Just start a game like you would with one of the official Valve campaigns and people will be able to join your game if they have the same maps as you do. There will be the option to download whatever maps you're playing for users who don't already have the maps. OnyxJuvie. • 3 yr. ago. I usually play with a script addon limiting the amount of commons and I reskin them to look more like sh monsters. There is no L4Ds infected in gmod since they were different version of source engine and require some coding to implement in game. Mounting L4Ds just give you the (buggy) maps and models. Nothing else. The cable car ride is my favorite part. Deathrow is a very dark map but still playable. I've tried the silent hill campaign but as I never tried any of their games, I don't really know where to look for that damn key even with the tips on. Edit: Forgot to mention Back to School and Dam It remastered. It crashes when I get pounced, get ridden on, on the first two maps of both custom and main campaigns, and being swarmed by a horde. I tried validating the files, sometimes works, mostly does nothing to stop it/ Uninstalling it, nothing Clean reinstall, nothing Disabling as much addons as possible, nothing Nothing worked. How to create or host a Left 4 Dead 2 local (LAN) game: 1. Open the Developer Console by pressing ` on your keyboard. (It is the key below Esc.) 2. Type sv_lan 1 then press Enter. 3. Type sv_allow_lobby_connect_only 0 then press Enter. 4. In the console, type map then press Space. 5. Right after you press Space all the playable maps will be Today me and my friend were trying to play left 4 dead 2 custom maps (death row to be specific) we've played 6 custom campaigns and they've all worked fine, then today all of a sudden, everything stopped working for him and he couldn't even join my game, we can't even play previous maps we've played through already outside of vanilla left 4 dead. Mods, Community servers and Custom maps.There is plenty things to do even after you beat all the campaigns. I got 300+ hours on this game and what keeps me coming back is playing a community server called alliance coop and it has 25 players on one map and its very fun. Left 4 Dead Custom Maps Online. Tutorial on how to play custom maps online A Left 4 Dead (L4D) Tutorial in the Other/Misc category, submitted by RandiKatt^. m9Lvg3x.