ICARUS Server Configuration Guide
This is the guide we point people at when they've got their ICARUS server up and running but the defaults are biting them. If you haven't actually got the thing online yet, start with the ICARUS getting started guide and circle back here once you can connect.
A quick orientation. ICARUS is RocketWerkz's survival game (yes, the DayZ Dean Hall studio), and the dedicated server is Windows-native upstream. We run it on Windows plans for that reason, though there are community Linux Docker images floating around if you really want to go that route. The base map is Olympus and ships with the free game; Styx, Prometheus, and the newer Elysium map (Eden settlement, released March 2026) are paid DLC, and players generally need to own a DLC to join a prospect set on its map.
Where ServerSettings.ini actually lives
On a LOW.MS box, your config file is at Icarus\Saved\Config\WindowsServer\ServerSettings.ini. The fastest way to edit it is through TCAdmin at control.low.ms: open your service, go to Configuration Files, and pick ServerSettings.ini from the list. You can also use File Manager if you'd rather poke around the directory tree, but Configuration Files is the one we tell people to use because it stops the server first and restarts it cleanly.
Honestly, half the tickets we get on ICARUS are people who edited the file while the server was running and watched their changes get stomped on the next shutdown. Stop the service, edit, start. That's it.
Server name, password, slots
Here's the thing nobody tells you in the official docs: SessionName in ServerSettings.ini does not currently work. It's listed in the file. It looks legit. It does nothing. To actually set the name your server shows in the browser, you have to pass -SteamServerName=My Server on the command line. In TCAdmin that's Commandline Manager, and you can either edit the active line or add a custom one with the flag appended.
The keys that do work for identity and access are these:
[/Script/Icarus.DedicatedServerSettings]
JoinPassword=
AdminPassword=changeme
MaxPlayers=8
Leave JoinPassword blank for a public server. AdminPassword is what gates the in-game admin commands later, so set it to something real. MaxPlayers used to be hard-capped at 8 by the upstream server, but RocketWerkz removed that ceiling in Week 54, which is why our ICARUS plans go up to 20 slots. Set this to whatever your plan allows.
For everything pricing-, RAM-, and slot-related, we keep the up-to-date numbers on the ICARUS hosting page rather than baking them into a guide that goes stale.
The auto-shutdown timer (read this one)
Honestly, the auto-shutdown timers are the single thing we get more tickets about than anything else for ICARUS. Players think their server crashed. It didn't. It shut itself off because nobody joined fast enough.
ShutdownIfNotJoinedFor=300
ShutdownIfEmptyFor=300
Both default to 300 seconds (five minutes). ShutdownIfNotJoinedFor is how long the server waits after boot for the first player to connect; ShutdownIfEmptyFor is how long it stays up after the last player leaves. If you want a persistent always-on server, set both to a high value like 86400 (24 hours). Do not set them to 0. Zero means "shut down immediately," which is the opposite of what you want and is a fun way to learn that your server is mysteriously offline two seconds after starting. Some operators say -1 works as an "infinite" sentinel; we've seen it behave but it isn't documented anywhere official, so we stick with a big number.
Prospects
A prospect is ICARUS's word for a save. Prospect files have a .prospect extension and live in Saved\PlayerData\DedicatedServer\Prospects\ on the server. If you're migrating a single-player save up to your dedicated box, the local copy is under %localappdata%\Icarus\Saved\PlayerData\<your SteamID>\Prospects\. Just drop the .prospect file into the server's prospect folder via File Manager and it'll show up.
The settings that drive prospect behaviour:
ResumeProspect=True
LastProspectName=MyBase
LoadProspect=
AllowNonAdminsToLaunchProspects=True
AllowNonAdminsToDeleteProspects=False
ResumeProspect=True plus a valid LastProspectName is what you want for a persistent open-world server. The other two control whether non-admin players can spin up new prospects or delete saves from the lobby; we leave launching on but deleting off, which matches the upstream defaults and avoids the worst-case "someone wiped my base" support ticket.
If you want the server to spin up a brand new prospect on first boot, use CreateProspect. The real syntax is space-separated, and the map is implicit in the prospect type:
CreateProspect=Olympus_Outpost 3 false MyBase
That's <ProspectType> <Difficulty 1-4> <Hardcore true/false> <SaveName>. Swap Olympus_Outpost for whichever prospect template you want (open-world variants exist for each map, plus the various mission/outpost types). Once it's been created, switch to ResumeProspect=True with LastProspectName=MyBase so subsequent restarts pick up where you left off.
Open world vs mission rotation
Two common shapes for an ICARUS server. An open-world server runs one prospect forever, so you want ResumeProspect=True, AllowNonAdminsToLaunchProspects=False, and the long shutdown timers above. A mission-rotation server lets players pick what to run when they connect, so you want ResumeProspect=False and AllowNonAdminsToLaunchProspects=True. Pick a shape and stick with it; flipping back and forth is how you confuse yourself.
Admin commands (there's no real RCON)
ICARUS doesn't ship a proper RCON protocol, which surprises people coming from Rust or ARK. What you get instead is in-game admin commands gated by the AdminPassword you set above. Connect to your server, open the console, and run:
AdminLogin <password>to authenticateKickPlayer,BanPlayer,UnbanPlayer,KickAllfor moderationShutdownOnEmptyto flag the server to gracefully stop once everyone's gone
That's the lot. There is no Save command and no broadcast/server-message command, despite what some older guides claim. If you need a remote kill switch, use TCAdmin's Web Console to issue a stop, or schedule restarts through Scheduled Tasks.
Mods
No Steam Workshop here. ICARUS mods are .pak files, mostly hosted on Nexus Mods. To install them, drop the .pak into Icarus\Content\Paks\mods\ (create the mods folder if it doesn't exist) using **File Manager** or **Mod Manager** in TCAdmin, then restart. Every player who connects has to have the same .pak files installed locally, or the server will reject them.
A warning we wish we'd been given the first time. Mods break on game updates. Always grab a copy of your .prospect files before you patch, and keep a known-good backup of any mods you depend on, because the Nexus page might disappear at the exact moment you need to roll back.
Performance notes
ICARUS is a UE4 game and tends to be bound by single-thread CPU performance more than anything else. Physics, AI, weather, all of it sits on the main game thread. RAM matters too, especially for long-running open-world bases where the chunk data piles up, but you'll usually feel CPU first.
A few practical things we've picked up running these in production:
- Big bases on Prometheus and Elysium hit harder than equivalent bases on Olympus. The DLC maps have more going on environmentally.
- Tick rate degrades over very long uninterrupted uptimes. A scheduled nightly restart through Scheduled Tasks isn't strictly necessary but it's cheap insurance.
- Automatic cloud backups are on by every LOW.MS plan, and you can also pull a manual snapshot from Cloud Backup before risky changes (a game update, a mod swap, deleting an old prospect).
Ports
ICARUS defaults to UDP 17777 for game traffic and UDP 27015 for the Steam query that populates the server browser. Both UDP, both required. On LOW.MS these are set automatically when you order; if you're behind your own firewall for any reason, those are the two to open. If your server isn't appearing in the in-game browser, query port is almost always the culprit, and the troubleshooting guide walks through the fix.
If something in here doesn't match what you're seeing in your own ServerSettings.ini, open a ticket from the panel and we'll take a look at the actual file rather than guessing.