by mrmikkl
Thanks so far. I just took a look into the rulebook.There are two special rules mentioned for terraforming.
The first one says that you can terraform another terrain with spades that were not used for the first one, but only if you were able to transform it into your home-terrain-type.
The second one says that you have the possibility to use spades on a terrain to transform it stepwise. This means that you can transform a terrain into a terrain-type that is not your home-terrain-type, so that in upcoming turns it will be easier for you to "fully" transform it.
I think that especially the first one is very interesting because the wording says that the first transformation has to be successful (meaning that you were able to transform it into your home-terrain-type) to enable you to transform a SECOND terrain with the left-over spades.