During his keynote at the DICE Summit 2025, Diablo franchise general manager Rod Fergusson didn’t spotlight the series’ victories. Instead, he chose to reflect on one of its most infamous setbacks—Error 37.
For those who lived through it, Error 37 was a notorious issue that plagued the launch of *Diablo 3*, preventing players from logging in due to overwhelming server congestion. The error became a symbol of Blizzard’s rocky start to the game’s release, sparking widespread frustration and even spawning memes across the internet. While Blizzard eventually resolved the problem and *Diablo 3* went on to become a long-term success, the experience left a lasting impression on the team.
Fergusson made it clear that avoiding such issues is a top priority moving forward—especially as *Diablo* transitions into a full-scale live service model. With *Diablo 4* embracing ongoing seasonal updates, regular content drops, and future expansions, the franchise has entered a new era. Another large-scale failure like Error 37 could be devastating—not just for player trust, but for the game’s long-term viability as a live service juggernaut.
The Road to Resilience
At the DICE Summit in Las Vegas, I spoke with Fergusson after his session titled “Evolving Sanctuary: Building a Resilient Live-Service Game in Diablo IV.” In his talk, he outlined four key pillars for ensuring *Diablo 4* remains stable and engaging over time: scaling infrastructure effectively, maintaining a steady flow of fresh content, staying flexible with design philosophies, and prioritizing transparency with players—even if it means sacrificing surprise.
This approach marks a significant shift from how previous *Diablo* games were handled. While earlier entries in the series saw major updates and expansions spaced years apart, *Diablo 4* operates on a much faster, more continuous cycle. The result is a game built not just for launch, but for sustained growth and evolution over many years.
Is Diablo 4 Immortal?
I asked Fergusson directly: Is *Diablo 4* meant to last forever—or at least feel immortal? Will there ever be a point where the team shifts focus toward *Diablo 5*, or is this the definitive *Diablo* experience going forward?
“Maybe not forever,” he replied, “but certainly for a very long time, if we have our way.”
He emphasized the importance of giving players visibility into the game’s long-term vision. After all, *Diablo* players often invest hundreds of hours into their characters and worlds. Providing a clear roadmap helps reassure them that their time is valued and that Blizzard isn’t planning to vanish overnight.
Fergusson also reflected on the decade-long gaps between *Diablo 2* and *Diablo 3*, and then again between *Diablo 3* and *Diablo 4*. He acknowledged that while those games weren’t designed around constant updates, *Diablo 4* is built for longevity—and he joined the team too late to influence those earlier cycles.
“I learned my lesson about calling the shot too early,” he said. During his talk, he had originally announced that *Diablo 4’s* second expansion, *Vessel of Hatred*, would arrive in 2026. However, delays occurred when the team redirected resources to address urgent post-launch needs and support the first season. The gap stretched to 18 months instead of the planned 12. Now, Fergusson is cautious about setting expectations too far in advance.
“So I think giving, ‘Hey, you can relax for the next 11 months,’ is about as far as I want to go in this right now…We're not at a place where we want to put a stake in the ground and call it. Because we're still building it and learning from it.”
Ruin the Surprise for the Greater Good
Part of this strategy includes unprecedented transparency—like publishing detailed content roadmaps (set to debut in April) and expanding access to the Public Test Realm (PTR), where players can test upcoming features before they go live.
Initially, the team was hesitant. There was concern that revealing too much ahead of time would spoil the fun for players. But Fergusson now sees value in controlled spoilers.
“It's better to ruin the surprise for 10,000 people so that millions of people have a great season,” he explained. “Even if you mess up PTR, it's better than launching something broken and having to fix it over three months.”
He added that the team has grown more comfortable with the idea, especially after seeing how limited data leaks actually are in scope. “If something gets data mined, maybe 8,000 Reddit users see it—but we’re talking about millions of players. So it’s okay. We haven’t ruined the surprise for everyone.”
One current limitation is that the PTR is only available to PC players via Battle.net. Console access is restricted due to certification hurdles, but Fergusson confirmed that Blizzard is investing in broader availability, aided by Xbox’s support.
Growing the Player Base
Another benefit of Xbox ownership, according to Fergusson, is *Diablo 4’s* presence on Game Pass. This distribution channel removes financial barriers and allows the game to reach a wider audience—an advantage similar to releasing the game on Steam alongside Battle.net.
“With a premium live service like Diablo, versus a free-to-play model like Diablo Immortal, there’s a natural barrier to entry,” he explained. “Game Pass eliminates that. You get new players coming in constantly because they just say, ‘Oh, cool, that’s in here?’ And off they go.”
All Hours Diablo
As our conversation wrapped up, I asked Fergusson what he’s been playing lately. Naturally, *Diablo 4* topped his list. He shared that he’s logged over 650 hours on his personal account alone—not counting playtime during work hours. His current favorite class is the Companion Druid, though he recently started a Dance of Knives Rogue build.
When asked about comparisons between *Diablo 4* and *Path of Exile 2*, Fergusson noted that while both games share some genre similarities, they ultimately cater to different experiences. Still, he’s aware of how players juggle multiple live-service titles.
“A lot of people tell us, ‘Do what you're going to do, but just don't line up your seasons on top of each other. Let me play one season for three weeks and another for three weeks.’ As someone who plays a lot of games myself, I totally understand that.”
His top three games of 2024 by playtime include NHL 24 (third), Destiny 2 (second), and naturally, *Diablo 4* (first). Despite playing through Cyberpunk, Witcher 3, and Space Marines 2000, Fergusson always finds himself returning to *Diablo*—a habit formed from years of loving the game.
“It's something about the habit of the game,” he said. “I get interrupted by shiny things, but I always come back. The reason I came to Diablo five years ago was because it was my favorite game to play. And working on it hasn’t stopped me from going home and playing it for hours and hours.”
