Resources
Oil, gas, metals and food lie all over the world. Hold them and refine them for extra money.
Resource fields are dotted over every country. They show on the map when you zoom in, or at any zoom with the Resources map mode.
A field belongs to whoever has a standing army, fleet or base over it. Moving groups and aircraft do not hold fields, and when two nations cover the same field, nobody gets it.
A field only pays once its riches reach a Refinery by a supply route.
No field lasts forever. Fields run dry, and new ones turn up around the world: keep your eyes open.