The game allows players to create a region of land by terraforming, and then to design and build a settlement which can grow into a city. Players can zone different areas of land as commercial, industrial, or residential development, as well as build and maintain public services, transport and utilities. For the success of a city, players must manage its finances, environment, and quality of life for its residents. "SimCity 4" introduces night and day cycles and other special effects for the first time in the "SimCity" series. External tools such as the Building Architect Tool (BAT) allow custom third-party buildings and content to be added to the gameplay.