Installing

Most .zip files on this site are meant to be installed to your left4dead folder, which is usually C:\Program Files\Steam\steamapps\common\left 4 dead\left4dead. Everything should automatically go where it's supposed to.

This won't work for every map because not all mappers package their zip files the same way. The guaranteed way of installing a map correctly is to take the .bsp and .nav files and copy them into your maps folder.

Playing

Unfortunately, Valve has not yet enabled custom maps to show up on the campaign selection menu even if they are installed. So you have to start a game on an official map—it doesn't matter which, then manually change to the custom map by opening your console and typing: changelevel mapname (where mapname is the name of the custom map).

To open your console, make sure it's allowed in your keyboard options, then press ~ while in game.

For survival maps, you might need to type "mp_gamemode survival" into your console, although some maps do this automatically.

Notes

• Starting a game via the "map" command will work, but you'll often spawn in the wrong area.
• If you get an error saying the map is unplayable, just press OK and continue playing.