How to host an Icarus server (2026)

Short answer. You can host an Icarus server yourself for free: install the Icarus Dedicated Server (Steam app 2089300) with SteamCMD using an anonymous login, set your passwords in ServerSettings.ini, start IcarusServer.exe with -Log and open the game port (17777 by default) and the query port (27015 by default). Or rent an Icarus server and skip the networking.

Players join from the in-game Join Session screen by switching the browser to dedicated servers and picking your server. The developer's own setup guide covers Windows, and so does the rest of Option 1.

Checked on 5 November 2026 against Icarus Week 256 (30 October 2026), the newest weekly update RocketWerkz had posted on Steam.

This guide uses two sources: the dedicated server wiki that the developer, RocketWerkz, publishes on GitHub, and what we run on every Icarus server we host. To skip to the rental route, go to Option 2.

What you need

• The server software: "Icarus Dedicated Server", Steam app 2089300. RocketWerkz notes that installing it through SteamCMD does not need an Icarus licence, so an anonymous login is enough.
• A machine that stays on: a spare PC, a home server or a cloud virtual machine. The developer's setup guide is written for Windows (IcarusServer.exe). We run the same Windows server under Wine on Linux, but RocketWerkz documents no Linux route, so this guide does not either.
• Hardware: RocketWerkz does not publish server requirements on the wiki. Treat any figure you read elsewhere as an estimate. Our How much RAM does an Icarus server need? covers what to expect.
• A player cap: MaxPlayers in ServerSettings.ini accepts 1 to 8 according to the wiki.
• Network: the game port, 17777 by default, and the query port, 27015 by default, forwarded to the machine. Both can be changed with -PORT= and -QueryPort=.
• The game: every player needs their own copy of Icarus.

Option 1: host it yourself

These steps follow the developer's wiki pages "Server Setup", "Server Config & Launch Parameters" and "Updating Dedicated Server and Running your Server".

Install the server

1. Install SteamCMD from Valve's page and run it.
2. Choose the install folder and download the server at the SteamCMD prompt:

   force_install_dir C:\IcarusServer
   login anonymous
   app_update 2089300 validate
   quit

3. Check the download worked. We ran into SteamCMD reporting success while leaving no game files, so our install script checks that Steam's appmanifest_*.acf file exists inside steamapps and tries again if it does not. Do the same by eye: if the folder has no steamapps manifest, run step 2 again.

Write the settings

1. Get the template. The wiki says the settings file is only generated once the server has started its first prospect or lobby, and offers a ready copy in the IcarusDedicatedServer repository on GitHub (ServerSettings.ini).
2. Put it in the right folder: [ServerInstallDirectory]\Icarus\Saved\Config\WindowsServer\ServerSettings.ini. The folder matters: the wiki names only this one, and on our own servers a copy one folder up in Saved\Config was never read. If you move the Saved folder with a launch argument such as -UserDir=, the wiki says to put the file in [YourSavedFolder]\Config\WindowsServer\ instead.
3. Set the keys you need. The section is [/Script/Icarus.DedicatedServerSettings]:

   JoinPassword=pick-a-join-password
   MaxPlayers=8
   AdminPassword=pick-an-admin-password
   ResumeProspect=True

   JoinPassword is what players type to get in; empty means no password. AdminPassword is what a player types after /AdminLogin to become admin. The wiki warns that if you leave it empty, typing /AdminLogin alone gives any player admin rights. SessionName in this file does nothing according to the wiki: the name comes from the launch argument in the next section.
4. Edit the file while the server is stopped.

Open the ports, start it and join

1. Forward the ports. Forward the game port and the query port (17777 and 27015 if you keep the defaults) on your router and allow them in your firewall. The wiki does not name the protocol, so test from outside your network after you start the server.
2. Start the server with launch arguments. The wiki recommends a shortcut to IcarusServer.exe with -Log, which opens a log window (without it nothing is visible while the server runs):

   IcarusServer.exe -Log -SteamServerName="My Icarus Server" -PORT=17777 -QueryPort=27015

   -SteamServerName sets the name players search for and is limited to 64 characters.
3. Join it. In Icarus, pick your character, choose Join Session in the HAB menu, use the toggle at the top right to switch the browser to dedicated servers, then select your server. If the server is not running a prospect yet, you land in the Server Lobby instead, where you can choose a prospect or an outpost.
4. Become admin. Type /AdminLogin yourpassword in the in-game chat. A / or \ starts a command. The other admin commands include /KickPlayer, /BanPlayer, /UnbanPlayer and /ReturnToLobby.
5. Update by closing the server and running the SteamCMD download again (app_update 2089300 validate), then start the server. The wiki's update script does exactly that with taskkill and a small SteamCMD script file.

Start a prospect on its own

An Icarus server hosts prospects. With ResumeProspect=True it resumes the last prospect when it starts. To start one without the lobby, the wiki gives a CreateProspect setting, for example -CreateProspect="Tier1_Forest_Recon_0 3 false TestProspect01": a prospect type, a difficulty from 1 (easy) to 4 (extreme), whether it is hardcore, and a save name. LoadProspect=[name] loads a saved one from Saved/PlayerData/DedicatedServer/Prospects/. If your world came from a solo game, see How to upload your own Icarus world.

Option 2: host it on PlayNHost

Renting removes the install, the port forwarding and the update routine. You still choose a name, passwords and your prospect.

1. Pick a plan. Open the Icarus server hosting page and compare the plans: BIHU (4 players) and BULWARK (8 players) at the time of writing. Press Create Server (Customize Plan on BULWARK) and finish the order. Prices change, so check them on that page.
2. Wait for the install. The server appears in the panel. Its Console shows Game Engine Initialized when the engine is up.
3. Set the name and passwords. On the Settings tab set the Server Name (up to 32 characters) and, if you want a private server, a Join Password for your players, then restart. Each new server already has its own random Admin Password; change it there if you want one you can remember. Both passwords take 4 to 32 letters, numbers and the symbols . _ - only.
4. Invite your players. Give them your Server Name and, if you set one, the Join Password. They switch the Join Session browser to dedicated servers and search for that name. See How to join your Icarus server.
5. Make yourself admin. Join, then type /AdminLogin followed by your admin password in the chat. See How to become admin on your Icarus server and use admin commands.

What the panel does for you:

• It writes your player limit, Join Password and Admin Password into ServerSettings.ini at every start, in the folder the game reads, so you change them in the panel and not in the file. It also sets ResumeProspect to True, and sets AllowNonAdminsToLaunchProspects to True and AllowNonAdminsToDeleteProspects to False, the wiki's defaults.
• It sets ShutdownIfNotJoinedFor and ShutdownIfEmptyFor to 0 (the wiki's default is 300 seconds). The wiki says 0 sends the server back to the Server Lobby as soon as possible when nobody has joined or the last player leaves. So the first player in usually lands in the lobby and resumes the last prospect or loads another from there, which any player can do because non-admins are allowed to launch prospects.
• It starts the server with the game and query ports it assigns, so there is nothing to forward. See Icarus ports and firewall explained.
• It prepares the folders Icarus mods are read from (Icarus/Content/Paks/mods and Icarus/Mods), since Icarus has no Steam Workshop. See How to add mods to your Icarus server.
• Auto Update is a setting on your server and is on by default: while it is on, the server downloads any new Icarus server build from Steam each time it starts. See How to update your Icarus server.

Self-hosting or renting: an honest comparison

• Cost: the server software is free. Self-hosting costs power, hardware and bandwidth, or a cloud machine. Renting is a monthly fee set by the plan.
• Availability: a home server is only up while your PC, power and internet are. A rented server runs on the host's hardware.
• Exposure: at home, players connect to your public IP address and you look after the firewall and router. A rented server keeps your home IP out of it.
• Setup: self-hosting needs a Windows machine (or your own Wine setup), port forwarding, the settings file in the right folder and your own updates. Renting needs a server name and, if you want one, a join password.
• Control: self-hosting gives you every file and launch argument. On our servers you change settings in the panel and still have the Files tab.
• Player cap: the game's own setting tops out at 8 players, so a rented plan does not offer a bigger server than a self-hosted one could.

Ready to skip the setup? See the Icarus server plans. Already have a server? Start with How to set up your Icarus server: key settings.