In August 2010, Chet Faliszek announced Valve would begin to rotate biweekly custom-made campaigns on the official servers of Left 4 Dead 2:
Every two weeks we are going to feature a new community campaign on our servers. We will feature one campaign at a time to make it is easier to find games. We’ll be keeping it featured for two weeks so people can familiarize themselves with the maps for competitive play.1
Though we wholeheartedly agreed with Valve on their choice to start their campaign off with 2 Evil Eyes, their subsequent picks have not been as bold as we had hoped, as the team has since gone on to pick Detour Ahead, City 17, Haunted Forest, Dead Before Dawn, One 4 Nine and I Hate Mountains. Now that the slow trickle of maps seems to have dried up – sans Cold Stream, of course, which is still a river running wild – we wanted to introduce to old and new players alike a list of five great Left 4 Dead 1 and 2 custom campaigns – that is, the best maps Valve is yet to highlight.
We applied a loose criteria to this list of Left 4 Dead 1 and 2 maps. First and foremost, each level was to be available for both games. Second, we expected proper playability on the “expert” difficulty setting. Third, all these levels enjoy a degree of popularity in the community, so as to make finding servers and players easier. Fourth, we did somewhat consider artistic merits like overall look and feel, setpieces, setting and brushwork.
Fifth, we also sought out campaigns that would adhere to the gameplay standards and Left 4 Dead fiction as defined in practice by Valve. This meant no nasty surprises, traps, or major changes to campaign flow. The reason all the campaigns below have been tested and completed on the “expert” difficulty level is because we found that this particular setting best reveals the extent of balancing (or lack thereof) in terms of campaign length, pacing and structure.