SimCity will soon be playable in offline mode, developer EA Maxis announced this week, 10 months after saying it couldn't be done "without a significant amount of engineering work."

The studio will add offline mode for all players with Update 10, a free upcoming patch. Once the single-player mode is added to the game, all previously downloaded content will be accessible without an internet connection, and SimCity will store single-player save games locally instead of in the cloud.

Maxis is "in the late phases" of development on offline mode, and the studio plans to run extensive testing on it before launching it, said Patrick Buechner, general manager of Maxis Emeryville, in a post on the game's blog. "Our priority is to make sure that it’s as polished as possible before we release it," he added. Maxis will initially open up offline mode to a handful of hardcore SimCity players that the studio refers to as "DevTesters," and will soon put up another blog post with further details on the mode.

offline mode is "in the late phases" of development

In an interview with Polygon days after SimCity's release in March 2013, Maxis' then-general manager, Lucy Bradshaw, said that it wouldn't be impossible to build an offline mode into the game, but it would require "a significant amount of engineering work by our team." Last October, Buechner said Maxis was exploring the possibility of adding an offline mode to SimCity, but made no promises.

At the time, Bradshaw described the online requirement as "fundamental to the vision we had for this SimCity." According to Bradshaw, Maxis built the game to offload aspects of the city simulation into the cloud so they didn't have to be processed locally. In addition, said Bradshaw, SimCity was designed to foster communication and resource exchange between multiple players' cities — Maxis wanted to "explore the dynamics between cities as they exist within regions," she told Polygon.

Many players never got to experience that multiplayer gameplay as Maxis intended. SimCity suffered a disastrous launch last March, with the game crippled for weeks by server issues that persisted even as Maxis disabled game functionality. Bradshaw told Polygon that in addition to the servers being overwhelmed by unanticipated demand, SimCity exhibited different performance under the stress of live servers than in the studio's testing.

Shortly after SimCity's release, two players debunked Bradshaw's statements about the game offloading calculations to the cloud. They told Polygon they had examined the data that traveled back and forth between their computer and EA's servers, and determined, "It's not possible that EA servers are 'offloading' calculations (simulations) for your city."

SimCity was crippled for weeks after launch

The debut of offline mode "means big things for our wonderful community of modders," said Buechner this week. "They can now make modifications to the game and its components without compromising the integrity of the online game. Modding is a big part of our studio’s legacy and we’re excited to see what you guys create." Yesterday, Maxis outlined modding guidelines for SimCity, including prohibitions on modifying multiplayer content and selling mods.

"From me, and everyone at the studio, thank you again for staying with us. We look forward to getting offline for SimCity into your hands as soon as possible," said Buechner.