
Both of these costs increase with the number of (active) great works already existing within the realm: 40% more gold per great work, and an additional 80% increase for each great work of the same type. Great works have a base construction cost and a monthly construction cost. Each stage grants 2 feature slots, which allow the ruler to customize the benefits of their great work, up to 8 slots at the maximum level. Once the first level has been completed it is possible to upgrade up to level 4 with additional features, some of which are generic across all great works and some of which are specific to the type of great work you are building.

From there, the player may select from a set of available great work options. Great works can be built in any province by clicking the "View great work construction" button on the province menu.
