There is absolutely no reason to waste time on the vanilla version when you can have all the new units and features available in BTS.

The expansions add some enjoyable features and touch up some areas that needed it

The expansion pack adds on some great bonus features not available in just the Civ IV game.

One nice feature is that you don't have to leave the disk in your dvd drive after you install and when you want to play the game.

How about making it More fun to play, as well as having the ability to be turned UP, for those who have the xtra strong Gaming systems??Loved being able to get these Three flavors, of a Great version, for less than I paid for the One Newest Version