The Multiplayer button in the game takes you to LAN play online. You need to click the Ironclad Online button, then create an acocunt for it, to play over the Internet.
The CD Key it asks for will be the serial number that was sent to you via email when you ordered the game. If you do not have it, you can retrieve your serial number(s)
here.
The serial number also gives you the ability to download the patches, which you will need to connect to Ironclad Online. Current version is 1.05.
-HM
