Cities: Skylines expansion After Dark will be out late next month

Paradox Interactive has announced that the Cities: Skylines nighttime expansion After Dark will be out on September 24, with a price tag of $15. Developer Colossal Order has also posted the first in a planned series of dev diaries explaining why there's a lot more involved with making the expansion than simply turning down the lights.

"Taking the cities from daytime to night is not as simple as one might think," Lead Designer Karoliina Korppoo wrote. "While the change from day to night is visually stunning, there's much more going on under the hood. Each and every building in the game received a new texture layer to have the windows light up nicely. In addition there are new lighted signs, neon signs and other lights to make the city look interesting during the night."

Changes to the underlying city simulation will more realistically depict the slower pace of the night. Most people stay indoors, and those who do go out tend to head for entertainment hot spots. The lighter traffic makes the night an ideal time for services like garbage pickup and road construction, but crime will also increase. Dealing with these issues will be made somewhat easier through the addition of a separate "night time budget," which will enable time-based scheduling of services, such as bus lines that only run at night.

"The night time creates new challenges and changes the way traffic behaves to alter the way the city works," Korppoo wrote. "We want to create more variation to the game and make the cities feel alive, with ever-changing needs and a constant, but changing, stream of citizens traveling to their desired destinations."

Publisher Paradox Interactive said at Gamescom last week that Cities: Skylines will follow the same expansion strategy as its Europa Universalis and Crusader Kings games: The paid expansion will be accompanied by a "major patch with free content," although what it will include hasn't yet been revealed.