Speaking at GDC Online yesterday, Blizzard has revealed that the second generation of multiplayer service and social network Battle.Net is one of the developer's biggest projects unto itself.
Nominally a part of StarCraft 2, the service is also paired with World of Warcraft and likely to play a part in future titles such as Diablo III.
"This is easily the most complicated launch I've been a part of at Blizzard," said Battle.Net technical director Matthew Verslyus in the talk attended by Gamasutra.
"Blizzard is a company that back in say 2002, 2003, when we were launching Warcraft III, that's the last time the company shipped a non-MMO boxed product.
"It really was an adjustment for us, thinking beyond the MMO."
Added project director Greg Canessa, "Integrating with a community of 12 million users and not screwing it up is a huge challenge.
"Integrating a game service and an MMO is just challenging from a technical and compatibility standpoint across the board."
Canessa also warned developers of other game networks not to underestimate the scale of such projects. "It's really hard designing and building this stuff... It's really, really expensive to go this route."
While he claimed that designing a network like Battle.Net was as complicated as designing the games it would support, "Launching the service is just the beginning. I can't emphasis this point enough."
With Blizzard yesterday revealing World of Warcraft now exceeds 12 million subscribers and with the knowledge that StarCraft II shifting 3 million units in its first month on sale, the userbase for Battle.Net is likely significantly higher than Canessa and Verslyus intimated.