This is probably something that should be achieved by map / scenario / mod design ? In fact since this is a common request, I keep seeing people implementing i

This is probably something that should be achieved by map / scenario / mod design ? In fact since this is a common request, I keep seeing people implementing it in all kinds of games, I would be surprised if nobody in the Civ community had never set this up and shared across the whole 6+2 games franchise ?