

Each level of settlement opens up one extra building slot and improves tax income, but also reduces happiness due to modernisation. This chain of buildings provides the foundations for the expansion of your settlements. This chain of buildings increases both wealth and town growth within a province. This chain of buildings enables the development of traditional Japanese methods of military training and units. Shinsengumi and ishin shishi agents can be recruited here. This chain of buildings allows you to set up a network for the spreading of Imperial or Shogunal influence throughout your territory. This chain of buildings enables the development of modern, western methods of military training and units.

This chain of buildings allows the specialisation in the cotton, crafts or silk industries, providing increases to both wealth and growth within a province.

All castles contain archer towers by default. This chain of buildings allows you to upgrade the tower defences of your castles independently from the castles themselves. It also enables the recruitment of geisha agents and increases their chances of success. This chain of buildings, the result of a general population surge as society moves away from agriculture to industry and city life, increases wealth and happiness. This chain of buildings improves your recruitment and replenishment capabilities, and can be specialised to improve the statistics of specific units. This chain of buildings enables the production of artillery pieces and the recruitment of their crews. They are also the chief consumer of food in a province, so if farm building levels are not in step with castle size there will be food shortages. Larger castles are more difficult to assault and spawn a larger defence force of samurai retainers and women.

Each level of castle building increases the size of its castle town: providing an additional slot on which to build, enabling the recruitment of basic ashigaru units and determining how many units can be recruited there in each turn. The castle is the heart of the population and public order's main controlling factor.
