Run any custom Workshop campaign on your server, from Warcelona to I Hate Mountains. One rule: the server cannot send the campaign to players, so everyone subscribes on Steam first.
Every player who wants to join, including you, must be subscribed to the exact same Workshop campaign on Steam before connecting. A player who isn't subscribed will fail to load the map and get dropped. This is a Valve limitation (the server can't transfer custom .bsp files to clients), not something we can work around.
The flow
- On the deploy page, open the Map picker and go to the Workshop tab. Pick a featured campaign, or paste any Steam Workshop URL / ID.
- Send everyone the campaign link and have them click Subscribe on Steam. You get a one-click share link on the server card after deploying.
- Everyone restarts L4D2. Steam only downloads the add-on when the game starts. Wait for the download to finish.
- Connect. The server is already running the custom campaign.
Can't load the map?
If you get a missing map or disconnect error when joining: you connected before the add-on finished downloading. Restart L4D2, wait for the download, try again. Subscribing alone is not enough, the game must be restarted to pick it up.
Single-file campaigns only
Pick a campaign that ships as one Workshop item. Some older campaigns are split into several parts (map 1, map 2, …) or bundled as a collection; those need every part subscribed, which is fragile for a group. The campaigns we feature in the picker are all single-file, popular, and safe.