Project Zomboid Sandbox Settings: Zombies, Difficulty and Loot on Your Server
What makes your Zomboid game easier or harder (how many zombies there are, whether they run, how much loot is left, when the power goes out) isn't in the game's own menu: it's in a file on the server. It's easy to change, but it's worth knowing what applies to a game that's already started and what doesn't.
Where the file is
The game rules are in <name>_SandboxVars.lua and the server rules (password, players, PvP) in <name>.ini, where <name> is the server's name (servertest if nobody changed it); the .ini ones are explained in the server .ini guide. On NapNodes they're in the .cache/Server folder, called napnodes_SandboxVars.lua and napnodes.ini, and you open them from “Files” in the panel, with the server stopped.
On NapNodes you don't even need to open them: the panel's “Settings” has every world setting, grouped by topic (“World: zombies”, “Zombie lore”, “World: loot”…) and searchable. They save automatically and apply when you press “Restart”.
The file itself has comments explaining what each number means: read them before changing anything, because for several options 1 is the hardest setting, not the easiest. Or paste it into the Project Zomboid settings editor: every option shows up with a readable name and its value, and it gives you the file back without a single comma missing.
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The settings people change most
Zombies: how many there are. It goes from 1 (insane) to 5 (low) and 6 (none); the normal value is 4. For a small group that wants to explore without being overwhelmed, 5 usually works well.
Inside the ZombieLore block: Speed (whether they walk or run: sprinters, fast shamblers, shamblers or random), Strength and Cognition. This is the setting that changes the feel of the game the most: runners force you to play differently.
ElecShut and WaterShut: how many days until the power and water are cut off. Making them longer gives you time to set up a base; shortening them tightens the game.
Loot and food: how plentiful items and food are, and whether loot respawns. On a server with several players, scarce loot runs out fast.
Build 42 also adds settings for animals, basements and more: what changes in 42 for a server. And if the game stutters with lots of zombies or animals, the lag guide tells you what to lower first. If you're starting out as a group, which mode and settings to choose.
How to change it without breaking anything
Stop the server
Stop it from the panel before editing; otherwise it may overwrite your changes when it saves.
Take a backup
Create a backup from “Backups” in case you want to go back.
Edit one value at a time
Open the SandboxVars file in “Files” (on NapNodes, .cache/Server/napnodes_SandboxVars.lua), change one setting, save and start. If you change ten at once, you won't know which one changed the game.
Watch the console
If the server doesn't start, it's almost always a misplaced comma or brace. Undo the last change (if that's not it, why a Zomboid server won't start).
What applies to a game that's already started
Changes affect what happens from then on: areas that were already generated stay as they were, with their zombies and their loot. If you want everything to really change, you need a new world: how to reset the world without losing the old one (take a backup first).
Frequently asked questions
Where do I change the difficulty of a Project Zomboid server?
In the server's SandboxVars file (servertest_SandboxVars.lua by default), with the server stopped. On NapNodes, in the panel's “Settings”, which is searchable; the file (.cache/Server/napnodes_SandboxVars.lua) can also be opened in “Files”.
How do I stop zombies from running?
With the Speed option in the ZombieLore block: pick shamblers or fast shamblers instead of sprinters. The exact numbers are explained in the comments in the file itself.
If I change the settings, does my existing world change?
Only what gets generated or happens from that moment on. Areas that were already generated stay as they were.
Shall we set it up for you?
Project Zomboid servers from €12 a month, never oversold: your RAM is yours alone. And if you'd rather start without paying, there's a free Project Zomboid server, no card needed.
Not sure whether your server is online? Check it in a second with the Project Zomboid server status checker: players, version and password, free.
Free tool: Project Zomboid settings editor. Paste your .ini and SandboxVars.lua (or start from scratch), change their 400+ options with a search box, and download them.