Set up a dedicated Project Zomboid server (Build 42)
Now that Build 42 multiplayer has reached the stable branch, a dedicated server is the simplest way to keep a world alive between sessions: it runs without leaving your PC on, and you only pay for the hours it actually runs.
1. Create the server
Pick Project Zomboid, the amount of RAM and the sandbox preset. The server starts on its own, and you get a stable connection address to share with your group.
2. The sandbox preset
Apocalypse is the default — the hardest one, the classic campaign settings. The others available: Survivor, Survival, Builder, FirstWeek, SixMonthsLater and Beginner.
⚠️ The preset is chosen at creation and cannot be changed afterwards: it defines the world itself. To try another one, create a second server.
3. Join the game
In game: Play → Join → Add server, then paste the address and password shown in your console.
There are no ports to forward: the game ports (16261 and 16262 over UDP) and the Steam ports (8766 and 8767) are already handled. Older tutorials asking you to open a whole range, one port per player, predate 41.65 — that requirement is long gone.
4. Mods, without the usual trap
A Project Zomboid server needs two different lists, and mixing them up is the number one reason a server refuses to start:
WorkshopItems=— the Steam IDs of the mods (the numbers you see in the Workshop URL);Mods=— the internal IDs, written inside each mod'smod.infofile, which have nothing to do with the ones above.
Here, you only fill in the first list. On the first start the server downloads the mods, we read the downloaded mod.info files, derive the internal IDs and restart the server with the right configuration. If nothing could be downloaded, we refuse to start rather than quietly booting a vanilla world — that is the kind of surprise you discover three evenings later.
⚠️ Build 41 mods do not work on Build 42: the modding system was rebuilt and every mod has to be ported by its author.
5. How much RAM?
- A group getting started, few or no mods: 8 GB.
- Large group, or a lot of mods: 16 GB.
The part most guides leave out: memory use grows as you explore. A three-week-old world with a widely explored map and built-up bases is significantly heavier than a fresh one. You can move up a tier whenever you need to, without losing your game.
6. Time passes while you're away
On a server left running around the clock, the world keeps ageing while nobody plays: power and water eventually shut off (two in-game weeks by default), crops wither, generators run dry, food spoils.
Two protections are on by default: pause when nobody is connected (time stops while the server is empty), and above all the fact that a stopped server ages nothing at all. You come back to the world exactly where you left it, even three weeks later.
7. Shut down when you're done
Server off = €0. Auto-shutdown kicks in on its own when nobody is connected, the world is saved on shutdown and restored on the next start.