A fan-modded version of "SimCity" can make the game playable without an internet connection.
According to publisher EA, "SimCity" requires a constant internet connection for both DRM and gameplay reasons. Players connect their cities with friends to create co-dependent "regions" that can take advantage of each other's strengths and help them overcome their weaknesses. In the retail version of the game, players aren't kicked out the moment they lose their connection: The disconnect timer triggers an automatic time out once a player has been offline for 20 minutes stright.
Created by modder UKAzzer, the mod simply disables the game's disconnect timer, allowing players to stay in that temporary offline state as long as they please. The mod also removes the game's so-called "fluffed" population, which makes cities seem more populated than they actually are. Lastly, a video of the mod in action shows that players can edit highways outside of a city's boundaries using the game's debug mode.
The mod isn't perfect though, without an internet connection, players lose the ability to save and cross-region play. While the mod seems simple, UKAzzer isn't completely sure whether it'd be possible to mod the game to the point where it would be 100 percent functional without an internet connection.
"...I'm experimenting with hacking in ways to spoof it into 'claiming' a city without sending that info to the server, loading that city data up from local data, and enabling editing, so you can edit a city and pick a region square all offline. Still don't think I can find any simple way to SAVE it yet, but it'll be a start. Whether I take it any further than that, or leave that to the real hardcore coders/hackers with more time on their hands, I don't know," he writes.
EA and Maxis have both stated that making the game completely playable without DRM would not be an easy fix. According to the creators, the game's servers handle a large number of the game's calculations. An anonymous Maxis employee, on the other hand, suggests the game's servers do much less than officially suggested. Regardless, EA currently has no plan to switch off the game's connectivity requirements.