Getting tired of the included maps? Well, go to your tools and download
the Left 4 Dead 2
Add On support and go play custom campaigns. This baby will let you play custom maps from both the first and second game. Yay!
Developers will now be able to download the SDK and create your own Left 4 Dead 2
maps and characters. Don't make the A.I. Director angry. You won't like him when he's angry as you can now add in more difficult paths that the A.I. Director can lead the Survivors on should they be doing well and piss off the A.I. Director.
So if you guys aren't spending the holidays with your family, why not try and make some new content for the zombie shooter?