How to Set Up an Arma 3 Dedicated Server: The Complete Guide

What an Arma 3 dedicated server is

Arma 3 is the military sandbox from Bohemia Interactive, released on Steam on 12 September 2013 and still updated: Game Update 2.22 arrived on 11 August 2026, followed by a hotfix on 26 August and a mini-update on 30 September 2026. Every multiplayer session runs on a server, and there are three ways to host one:

• From the game. The Arma 3 Launcher can start the game itself as a server: PARAMETERS, All Parameters, Host, tick Server, choose the mods and press Play. Bohemia describes this as a setup for a small, casual server, and it only runs while that PC runs it.
• The dedicated server. A separate program, Arma 3 Server, in your Steam Library under Tools: Steam downloads the Windows or the Linux version for your system, and admins can install it with SteamCMD as app 233780. According to Bohemia's dedicated server guide, the server package is free and does not need a copy of Arma 3.
• A rented server. The same dedicated server, run for you in a datacentre around the clock, with a control panel on top.

Arma 3 is played on PC through Steam. Bohemia's experimental Mac port is on version 2.22 too and can join Windows servers when both run the same version; the old Linux client port was discontinued, but the dedicated server still runs natively on Linux.

Host it yourself or rent a server: an honest comparison

Running your own dedicated server costs nothing but hardware, power and your connection, and it is a good way to learn how Arma 3 servers work. Bohemia's documentation covers the steps:

1. Check the machine. Bohemia's wiki lists a 2.4 GHz dual-core CPU, 2 GB of RAM and 32 GB of disk as the minimum, and a 3.5 GHz quad-core, 4 GB of RAM and a 32 GB SSD as recommended, on Windows Server 2008 or later or a modern Linux distribution. Mods, players and AI push those numbers up fast (performance).
2. Install it with SteamCMD: app_update 233780 validate. SteamCMD needs a Steam login and caches it, so Bohemia suggests a separate Steam account with no purchases for the server.
3. Start it. Write a server.cfg (the settings that matter) and start arma3server_x64.exe with -config=server.cfg, -port=2302 and -profiles= for the profile folder. On Linux: ./arma3server_x64 -name=server -config=server.cfg; Bohemia notes that -profiles does not work there.
4. Open the ports: UDP 2302 to 2306 (game and voice, Steam query, Steam master, a reserved voice port and BattlEye). A second server on the same machine needs its own set, and Bohemia suggests a gap of 100 (2402 to 2406). The server needs a real IPv4 connection: IPv6 and DS-Lite tunnels are not supported.
5. Keep it running. Update it with SteamCMD after every patch and leave the machine on whenever your unit plays.

Our view after hosting game servers since 2008: a squad with a spare PC and a good upload can start at home. Rent one when the server must run while you are offline, when you run a modded unit server or a public server, or when a full op would swamp your home upload. See our Arma 3 server hosting plans for current prices and locations.

Setting up your Arma 3 server in the GTX game panel

A GTX Arma 3 server is installed when you order it and starts as a clean vanilla server for your own mods and missions. Open it in the game panel and the Connection & Controls box shows CONNECTION INFO (the address and game port players join), QUERY INFO, RCON INFO and SFTP INFO. Your game port is not always 2302: use the one shown there. Then:

1. Press STOP. Change files only while the server is stopped.
2. Press Configuration Files: server.cfg, basic.cfg, Start.bat (the startup line, including -mod=), Workshop.mods, the BattlEye configs and the difficulty profile open in your browser.
3. Add mods with the Steam Workshop button: browse the Arma 3 Workshop inside the panel and press Install. Workshop.mods keeps your Workshop and server-only mods in one list (mods and keys). Creator DLC, phpMyAdmin and Server Messages come from the Mod Manager.
4. Upload missions to MPMissions with the File Manager or over SFTP.
5. Press START and open the Web Console: if the server does not come up, the last lines name the file, mod or setting that stopped it.
6. Start Arma 3 with the same mods, open Multiplayer and find your server by its name, or use Direct Connect with the address from CONNECTION INFO.

The other buttons cover daily running: Log Viewer and Activity and Stats (logs and live graphs of players, CPU and memory), Steam Update (game updates), Scheduled Tasks (restarts and backups), Backup Manager, Server Details (passwords and ports in one place) and Switch Game. Moving an existing server to us? Upload your server.cfg, missions, mod folders and keys with the File Manager or over SFTP, restart, and the server carries on where it left off.

server.cfg and basic.cfg: the settings that matter

Arma 3 reads its server settings from the file given with -config (the name server.cfg is only a habit) and its network tuning from the file given with -cfg, usually basic.cfg. On a GTX server both are under Configuration Files. The settings most owners change first, with the defaults from Bohemia's server config reference:

• hostname = "My Unit Server"; the name in the server browser.
• password = ""; set one for a private server. passwordAdmin is the password for #login (admins).
• maxPlayers = 40; the default on a dedicated server is 64. The real limit is the lower of this and the mission's playable slots, and Headless Clients count as players.
• motd[] = { "Welcome", "Teamspeak and rules on our Discord" }; welcome lines, shown one by one every motdInterval seconds.
• BattlEye = 1; on by default. Every player then needs BattlEye running to join.
• verifySignatures = 2; the default: every addon is checked against its signature and your keys (keys). 0 switches the check off.
• kickDuplicate = 1; kicks a second player who joins with an ID that is already playing.
• persistent = 1; keeps a mission running after the last player leaves, for missions with base or instant respawn.
• voteThreshold = 0.33; the share of votes needed (default 0.5), and voteMissionPlayers, how many players must be connected before mission voting starts.
• disableVoN = 0; keeps in-game voice on; vonCodec = 1 uses the OPUS codec.
• forcedDifficulty = "regular"; Recruit, Regular, Veteran or Custom. A difficulty set in the mission rotation wins over it.
• class Missions the mission rotation (missions), and headlessClients[] / localClient[] for a Headless Client (Headless Client).

basic.cfg holds the network tuning: MaxMsgSend (default 128 messages per frame), MinBandwidth (default 131072 bps), MaxBandwidth, MaxSizeGuaranteed (512) and MaxSizeNonguaranteed (256). Bohemia warns that too optimistic bandwidth values can increase lag and CPU load, so change one value at a time and test it on a full server. The difficulty profile (server.Arma3Profile) holds the Custom difficulty options, such as third-person view, crosshair and name tags; they only apply when the server runs the Custom difficulty.

Missions, mission rotation and difficulty

An Arma 3 server always runs a mission: a .pbo file named mission.terrain, for example MyOp.Altis.pbo, that sets the map, the factions and the rules. Upload missions to the server's MPMissions folder (on GTX with the File Manager or over SFTP). Then pick what runs:

• In game. Log in as admin and type #missions to choose from the list, or #mission MyOp.Altis Veteran to start one directly with a difficulty.
• Automatically. Add a rotation to server.cfg: class Missions { class Op1 { template = "MyOp.Altis"; difficulty = "Regular"; }; };. template is the mission name plus the terrain, without .pbo, and both template and difficulty are required. Write the keyword class in lower case, or the file will not parse.
• Mission settings. An optional class Params inside each entry changes the mission's own parameters, such as respawn delay or tickets. randomMissionOrder = true; shuffles the rotation.
• Running with nobody online. With persistent = 1, the -autoInit startup parameter starts the mission without waiting for the first player; it is skipped when persistent is not set.

Official and Creator DLC missions use their template names too: S.O.G. Prairie Fire's first co-op mission, for example, is vn_coop_01.cam_lao_nam. Zeus, the free game master mode, lets a player place units, objectives and events live during a Zeus mission. To change a mission's files, unpack the .pbo with PBO Manager, edit it, repack it and upload it under the same name with the server stopped (editing a mission with PBO Manager).

Mods on an Arma 3 server: -mod, -serverMod and keys

Mods are where Arma 3 lives: Bohemia counts over 160,000 user-generated items on the Steam Workshop. A server loads them in two ways, according to Bohemia's startup parameters:

• -mod=@CBA_A3;@ace loads mod folders that players need as well, separated by semicolons.
• -serverMod= loads server-side mods that are not broadcast to players.
• On Linux, put a backslash before each semicolon inside quotes, keep -mod paths relative to the Arma 3 folder, and watch file names: Bohemia notes that some mods, such as CUP Terrains, fail when their files contain capital letters.

Keys and signatures. A signed mod ships a .bikey file. Copy it into the server's keys folder: with verifySignatures = 2 the server checks every addon against those keys, so players with unknown or unsigned addons cannot join. That is how a server keeps its mod list clean.

1. On GTX, press STOP, then Steam Workshop: browse the Arma 3 Workshop in the panel and press Install on each mod. No mod IDs to copy.
2. Check Workshop.mods in Configuration Files: it lists your Workshop mods and any server-only mods in one place.
3. Copy each mod's .bikey into the keys folder with the File Manager.
4. Press START and read the Web Console until the server is up.
5. Share a Steam Workshop collection with your players: everyone needs the same mods as the server, and after a mod update the server and the players update together.

Most unit setups build on CBA_A3 (the base most big mods need), ACE3, a radio mod such as TFAR or ACRE2, and CUP's terrains, weapons and vehicles. Add mods a few at a time and test after each batch: when the server stops starting, you know which mod to look at. Running a complete mod framework instead, such as Exile or Altis Life? See mod servers.

DLC, Creator DLC and who can join

Arma 3's DLC does not split a server's players. Under Bohemia's DLC restrictions, players who do not own a DLC still play alongside owners, with limits:

• They cannot pick up premium DLC weapons and gear, or take the driver, gunner or commander seat of a premium vehicle. Passenger seats, including firing-from-vehicle seats, are open to everyone.
• They cannot access a DLC terrain at all, so a mission on Tanoa (Apex) or Livonia (Contact) needs every player to own that DLC. Altis, Stratis and the free Malden keep everyone in.
• A DLC-restricted mission cannot be started without the DLC.

Creator DLC are third-party expansions published by Bohemia, and their data is not part of a regular install. Bohemia's Creator DLC page links free "compatibility data for non-owners" on the Steam Workshop for each pack, so non-owners can join a server that runs one, while the Creator DLC terrains stay owner-only. Since the 2.22 hotfix the Launcher offers that compatibility data when a non-owner tries to join. Server admins do not need to own a Creator DLC to host it.

On GTX, stop the server, install Arma 3 Creator DLC from the Mod Manager, add the DLC's code to the -mod= field in Workshop.mods or Start.bat, and set a DLC mission as the template (the Creator DLC guide has the mission names). The codes, each ending in a semicolon:

• Global Mobilization: gm; and S.O.G. Prairie Fire: vn;
• CSLA Iron Curtain: csla; and Western Sahara: ws;
• Spearhead 1944: spe;, Reaction Forces: rf; and Expeditionary Forces: ef;

Admins, server commands and BattlEye

Arma 3 has two kinds of in-game admin. A logged-in admin types #login and the passwordAdmin password in chat; players whose IDs are listed in admins[] = { "<UID>" }; can type #login alone. A voted-in admin is chosen by the players and has fewer commands: Bohemia's example is that a voted admin can kick but only a logged-in admin can ban. Without BattlEye RCon, only one admin is logged in at a time: a second admin waits until the first types #logout, and a logged-in admin takes over from a voted one.

The commands you will use most, from Bohemia's server command list (always with the # in front):

• #missions opens the mission list; #restart restarts the mission; #reassign starts over with role selection.
• #kick name, #exec ban "name" and #exec unban "UID"; in Arma 3, #exec needs the name, UID or player number in quotes.
• #lock and #unlock stop or allow new players joining.
• #restartserver, #restartserveraftermission and #shutdown; #init reloads the server config.
• #monitor 1 shows the server's performance every second; #monitor 0 stops it.

BattlEye is Arma 3's built-in anti-cheat (BattlEye = 1). Its RCon lets you run admin commands without being in the game: Bohemia's BattlEye page sets RConPassword (and optionally RConPort, which must stay outside the game's ports 2302 to 2306) in BEServer_x64.cfg in the server's BattlEye folder, and then you connect with an RCon tool. BattlEye's GUID and IP bans are kept in bans.txt in the same folder. On GTX, the BattlEye configs are under Configuration Files, the RCon address is the RCON INFO line, and the Web Console has an RCon Password field to run commands from your browser.

The Headless Client: taking AI off the server

Every AI unit on the map is simulated by the server, which is what makes big co-op ops heavy. A Headless Client is an extra Arma 3 instance with no player that takes AI calculations off the server. It is built into the game and the dedicated server, on Windows and Linux. How it works, from Bohemia's Headless Client page:

• The server only accepts Headless Clients whose IP is listed in headlessClients[] (several are allowed); list the IP in localClient[] as well to give it unlimited bandwidth.
• The Headless Client starts with -client -connect=<server IP> -password=<server password> and takes a free Headless Client slot.
• The mission must be built for it: a named, playable Headless Client unit (Game Logic, Virtual Entities) and scripts that spawn the AI on it. Without that it connects and does nothing.
• It counts as a player for maxPlayers, it is excluded from signature checks, and -serverMod does not work with -client.

We sell the Headless Client as its own server, Arma 3 Headless Client server hosting. To link it: stop the main server and add the Headless Client's IP to localClient[] and headlessClients[] in server.cfg; stop the Headless Client and put the main server's IP and game port in the -connect= field of its Start.bat (and the password in -password=); then start the main server first and the Headless Client second (full Headless Client setup).

Server FPS, RAM and player count

An Arma 3 server's work is simulation: AI, scripts, vehicles and the players themselves. What Bohemia documents about server performance:

• Server FPS. A dedicated server or Headless Client is capped at 50 FPS by default; -limitFPS changes it (5 to 1000). Since update 2.20 an empty server limits itself to 30 FPS, and 2.22 added idleFPSLimit to server.cfg to set that empty-server cap yourself.
• Multithreading. Update 2.20 moved Arma 3 to the job system of Bohemia's Enfusion engine and multithreaded parts of AI simulation, AI visibility and target scanning, PhysX and join-in-progress processing. Bohemia says the gain varies, and script-heavy mods gain the least.
• Old tweaks. Bohemia says -exThreads should not be used any more, and advises using -maxMem only if you have memory problems. Since 2.20 the 32-bit build is deprecated: run arma3server_x64.
• Missions. -loadMissionToMemory keeps the mission pre-processed in memory for the next players who join, which saves server CPU.
• Watching it. #monitor 1 shows the server's performance in game; on GTX, Activity and Stats graphs players, CPU and memory over the day.

Players: pick a slot for every player online at the same time, plus one for each Headless Client. The real limit is the lowest of your slots, maxPlayers and the mission's playable slots. Our Arma 3 plans, from the plans page:

As a rule of thumb from our own servers: the 5 GB included with every server suits vanilla missions for a squad, while big mod sets such as ACE3, CUP or RHS, large terrains, persistent campaigns and lots of AI need more. We recommend 8 GB for a modded 40 player unit and 12 GB for 80 players or heavy mod lists. Low server FPS with lots of AI is processor work, not memory: cut the AI count or move it to a Headless Client, and add RAM when the memory graph fills up. Slots, RAM and CPU priority can be changed at any time from the Client Area.

Updates, restarts and backups

Bohemia updates the dedicated server together with the game: each update note lists the Windows and Linux dedicated servers among the changes. Because players can only join a server on their own version, update the server on patch day. A safe routine on GTX:

1. Take a backup: STOP, Backup Server, wait for it to finish.
2. Press Steam Update to bring the server to the new version.
3. Update your Workshop mods, so the server and your players run the same versions.
4. Press START and read the Web Console until the server is up.
5. Join it yourself before you tell your unit it is back.

Restarts. A Scheduled Restart task in Scheduled Tasks restarts the server on a timer, for example every 6 hours, and the automatic backups run alongside restarts. Arma 3 can also restart itself: missionsToServerRestart = 8; restarts the server process after eight mission ends, and #restartserveraftermission does it once from chat.

Backups. Keep copies of server.cfg, basic.cfg, the profile, MPMissions and keys, and for Exile, Altis Life or Epoch the database as well. On GTX the Backup Manager holds dated backups you can download, Restore Server puts the server back to one, and a Scheduled Backup task makes them for you. A reinstall wipes every server file but keeps your backups and MySQL databases, so download a backup first.

Exile, Altis Life, Epoch and other mod servers

Some Arma 3 game modes are complete frameworks with their own mission file, server-side mods and a database. We run them as their own server types, each with its own page: Arma 3 Exile, Altis Life, Arma 3 Epoch, A3Wasteland and Desolation Redux. What owners ask us most:

• Exile maps. Chernarus, Chernarus Summer, Winter, Isles and Redux need the CUP terrain mods; Esseker needs CUP Terrains Core and Esseker. Download them with the Workshop Mod Downloader, load them on the -mod= line of Start.bat, install the matching Map Pack and pick the Exile template in config.cfg. Install the map first and test it before you add other mods.
• Exile traders. Items go in the mission's config.cpp twice: with a quality and price in class CfgExileArsenal, and in a category of class CfgTraderCategories.
• Altis Life whitelists. Police, medic and admin levels are columns of the players table in the server's MySQL database (in the standard framework coplevel 0 to 7, mediclevel and adminlevel 0 to 5). Edit them with Navicat or phpMyAdmin; a player appears only after joining once.
• Epoch database. Epoch keeps its data in Redis, saved as appendonly.aof and dump.rdb in the DB folder. Stop the server, edit a copy on your PC and upload both files back.

Every framework's mission is a .pbo in mpmissions: keep an untouched copy before you edit it. All the step-by-step guides are listed under Exile servers and Altis Life and Epoch above.

Troubleshooting an Arma 3 server