According to a new blog post over at the official site for SimCity, lead engineer Simon Fox says that transitioning the once always online city building simulation into an offline game has taken him and his team six months to complete.
"[O]ur entire architecture was written to support [networked play], from the way that the simulation works to the way that you communicate across a region of cities," Fox said. "So yes, while someone was able to remove the 'time check' shortly after launch, they were unable to perform key actions like communicating with other cities that they had created locally, or with the rest of their region(s), or even saving the current state of their cities."
Fox explained that the original game relied on communicating with servers for region status and other information via a Java-based system. Letting this information be distributed offline meant rewriting the entire system in C++, he claims.
"Even things that seem trivial, like the way that cities are saved and loaded, had to be completely reworked in order to make this feature function correctly," Fox added.
The offline mode will arrive with SimCity's Update 10, which is coming very soon. The update will also allow offline players to install and use mods, though they are limited to cosmetic customizations.