To be able to play a multiplayer game of Age of Empires 3, either over the Internet or on a local network, you must ensure that your router is configured to keep the particular ports open for the game to use. If you don’t set up your router to open these ports, you may get a “Failed to Join Game” message. This configuration is called port forwarding and is set up by accessing your router through a Web browser. Tips Warnings Writer Bio

How to Open Ports on My Router for  Age of Empires 3  - 95