't deter anyone from playing your custom content once completed.

And a few more features for you...

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.

For the best user experience and to take advantage of the new map and nav mesh formats, Left 4 Dead 1 Map Makers will want to compile Left 4 Dead 2 specific versions of their map in the new tool.

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