I don't really like the idea of giving Rice Terrace to anyone; they exist, but they're not really prevalent except in the particularly hilly areas. It's not something that springs to my mind for any of the Mandala civs (remember that the Philippines is not part of this group) since generic paddy fields appear MUCH more often. I'm unsure how prevalent it is in the Orient.
As for rice fields, I don't quite like the idea either, they're simply too prevalent in Asia in general. There are much more unique features in each region that deserve to be represented (I'll be very disappointed if you opt to give the Mandala civs rice fields rather than showing off our fondness for Albino Elephants).
As for rice fields, I don't quite like the idea either, they're simply too prevalent in Asia in general. There are much more unique features in each region that deserve to be represented (I'll be very disappointed if you opt to give the Mandala civs rice fields rather than showing off our fondness for Albino Elephants).