In the file GalCiv3MapDefs.xlm you have a tag called <DefaultPlanetClassSelect>... here you can set the class and what weight these have when the a habitable planet are generated on the map. My problem is that these values are not used and whatever I select here don't seem to be used.
Could someone point me in the right direction where the weight in what class a habitable planet will be or perhaps there is a bug in place here?