OK, another idiot question which I just don't have time to playtest: Does obsolescence occur in your cities when someone else discovers the obsoleting tech? In other words, if someone else discovers the tech to obsolete castles, do I lose my trade route bonus? Or do I keep it until *I* get the tech myself somehow?
TIA all...
The obsolesence occurs when YOU get the tech. So Monuments and Stonehedge keep working until YOU learn Calendar. That's the obsolesence example that most often affects my game.