Empire is a turn-based 4X wargame, where players command armies of
units which they use to explore the game world, control territory, and
attack opponents. The game world consists of "sectors", which may be
designated as agricultural, industrial, etc. Control of these sectors
grants the player a variety of raw and manufactured materials, which
they may use to construct dozens of unit types.

In each round, the players submit their commands for the activities of
their units to the central server, which executes all of the commands
either simultaneously or in a sequence. Rounds can last anywhere from
a few hours to a day. As such, a full game can take much longer than
modern 4X games, depending on the size of the game world; "Blitz" games
may last a few hours, while typical games last months and larger games
can take up to a year to complete.