SimCity’s Always Online Mode Is Only Necessary For DRM
EA’s Lucy Bradshaw claimed that SimCity is fully dependent upon its online servers to play the game. This is only true to the extent that the game is unplayable due to the fact that the client requires an always-online connection as a form of DRM and not necessarily because the simulation is run through the servers. The DRM functions as a sort of heartbeat to check if the player is connected to the server. In an interview with Polygon, Bradshaw said that the developers “identified that many of our issues were related to how [SimCity's] GlassBox [engine] managed the vast amount of simulation data through its database.” She argued that it wouldn’t be possible for the developers to implement an offline mode without a significant amount of engineering.
However observant players on reddit have noticed that it is possible to play SimCity up to ten minutes without an online connection, as the game’s client only syncs up with the servers ever so often. The game would be playable offline (sans social features) were it not for the fact that the player is kicked out if the client does not detect an internet connection.
The GlassBox engine runs most, if not all of its city simulation locally on the client machine and not on the servers, and would continue to do so even if you were offline. As a matter of fact, the only real computation done server-side is the region computation (including commuters and trading), which has been confirmed by the game’s lead designer Ocean Quigley. Beyond that, the servers are only responsible for cloud saves, and its social features such as leaderboards and achievements—both of which have been disabled for now.
To that end, a user going by “DBrickShaw” has put together a working theory of how the processing responsibilities are distributed between the game’s client and server in an extensively well-researched post on reddit. He writes:
- Speaking from a purely technical standpoint, it is simply not feasible to continually distribute the amount of data required to perform routing calculations for hundreds of thousands of individual agents in real time over the vast majority of internet connections available today. If any of the AI agent simulation was being done on the server side SimCity would use significantly more bandwidth than it does during gameplay, and gameplay would be significantly impacted when the connection was lost. As those who’ve fought through the last few days can attest, you can lose your connection to the EA/Maxis servers for hours at a time and the intra-city gameplay keeps working perfectly fine.
- Cities which are not being actively played show no signs whatsoever of intra-city development. Zoned land does not develop. The number of jobs, workers, and services provided by the city don’t change. Industrial resources are not produced, and ore/coal/oil deposits are not exhausted. When you stop playing a city only a static snapshot of the city and the services it provides are saved to the server.
He argues that the servers are not handling most, if any local simulation and that SimCity would be playable offline should EA ever decide to release an offline mode.
It is safe to say that if the game was performing real-time data uploads and computations, most players’ wouldn’t have connections good enough to stream the data to begin with.