In all the fuss and mess of the disastrous SimCity launch, one refrain has been repeated again and again. While legions may be begging for an offline mode, EA representatives have been abundantly clear that this simply isn’t possible. Maxis’ studio head, Lucy Bradshaw, has told both Polygon and Kotaku that they “offload a significant amount of the calculations to our servers”, and that it would take “a significant amount of engineering work from our team to rewrite the game” for single player.

A SimCity developer has got in touch with RPS to tell us that at least the first of these statements is not true. He claimed that the server is not handling calculations for non-social aspects of running the game, and that engineering a single-player mode would require minimal effort.

Our source, who we have verified worked directly on the project but obviously wishes to remain anonymous, has first-hand knowledge of how the game works. He has made it absolutely clear to us that this repeated claim of server-side calculations is at odds with the reality of the project he worked on. Our source explains:

“The servers are not handling any of the computation done to simulate the city you are playing. They are still acting as servers, doing some amount of computation to route messages of various types between both players and cities. As well, they’re doing cloud storage of save games, interfacing with Origin, and all of that. But for the game itself? No, they’re not doing anything. I have no idea why they’re claiming otherwise. It’s possible that Bradshaw misunderstood or was misinformed, but otherwise I’m clueless.”

People were already perplexed by EA’s explanation of the impossibility of offline play. Kotaku ran a series of tests today, seeing how the game could run without an internet connection, finding it was happy for around 20 minutes before it realised it wasn’t syncing to the servers. Something which would surely be impossible were the servers co-running the game itself. Markus “Notch” Persson just tweeted to his million followers that he managed to play offline too, despite EA’s claims. And now with the information from our source, it would seem the claims just don’t hold water.

So what are the servers doing? Well, alongside the obvious, of being involved in allowing players to share the same maps for their cities, and processing imports and exports between them, they’re really there to check that players aren’t cheating or hacking. However, these checks aren’t in real-time – in fact, they might take a few minutes, so couldn’t be directly involved in your game.

“Because of the way Glassbox was designed, simulation data had to go through a different pathway. The game would regularly pass updates to the server, and then the server would stick those messages in a huge queue along with the messages from everyone else playing. The server pulls messages off the queue, farms them out to other servers to be processed and then those servers send you a package of updates back. The amount of time it could take for you to get a server update responding to something you’ve just done in the game could be as long as a few minutes. This is why they disabled Cheetah mode, by the way, to reduce by half the number of updates coming into the queue.”

Clearly an offline game that included a single-player simulation of the region system derived from multiplayer would be more challenging to develop, but our source assured us that it was far from impossible.

So how difficult would it be for EA to create a single-player game that simply did away with the multiplayer-derived aspects and just let us build? It seems that lies somewhere between “easy peasy” and Bradshaw’s claims of “significant engineering”. According to our source:

“It wouldn’t take very much engineering to give you a limited single-player game without all the nifty region stuff.”

EA’s claims about the necessity of online play – claims that more people are seeing for themselves not to be true, just by running the game with the internet cable yanked out – seem inexplicable.

We’d obviously be very interested to hear a proper explanation.