The campaign is divided up among the dynasties that have ruled China, the challenge increasing correspondingly as you serve the different dynasties:
Xia Dynasty 2070 – 1600 BC (tutorial campaign)
Shang Dynasty 1600-1046 BC
Zhou Dynasty 1046-221 BC
Qin Dynasty 221-206 BC
Han Dynasty 206 BC – 220 AD
Sui-Tang Dynasty 581 – 907 AD
Song Jin Dynasty 960 – 1234 AD
The game also offers a sandbox mode in which there are no objectives to be fulfilled.
Like other city-building games by Impressions, Emperor requires you to pay homage to your people's religious figures. In the early years, the Ancestors will be the sole focus of your people's religion, but as the game progresses Confucianism, Daoism and Buddhism will appear as well, along with some of their major figures, including Confucius himself.
Emperor allows you to interact with other major cities in China (and later Tibet and Korea as well). Interaction includes trade, espionage, pacts and warfare. It is possible to occupy other cities for tribute, either in cash or resources specific to their area. Some missions will require you to control multiple cities to complete your objectives. Conversely, you can also be occupied by a rival city if they defeat your defending forces. This will not end the mission, but refusal to pay tribute will spark another invasion which, if successful, will permanently remove you from power.
During the campaign you will have to face rival Chinese cities, Xiongnu and Mongols, among others, on the battlefield. If you are defending your own city, you will be allowed full control of your forces to repel the invasion. If you are on the offensive, you cannot control the battle and the result will be reported to you. The religious figures mentioned above can be summoned to participate either in the defense or the offensive, if their favour is high enough.
Emperor was the first city-building game to offer multiplayer possibilities.