How to Use Headless Client with Your Arma 3 Server

Published 9 June 2026 · By Host Havoc Technical Support Team

The Arma 3 headless client (HC) offloads AI processing from the main game server to a separate instance, reducing server load. There are two ways to use this feature with a Host Havoc server.

Before configuring anything, review the official Bohemia Interactive wiki article on headless clients and confirm your mission is designed to use one. Misconfigured files, firewall rules, or a mission that does not support HC will prevent the connection from working. For related configuration work, see configure RCON.

Before you start: Common barriers include firewall rules blocking connections, antivirus software blocking the program, misconfigured config files, and missions not designed for headless client use.

Option 1: Use your Host Havoc server as the headless client

Use this option when you want your Host Havoc Arma 3 server to connect as an HC to a separate game server instance.

  1. Log in to the Game Control Panel and navigate to your server.
  2. Click the More icon to the right of the Start/Restart buttons.
  3. In the More section, click Change to HC/Arma 3 server and choose Headless Client, then click Run.
  4. Navigate to the Command Line Manager and create a custom command line if you have not already done so.
  5. Fill in the Client Connect info field with the IP and port of the target server in IP:PORT format. For example: 123.123.123.123:2300.
  6. Save the command line and click Select on the right-hand side of the command line manager.

Option 2: Connect an external instance as HC to your Host Havoc server

Use this option when you want a separate HC instance to connect into your Host Havoc Arma 3 server.

  1. Log in to the Game Control Panel and navigate to your server.
  2. Open the Configuration Files menu.
  3. Open the server.cfg file in the text editor.
  4. Add a headlessClients[] array to the file, listing the headless client's IP address. Refer to the official wiki for the correct syntax.
  5. Confirm your mission supports headless clients.
  6. Save the file and restart the server.

Note: The external HC instance must be set up separately on its own machine or server. Host Havoc does not configure or manage external instances.