Empire City is a city-planning and world-building game that begins in a location that's part of the Roman Empire. The player receives the role of a regional official known as a Prefect. They use the guidance and help of innkeeper Julia, architect Flavius and others to perform actions that help them create and rule an empire.
The game walks the player through steps they should take to build up the city and expand the region. Through local characters and popups, for example, it prompts the player to install structures near access roads, build extensions to existing roads and new ones, upgrade existing structures, find, process and use raw materials, and create workshops to make innovative new materials. Flavius also provides the player with a scroll filled with recommendations categorized as Tasks, Projects, Forts, Orders and Reports.
Empire City initially helps the player buy structures. Once the player installs and upgrades one, they receive additional coins for future builds. Many of the tasks also require them to pay with green gems, such as tasking workshops to make materials and buying and clearing forests and meadows for city expansion.
The player receives coins, gems and other rewards in various ways. For example, they receive access to new types of structures, landscapes, tools and a few gems when they level up. Flavius promises that they will receive a special reward from the current emperor if they complete all of his recommendations. Additionally, the citizens give them daily chests that contain much-needed currency and items.