It's about time we took a closer look at the districts and policies in Cities: Skylines. Without further ado grab the popcorn, find a comfortable seat and enjoy the ride!If you want to refresh your memory about the previous dev diaries, check here: http://forum.paradoxplaza.com/forum/showthread.php?802652-Cities-Skylines-dev-diary-archive In Cities: Skylines we wanted the cities to be big but we also wanted to give the player control over smaller parts of the city and make it possible to customize the different areas as they see fit. In addition we wanted to provide the possibility to create specialized industry and connect it to the functionality of what would become the districts.City and district policies are the natural companion to the creation of districts and they provide the tools to customize what happens in any of the districts, from setting service policies to affecting taxes and city planning such as banning highrise buildings and heavy traffic.Both the district feature and the different policies unlock as the city grows and the player progresses in the game. They make for great supporting tools to handle the larger cities that occupy many map tiles.At their core districts are areas that the player can create by painting them using the Paint District tool. Districts can be of any size and they can be used to simply create city boroughs that have distinct names like Manhattan and Bronx in New York or they can be used to fine tune a set of aspects from industrial types to the distribution of smoke detectors to lower the risk of house fires. When a district is created the game automatically gives it a name which can be changed at any point during the game.After a district is created the player can access its statistics which lists population numbers and the different age groups, average level for different zone types and the average land value in the district. Through this panel the player can access the policies for that particular district. The policies currently active are displayed in the district panel as well as under the district name on the map.There are two ways to set policies:City-wide policies are accessed and set by clicking the Policies button on the main UI, next to the Economy button. This applies all the set policies to the whole city, including any districts already created. Although the player can then adjust the districts individually.District policies are set by accessing the district panel by clicking the district name and from there clicking the Policies button. These policies affect only the district that is accessed when the policy is set.Policies are divided into four categories: Industrial specialization, Services, Taxation and City planning. Most of the policies can be set to both the whole city and districts with only the industrial specialization policies requiring always a district to apply it to. Policies usually have pros and cons depending the nature of the policy. For example, Power Usage policy decreases energy consumption but costs a little extra to the city since it has to set up energy meters and additional equipment to monitor the energy levels in buildings.Cities: Skylines features four industrial specialization policies that can be set by accessing the District tool and selecting one of the four policies and then clicking a district. When the policy is set, an icon appear both under the name of the district as well as in the district panel and the zoned industry starts to change to the set industry type. The District tool also features Generic industry option which reverts the specialized industry back to generic industry.Services policies affect the different city service areas of the city. One gives a boost to education while another distributes smoke detectors to all buildings.Taxation policies allows a more fine tuned approach to the tax rates of different zone types and densities.City planning affects how the city or particular district will look when these policies are in effect. For example, the player is able to ban highrise buildings and heavy traffic in an area or turn all residential buildings into smart buildings that increase the land value around them.- Henkka also known as an artist, designer and level designer at Colossal Order