Blizzard is "confident" that Diablo IV's launch servers can handle the load

Further Reading

That quoted vote of confidence comes from Diablo IV Art Director John Mueller, who told Eurogamer that the game's March beta tests and recent "Server Slam" test weekend gave the team valuable perspective on how the game's infrastructure will function when millions of early adopters try to log in at once on June 5 (or June 2 if you paid for early access).

"It's not a marketing thing," Mueller said of the beta tests. "It's really about getting that information so we know day one is going to be as good as we can possibly make it and that we just feel confident going in. So, currently right now, we feel really confident."

Associate Game Director Joe Piepiora echoed that sentiment to Eurogamer, adding that before the betas, the team spent over a year testing the servers with automated bots performing simple in-game tasks. But Piepiora said that testing with real players logging in provided more valuable and actionable data for testing purposes.

"When you have people coming through different ISPs and coming in through different servers around the world, there's so much more data you get from that," he said. "And with each of those we found lots of little things that happen, like this happens with clan invitations, this happens when you join a party in a certain way, lots of little things like that across the board."

Much like its predecessor, Diablo IV requires even solo players to log in to the game's persistent servers to play. And after many players faced hours-long queues and server disconnections during Diablo IV's first "early access" beta in mid-March, the company told players to expect that there would be "lengthy queue times" for the game's late March open beta.

But queueing times for that second test were reportedly noticeably shorter than they had been weeks before. And last weekend's "server slam" beta test featured servers that didn't seem especially slammed and very few reports of long queue times or login problems (the simultaneous launch of a certain Zelda game may have helped lighten the weekend load).

"We ended up doing six really big hotfixes that fixed dozens of issues," Diablo General Manager Rod Fergusson told Eurogamer regarding early queueing issues for that first March early access beta. "So we saw server stability come back up and the queues went down, and so we're feeling really good about that particular aspect."