Installing mods

Arma 3 mods load via command-line -mod= parameters. Both server and client need matching mods.

Where mods live

/data/arma3/ is the install root. Mods can be:

• Workshop mods — folders named @<modname> in /data/arma3/!Workshop/ (with the leading ! so they sort to the top of the file listing in the official tooling)
• Manual mods — folders named @<modname> placed anywhere in /data/arma3/ (root or a subfolder)

Adding a Workshop mod

1. Stop the server.
2. Find the mod on the Arma 3 Workshop. Copy its Workshop ID (the ?id= number in the URL).
3. Use SteamCMD or the panel's mod manager to download:

   steamcmd +force_install_dir /data/arma3 +login anonymous +workshop_download_item 107410 <workshop-id> validate +quit
   

   (Anonymous works for most public mods. A small set require an authenticated Steam login.)
4. The downloaded mod lands in /data/arma3/steamapps/workshop/content/107410/<workshop-id>/. Symlink (or copy) it to /data/arma3/@<modname>/ so the startup command can find it.
5. Add -mod=@<modname>; to the startup parameters in the panel.
6. Start. The server loads with the mod active.

For multiple mods, semicolon-separate:

-mod=@CBA_A3;@ace;@RHSAFRF;@RHSUSAF;

Server-side-only mods

Some mods only need to be on the server (anti-cheat, persistence, admin tools, headless client compatibility). Use -serverMod= instead of -mod=:

-serverMod=@adminTools;@persistence;

Server-only mods don't appear on the client's required-mods list — players don't need them locally.

Loadout — the "Modset" approach

The Arma 3 launcher lets players save and share modsets as .html or preset files. Publish your server's required modset on your community page; players import it into their launcher and the launcher auto-subscribes them to the right Workshop items.

Signed mods + signature checks

verifySignatures = 2; in server.cfg requires every mod to be signed. Each mod ships with a .bisign file per addon .pbo and a public key.

To allow a mod:

1. Find its .bikey file (in the mod's Keys/ folder).
2. Copy it to /data/arma3/keys/.
3. Restart the server.

If verifySignatures is on and you forget to copy a key, the mod can't load (server kicks players using it).

Common mod stack

Most servers run some flavor of:

• CBA_A3 — Community Base Addons. Required by almost everything else.
• ACE3 — Advanced Combat Environment. Realism overhaul.
• RHS — Red Hammer Studios factions (AFRF, USAF, GREF, SAF).
• TFAR / ACRE2 — Radio system (TaskForce Radio or ACRE2).
• CUP — Community Upgrade Project (Arma 2 ports).

CBA must be earliest in the -mod= chain because everything else depends on it.