"The whole game is built around nations," explained Reynolds. "So we've added borders, we've added new rules for what happens to units outside of borders. You can't build inside an enemy's borders, so that affects how resources are gathered. You can also take over territory in a non-violent way. You can build a new city in unclaimed (non-bordered) land and turn that into your nation's color."
More akin to turn-based titles like Alpha Centauri or Civ III, borders expand as you build new town centers, and it's only when you claim the territory that materials are on can you start gathering them. In the demo, Reynolds showed us how a merchant unit can wander over to a mine, along with an animation that shows him setting up camp and mining the material.