Kingdom (players could build roads in Rise of an Empire, but they were optional). Economy The first four titles in the series feature a broadly similar economic system built on a foundation of basic supply-and-demand, and in all four games, the player can control the economy in various rudimentary ways. For example, the player can adjust the distribution of goods by selecting which percentage of a given resource is transported to a given building. In a similar manner, the player can select what tools are made when, which is important insofar as all buildings require raw materials and a worker with the right tool. The economic systems in the Heritage of Kings, Rise of an Empire, and Paths to a Kingdom differ substantially from the first four games, and from one another. In Heritage, for example, the player must manage taxation. Serfs do not need lodgings, nor do they consume produce, but they also do not pay taxes. Workers, on the other hand, need both lodgings and sustenance (provided by farms), and the closer the lodgings and farm are to their workplace, the more productive they will be. A major change to the mechanics in Heritage of Kings is that unlike the previous four games, serfs no longer transport resources. Instead, resources are automatically deposited into the player's storehouse, and the various refinery workers collect the materials for processing themselves. In the case of construction, the necessary resources are automatically transferred to the build site without having to be physically transported. Another new feature is the ability to upgrade buildings, which can increase efficiency or capacity, grant access to new abilities, or allow access to new technologies. Rise of an Empire features a considerably streamlined economic model when compared to all previous titles, with the most basic production chains of any game in the series (usually involving only two buildings). A settler in a resource building will walk to the nearest source of raw materials, gather them, and return to his building. When the building is full, one of the settlers living there will take the resources to the storehouse. A settler in a produce building will then walk to the storehouse and bring the raw materials back to his building, using them to make finished goods, which are then sold from that same building. New to Rise of an Empire are needs and wants. Settlers in resource buildings have