Best ICARUS Server Settings for Co-op Survival
Most of the ICARUS "best server settings" guides we read online are written as if the game exposes a console of XP and harvest dials. It doesn't. Vanilla ICARUS gives a dedicated server admin a fairly short list of things to actually configure, and the difference between a server your group loves and one that quietly dies in week three almost always comes down to about five of them. This is the list we'd hand a friend setting up an ICARUS dedicated server for their own group, written from what we see in support tickets every week.
The setting that breaks more servers than anything else
If you only change one thing in ServerSettings.ini, change this. ICARUS ships with two auto-shutdown timers, both defaulting to 300 seconds:
ShutdownIfNotJoinedFor=86400
ShutdownIfEmptyFor=86400
The defaults will stop your server five minutes after it boots if nobody has joined yet, and again five minutes after the last player logs out. On a hosted box you almost never want that. Set both to a high value like 86400 (one day) to effectively disable them. Do not set them to 0. Zero means "shut down immediately", and we get tickets every month from people who tried it and watched their server die the moment it started. The config file lives at Icarus/Saved/Config/WindowsServer/ServerSettings.ini, and the easiest way to edit it on a LOW.MS box is the Configuration Files tab in the control panel.
While you're in there, one bit of insider knowledge worth knowing: SessionName in ServerSettings.ini is currently broken and won't actually rename your server in the browser. You have to set it via the command line with -SteamServerName="My Server", which on TCAdmin lives under Commandline Manager. It's the kind of thing nobody documents and everyone hits.
Pick the right prospect type for how your group actually plays
ICARUS has three prospect categories and they suit very different groups.
Open World prospects have no timer. You drop in, you build, you can leave the planet whenever you want and come back next week with everything intact. This is what most casual co-op groups end up running, and it's what we'd default to for any group whose play sessions are irregular.
Mission prospects are the original ICARUS pitch: a timed contract with a hard extract deadline, and if you don't make it back to the dropship you lose your equipment. They're tense and they're great, but they are the wrong choice for a group that plays for two hours every other Thursday. We see Mission prospects abandoned a lot.
Outpost prospects sit in the middle: persistent like Open World, but smaller and structured around a specific facility. Good for a focused build project or a short campaign.
You can spin one up from ServerSettings.ini with the CreateProspect line, which takes the format CreateProspect=<ProspectType> <Difficulty 1-4> <Hardcore true/false> <SaveName>. So CreateProspect=Olympus_Outpost 3 false MyBase gives you a difficulty-3 non-hardcore outpost on Olympus saved as MyBase. Pair it with ResumeProspect=True and LastProspectName so the server reloads the same world after a restart.
Choosing a map
Olympus is the base game map and it's where we'd start every new group. It's gentle, it's well-tested, and every player owns it by default. Styx (from the Styx Expansion) leans harder into the survival side and is a fair next step for a group that's beaten Olympus once. Prometheus comes with the New Frontiers DLC. Elysium comes with Dangerous Horizons, which dropped in March and added Eden, the first NPC settlement in the game. The catch with any DLC map is that every player who joins needs to own that DLC themselves, which is the source of about half the "I can't connect to my friend's server" tickets we get.
Permissions: who's allowed to do what
Two settings worth a thought before you launch:
AllowNonAdminsToLaunchProspects(defaultTrue) lets any player start a new prospect. Fine for a tight friend group; we'd flip it toFalsefor anything semi-public.AllowNonAdminsToDeleteProspects(defaultFalse). Leave this one alone. There is no undo for a deleted prospect, and the one ticket category we genuinely cannot help with is "my friend deleted our 80-hour save".
Admin password and in-game commands
Set AdminPassword to something real. ICARUS doesn't have a true RCON protocol, but the admin password unlocks a small set of in-game admin commands once you run AdminLogin <password> from the chat box: KickPlayer, BanPlayer, UnbanPlayer, KickAll, and ShutdownOnEmpty. That's the toolkit. There's no Save or Broadcast command, which surprises people coming from Rust or ARK.
Player count
The Week 54 update finally removed the old 8-player cap on dedicated servers. We offer up to 20 slots on our ICARUS plans now, but honestly, most groups we host land somewhere between four and eight regulars and that's the sweet spot for co-op. Don't buy 20 slots because you can; buy what fits the people who'll actually log in.
Restarts, backups, and mods
A daily restart genuinely helps. UE4 servers tend to creep on memory over long uptimes and ICARUS is no exception, so we'd schedule one through Scheduled Tasks for whenever your group is asleep. That's the simplest performance tweak you'll ever make.
Backups should run on Cloud Backup automatically, and the rule we'd give every admin is: take a manual one before you swap prospects or install a mod. Five seconds of clicking saves an evening of "where did our base go".
For mods, ICARUS uses .pak files dropped into Icarus/Content/Paks/mods/, sourced from Nexus Mods. There's no Steam Workshop integration, so every player on the server needs the same .pak files in the same folder locally. If one player has a mod the others don't, they won't connect. We mention this because it's the second-most-common ticket subject after the auto-shutdown thing.
What we'd actually run
If we were setting up an ICARUS server for our own Thursday-night group tomorrow, it would be an Open World prospect on Olympus, eight slots, auto-shutdown timers cranked to 86400, JoinPassword set, admin password set, daily restart at 5 AM, no mods to start with. Boring, durable, and the group would still be playing it in three months. That's the version of "best settings" nobody writes a blog post about, and it's the one that holds up.
For the full key reference see the ICARUS Server Configuration Guide, and if you're standing up a server for the first time the ICARUS Getting Started Guide and Troubleshooting Guide cover the bits this article skips.