imo terraforming is the most powerful spell against AI, it literally gives the player power of the creator, ability to adjust the world around. With terraforming we can build up mountain barrier shielding cities from powerful enemies and create shortcut towards opponents' heartland. however, i do realize terraforming will destroy whatever resources on the original tile. My question is, will it destroy the hidden resources as well? e.g. the monster lair activated by researching cooperation/diplomacy, how are these resources' locations chosen? are they decided right after game start or after finishing the research of necessary tech?