In Empire Earth I Edit
In Empire Earth II Edit
There are two types of resources: the main resources which are available in all epochs, and the special resources, which become available only in certain epochs.
For the special resources, each of them is gathered according to the epoch the player is in currently, Tin becomes available in Epochs 1 through 6 and can be mined. Iron becomes available through Epochs 4 through 9 and can be mined, too. Saltpeter becomes available in Epochs 7 through 12 and can also be mined. Oil becomes available in Epochs 10 through 15; however, the player must build Oil Derricks and garrison citizens to gather the resource. Uranium becomes available in Epochs 13 through 15, but instead of building Oil Derricks, the player has to build Uranium Mines and garrison citizens to gather the resource.