Crazy George
Destined to Rule
I like this idea.
One could certainly program CIV5 so it would be harder to culture pop a tile on the other side of a mountain range or a river. And between the high cost for one civilation and the therefor lower cost to the other, the river or mountain range would make the logical border.
From what I understand something like this will probably happen at Mountains and Deserts anyway, in that desirable tiles are supposed to pop before undesireable ones, and Desert tiles are certainly among the most undesirable in my book. So, expansion through the deserts would be the slowest (and thus where two Civs are most likely to meet).
As an additional thought, I'm guessing upkeep for units will increase in Neutral or Hostile territory (versus one's own territory). But since pacification of the natives is a function of a military presence and exploratory expeditions often precede settlement (see Lewis and Clark), the presence of a unit in neutral territory should increase the chance of that tile popping.
For example, if my archer is sitting on a neutral iron deposit, I'm clearly making a claim to that resource. Sort of unfair to let the AI pop it from underneath me at that point.
