Rod Fergusson, Diablo general manager, kicked off his DICE Summit 2025 presentation not with a victory lap, but by addressing one of Diablo's most infamous setbacks: Error 37. This launch-day debacle for Diablo 3, caused by an overwhelming influx of players, resulted in widespread frustration and became a memorable internet meme. While Diablo 3 eventually triumphed, the experience underscored the importance of preventing similar catastrophes, especially with Diablo's evolution into a complex live-service model featuring frequent updates, seasons, and expansions.
The stakes are higher than ever for Diablo 4, which has fully embraced the live-service model. Another Error 37 would be devastating, especially if Blizzard aims for Diablo 4's longevity beyond its major content releases—a true live-service juggernaut.
Diablo, Immortal
At DICE Summit 2025 in Las Vegas, I spoke with Fergusson following his presentation, "Evolving Sanctuary: Building a Resilient Live-Service Game in Diablo IV." He highlighted four key elements for Diablo 4's resilience: scalable infrastructure, consistent content delivery, design flexibility, and proactive player communication. His emphasis on long-term player engagement contrasts sharply with previous Diablo titles. While expansions and updates were common, Diablo 4 represents a commitment to a live-service approach, enabling significant, ongoing changes and prolonged lifespan compared to the traditional numbered-release model.
I asked Fergusson about Diablo 4's long-term vision: is it aiming for eternity, or is there a planned transition to Diablo 5? His response suggested a very long lifespan, but not necessarily forever.
"We want it to be around for years," he stated. "I don't know if it's eternal. We want players to see a clear roadmap, because we understand their investment of hundreds of hours. We want to show respect for their time and demonstrate our commitment to the game's long-term support."
Fergusson pointed out the decade-long gaps between Diablo 2 and 3, and 3 and 4. However, those games lacked the aggressive update schedule planned for Diablo 4. His leadership, starting in 2020, brings a different perspective, emphasizing forward planning—but with a healthy dose of caution.
His DICE Summit announcement of Diablo 4's second expansion, delayed until 2026, exemplifies this caution. Initially slated for a yearly release, the timeline for "Vessel of Hatred" was extended due to diverting resources to critical live-game updates and the first season. The 18-month gap between Diablo 4's launch and "Vessel of Hatred" highlights this adjusted approach. When asked if this is the new standard, Fergusson remained non-committal, having learned from previous premature predictions.
"I learned my lesson about calling the shot too early. Giving an 11-month timeframe for the next update is about as far as I'm willing to go right now... We're not at a point where we want to publicly declare a set schedule. We're still building and learning."
Ruining the Surprise…on Purpose
Fergusson's caution is understandable, given the team's commitment to unprecedented transparency. This includes the upcoming April content roadmap and the Public Test Realm (PTR), allowing players to test upcoming patches before wider release. Fergusson initially hesitated about using a PTR or roadmap, fearing it would spoil surprises. He's since changed his mind.
"It's better to ruin the surprise for 10,000 people so that millions of people have a great season," he explained. "Even if the PTR reveals flaws, a bad week on the PTR is preferable to three months of recovery from a poorly received surprise update."
He's currently working to expand PTR access to consoles, hampered by certification challenges and the complexities of console releases. He's optimistic about progress with the support of parent company Xbox.
Fergusson also highlighted the benefits of Diablo 4's inclusion in Game Pass, removing a significant barrier to entry and attracting a continuous influx of new players. He compared this to the decision to release Diablo 4 on Steam in addition to Battle.net—both are about maximizing player reach.
"A premium live service like Diablo faces different growth challenges compared to a free-to-play title like Diablo Immortal. Game Pass eliminates the barrier of purchasing the game, allowing us to consistently reach new players who discover the game through their Game Pass subscription."
All Hours Diablo
In closing, I asked Fergusson about his recent gaming habits. He shared his top three games of 2024 by playtime: NHL 24 (third), Destiny 2 (second), and Diablo 4 (first, with 650 hours on his personal account, excluding work). He currently plays a Companion Druid and recently started a Dance of Knives Rogue, showcasing his enduring passion for the game.
"It's a habit," he explained. "I get sidetracked by other games, but I always come back to Diablo. I have daily routines in other games, and Diablo is just…my favorite game. Working on it doesn't stop me from playing it for hours at home."
