Dedicated server setup: hosting, ports, and multiplayer configuration

Prerequisites

The developer's dedicated-server Quickstart documents a Windows server tool. Have a Windows machine you can leave running, a way to install SteamCMD, and access to its firewall settings. If friends will join across the internet, you may also need to change router port forwarding. The players need the Abiotic Factor game; the server download itself supports anonymous SteamCMD login. A Steam login is only needed if you choose the alternative Steam Library installation route.

Decide whether the machine can remain online when the group is away. A server running on your everyday PC goes offline when you shut that PC down. Do not use a fixed RAM, player-count, or monthly-price promise from an old guide as a substitute for checking the current provider plan and your actual world load.

Linux is a separate path. The developer Quickstart labels the official server Windows-only and links a community Wine setup. That workaround forces a Windows SteamCMD download and runs the Windows executable through Wine. Installing SteamCMD on Linux and trying to run a nonexistent native AbioticFactorServer.sh is not the documented route. Use the community issue for Linux-specific commands instead of applying the Windows steps to a Linux shell unchanged.

Choosing Between Self-Hosted and Rented Server

You have two main routes for running a dedicated server. The table below outlines the tradeoffs to help you decide.

Self-hosting gives you direct control over files and launch parameters, but a home router behind carrier-grade NAT may prevent direct inbound connections. Renting avoids a home port-forwarding problem, but it does not automatically guarantee backups, migration help, or the options you need. Compare those terms rather than choosing by an unsupported price-per-slot estimate.

Self-Hosted Setup Workflow

1. Download the Windows server tool

Install SteamCMD using the link in the developer Quickstart. At its prompt, choose an install directory, log in anonymously, and install the dedicated server App ID 2857200:

force_install_dir C:\abiotic_server
login anonymous
app_update 2857200 validate
quit

Replace the example directory with one you control. Confirm that it contains the server executable at this path:

AbioticFactor\Binaries\Win64\AbioticFactorServer-Win64-Shipping.exe

This check distinguishes the server tool from a game-client download before you spend time configuring a launcher or router. You can instead obtain the Dedicated Server tool from the Steam Library's Tools section when you own the game there, as described by the same Quickstart.

2. Configure the server launch parameters

The developer's Windows Quickstart creates RunServer.bat beside the Windows shipping executable, in AbioticFactor\Binaries\Win64\. Create that file with a launch line based on the documented parameters:

AbioticFactorServer-Win64-Shipping.exe -log -newconsole -useperfthreads -MaxServerPlayers=6 -PORT=7777 -QueryPort=27015 -ServerPassword=ReplaceWithPrivateJoinPassword -AdminPassword=ReplaceWithDifferentAdminPassword -SteamServerName="My GATE Facility"

Change both example passwords before starting, and do not reuse the admin password as the join password. The private join password in this example is intentional: remove -ServerPassword= only if you deliberately want to operate a publicly joinable server. The developer's launch-parameter reference documents -PORT, -QueryPort, -MaxServerPlayers, both passwords, and -SteamServerName. It allows 1-24 players, but warns that raising the count above six is not recommended. Start with six or fewer and check actual performance before inviting more players.

The developer Quickstart configures these settings through launch parameters, not an arbitrary Game.ini block. Check the launcher after every change so the named port, player limit, and passwords agree with the setup you intend. For Steam players who do not want password-based admin access, it instead documents adding a SteamID under [Moderators] in AbioticFactor\Saved\SaveGames\Server\Admin.ini after the first server run. That file is not a substitute for setting a join password.

3. Open only the ports your setup actually uses

The developer Quickstart says that if a server does not appear in the browser, you may need to forward 7777 and 27015. The launch line above assigns 7777 to the game port and 27015 to Steam queries. Configure inbound firewall and router rules for those chosen ports, pointing to the server machine's current local IP. Community server configurations use UDP for these two game and query ports; check your hosting panel if it separates protocol rules. The developer Quickstart does not list a third default 7778 port; do not open extra ports merely because another game's server guide recommends them.

Avoid using a TCP-only web port checker as proof that a UDP game server is down. Ask a friend on a different connection to try the in-game server browser after the server process starts, and change one network condition at a time. If your ISP places the router behind carrier-grade NAT, ordinary port forwarding on that router may not provide a public path; ask about a public address or consider rented hosting.

4. Launch and keep the world available

Run RunServer.bat from the Windows server tool directory. The -log and -newconsole options from the developer's example make the launch visible. If the expected console never appears, return to the executable path and the SteamCMD download check instead of changing router rules immediately. Leave the process running for the time the group expects to play; closing the Windows server process ends the dedicated session.

Linux hosts should not run the old ./AbioticFactorServer.sh instruction. The community Linux workaround uses Windows binaries under Wine, with its own package, display and service steps. Treat that issue as community-maintained and verify it against your Linux distribution before following it. This article's copy-and-run path is the developer-documented Windows path, not a claim of native Linux support.

5. Connect and verify from another network

First confirm the server appears in the game's server browser and that a second player can join with the configured password. If it is visible but the join fails, inspect the server console, the join password and the game-port rule separately. If it is missing from the browser, check the query-port rule and the Steam server name before blaming a save file. The developer Quickstart specifically uses browser visibility as the port-forwarding check.

The source-backed test here is a real join through the game's browser from outside the home network. Do not assume a client-side console command is available or that success from the server PC verifies public routing. Keep the server console open so you can distinguish a client password error from a process or network failure while the second player connects.

Common failure points and recovery

Server runs locally but no one can connect from outside. Check the Windows firewall, the selected game port, and the router rule to the same local server IP. For the example launcher, check 7777 and 27015 rather than an extra 7778 rule. Test from a different network after confirming the server process is still running.

The server appears in the browser but connections time out. Check that the game port, not only the query port, reaches the server and that the launcher's -PORT matches the router rule. If your router does not have a public WAN address, ask the ISP about public-IP availability or choose a hosting route that does not depend on inbound home connections. Browser visibility alone does not prove that clients can complete a game session.

Admin commands do not work. Check that the launcher contains a distinct -AdminPassword parameter and restart after changing it. If you intentionally omitted that parameter, follow the developer Quickstart's Steam-only Admin.ini moderator method; do not paste AdminPassword into an unrelated Game.ini block. Keep the join and admin passwords private.

Save file loss after a crash or power outage. The developer's save-migration guide locates server worlds under AbioticFactor\Saved\SaveGames\Server\Worlds\. Back up the world folder before an update or migration, keep a separate copy, and test that you can restore it. The default world folder is Cascade; use -WorldSaveName= if you deliberately host another folder. Do not rename or replace a live save while the server is still writing to it.

The server stops when you close the terminal on Linux. That is a community Wine deployment, not the Windows executable path in this guide. Follow the community issue's service steps or your host's documented process manager and check its logs after restart. screen by itself does not turn an unsupported Linux binary into a working dedicated server.