In Key to the City – London, each player aims to develop their own London borough based on their home tile, using the large hexagonal location tiles. Each location tile gives victory points and may generate resources (skill tiles or connectors that connect two location tiles). Connectors and skill tiles can be used to upgrade location tiles for additional victory points and productivity.
The game is played over four eras, and in each era, new location tiles will be available for bidding. In both era 1 and 2, these tiles consist of six resource-generating tiles, plus some additional building tiles. In era 3, there will be only building tiles, which arrive already upgraded. In era 4, some of the Routemaster tiles become available.