Running Milsim Operations with Arma Reforger Game Master Mode

Game Master is the best part of Arma Reforger, honestly. Nothing else in the game lets you run a scenario as it unfolds, tuning enemy pressure and pacing to what your players are actually doing. If you want to run proper milsim ops for a unit or a group of friends, a rented dedicated server is the right place to do it: you control the scenario, the mods, the password, and who gets to touch the Game Master interface.

This is a practical walkthrough for getting a GM server up, authenticating yourself as Game Master in-game, and running an op without falling into the usual traps.

What Game Master actually is

Game Master is Arma Reforger's real-time scenario editor, the direct descendant of Arma 3's Zeus. A GM player sees the battlefield from above, places units and objects, assigns waypoints, possesses AI, changes weather and time, and triggers events while everyone else plays on the ground. It ships in the base game on two official GM scenarios (Everon and Arland), and it's enabled by setting the right scenarioId in your server config.

Setting up a Game Master server

You need a dedicated server running one of the Game Master scenarios. On LOW.MS you can set this from the Configuration Files section of your TCAdmin panel at control.low.ms. If you haven't set the server up yet, run through the getting started guide first and come back here.

The two verified official GM scenario IDs are:

• Game Master Everon: {59AD59368755F41A}Missions/21_GM_Eden.conf – the classic ~51 km2 Everon, rebuilt in Enfusion. Forests, towns, coastline, open fields. This is the one most GM groups default to.
• Game Master Arland: {2BBBE828037C6F4B}Missions/22_GM_Arland.conf – smaller and different in character, useful when you want a change of pace.

A minimal GM-ready game block in your config.json looks like this:

{
  "game": {
    "name": "LOW.MS | Milsim Ops",
    "password": "ops-night-password",
    "passwordAdmin": "something-long-and-not-changeme",
    "scenarioId": "{59AD59368755F41A}Missions/21_GM_Eden.conf",
    "maxPlayers": 32,
    "visible": false,
    "crossPlatform": true,
    "gameProperties": {
      "disableThirdPerson": true,
      "battlEye": true,
      "VONCanTransmitCrossFaction": false
    }
  }
}

A few opinionated notes. Most milsim groups set disableThirdPerson to true, keep the server password-protected so only unit members connect, and turn visible off to keep the server out of the public browser. passwordAdmin is the value you'll use in a minute to authenticate as GM, so treat it like a real secret and do not leave it as changeme.

For the full set of config keys and defaults, the server configuration guide is the reference.

On resources: GM operations with a lot of AI are heavier than vanilla Conflict because you're spawning and controlling units dynamically. LOW.MS ships Reforger servers with generous RAM included and larger tiers available on the order page, so pick the tier that matches your expected player and AI count on the Arma Reforger pricing page rather than guessing GB numbers here.

Authenticating as Game Master in-game

There is no "first player to connect automatically becomes GM" shortcut. The real flow, in order:

1. Set game.passwordAdmin in your config.json and restart the server.
2. Join the server as a normal player.
3. Open chat and type #login <yourAdminPassword>. You should get a confirmation that you're now authenticated as admin.
4. On a GM scenario, pick the Game Master role from the spawn/role selection menu.

Once you're in the GM role, the Mode and Toolbar interfaces are opened via the keybinds shown in the GM HUD. I'm deliberately not hard-coding the key names here because Bohemia has tweaked the defaults between patches and the in-game HUD is always the source of truth.

If #login doesn't work, it's almost always one of three things: you forgot to save the config, the server didn't actually restart, or you're typing the password into global chat instead of the command line (in Reforger, #login is recognised in the normal chat input). Our troubleshooting guide has more on admin auth issues.

Running an op

A GM is a director, not a player. The job is to keep the scenario interesting, not to win. A few things that actually matter once you're running live:

Pre-place, then react. Set up the opening disposition (enemy positions, patrols, objective defenders) before players finish their briefing. Once the op starts, you're reacting to what your squad does, not frantically building the world from scratch.

Pacing beats density. A platoon of AI dug in on a ridge, with a small reserve you release when the players flank, is more interesting than 200 AI milling around. Spawn in waves, despawn units that are no longer relevant, and give players quiet stretches between contacts so the loud moments land.

Possess things. Jumping into an AI sniper, a truck driver, or a squad leader for a few seconds is how you get behaviour that feels intentional. Use it to escalate a contact, cause a dramatic retreat, or make a vehicle do something its AI would never figure out on its own.

Stay in character on comms. "HQ reports movement to the north-east" is an order. "I've placed enemies at 045,089" is a spoiler. Push orders through an in-game radio channel or Discord, keep the GM view mute to the players, and let your squad discover the scenario.

Read the room. If your squad is steamrolling, trickle in a QRF or call in a technical. If they're pinned and losing morale, thin out the defenders or have the enemy withdraw to a new line. The scenario should feel hard, not unfair.

Game Master Enhanced

The one mod worth naming in a GM article is Game Master Enhanced (GME) by the zen-mod team, Workshop ID 5964E0B3BB7410CE. It's a quality-of-life layer on top of the base GM interface: AI formation and stance controls, waypoint cycling, object damage toggles, and MP save/load so you can checkpoint a long op and resume later. It is not a new asset pack and it doesn't add new factions – anyone selling it that way on YouTube is overselling it.

If you want to run GME, install it the same way as any other Workshop mod. The full walkthrough is in our mods install guide, which covers the mods block in config.json and mod IDs.

A quick platform note while we're on mods: since Update 1.4 (May 2025), PS5 supports mods on Reforger alongside PC and Xbox. Individual script-heavy mods can still be flagged PC or PC/Xbox only by their authors because of Sony's scripting restriction, but a pure-asset mod like most GME features will load for a crossplay squad. Don't assume your PS5 players are locked out until you've actually checked the mod's platform flags on the Workshop page.

A reasonable first op

If this is your first time running Game Master for a group, pick something small. A single-objective town clearance with 8 to 12 players, a light defensive garrison, and one scripted QRF you release when the players hit the centre of town is enough to run a full hour and let you get comfortable with the interface without drowning. Scale up once you've done two or three of those and know where your own limits are.

That's really the whole loop: set the scenario, #login, place the opening disposition, direct the mission, call the extract. The rest is taste.