With new epochs, some new units are available at the cost of having to abandon the ability to produce old units, though any old units still alive are kept. Epoch advancement requires additional buildings to be built and the costs of advancing increases as more epochs are attained, although the ability to gather the required resources greatly increases as well. Each epoch brings new technologies and units. In the Art of Conquest, a third future age, the Space Age, is available.
In Empire Earth, the last two ages (Digital and Nano Ages) are set into the moderate future (at the time of release in 2001). Each of these epochs represents an age within history. we Epochs are the ages a player passes through in Empire Earth.
Empire Earth is a strategy video game developed by Stainless Steel Studios and published by Sierra On-Line.It was released on Novemfor PC.