Installing Beyond the Sword will patch your version of
vanilla. This will make it incompatible with our current game. You can find more information on this in various sub-forums, like the multi-player forum and the GOTM forum. It is possible to make a dual-install though, instructions can be found in various places, just ask it in the technical support forum when you get the game.
![Civ4 [civ4] [civ4]](/images/smilies/civ4.gif)