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 overwhelming player numbers, resulted in widespread criticism and became a lasting meme. While Diablo 3 ultimately triumphed, the experience underscored the importance of preventing similar catastrophes, especially given Diablo's evolution into a complex live-service game with 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 to endure 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 crucial 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 model, allowing for significant, rapid changes over a much longer lifespan than previous numbered entries.
I asked Fergusson about Diablo 4's longevity—is it aiming for immortality? Is there a benchmark for moving on to Diablo 5, or will Diablo 4 remain the definitive Diablo experience, akin to World of Warcraft?
Fergusson envisions a long, but not necessarily eternal, lifespan. "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, respecting their investment of hundreds of hours. We're committed to the long haul."
He pointed out the decade-long gaps between Diablo 2 and 3, and 3 and 4, acknowledging the difference in update frequency. However, his arrival in 2020 brought a new perspective, emphasizing forward planning, but with a healthy dose of caution. He learned a valuable lesson about premature predictions.
For example, Fergusson announced at DICE Summit that Diablo 4's second expansion wouldn't arrive until 2026, an extension from the initial yearly schedule. This delay stemmed from prioritizing urgent live game updates post-launch and during the first season. The 18-month gap between Diablo 4's launch and Vessel of Hatred, instead of the planned 12, taught him valuable lessons about setting expectations.
"I learned my lesson about calling the shot too early," he admitted. "Giving players an 11-month timeframe is about as far as I'm comfortable going right now. We're still building and learning. We'll announce publicly when we have the certainty to do so."
Ruining the Surprise…on Purpose
Fergusson's caution is understandable, particularly given the team's increased transparency. This includes an upcoming content roadmap (April release) and the Public Test Realm (PTR), allowing players to test patches before public release. Initially, the team hesitated about using a PTR or roadmaps, fearing spoilers. However, Fergusson shifted his perspective.
"It's better to ruin the surprise for 10,000 people so that millions of people have a great season," he explained. "A bad week on the PTR is preferable to three months of recovery from a poorly received surprise update."
He's aiming to expand PTR access to consoles, currently limited to PC due to certification complexities. Xbox's support is proving invaluable in this endeavor.
Diablo 4's presence on Game Pass is also a significant advantage, removing barriers to entry and attracting a wider player base. Fergusson compared this to releasing Diablo 4 on Steam—both strategies aim to maximize reach.
"A premium live service like Diablo faces different growth challenges than a free-to-play title like Diablo Immortal. Game Pass eliminates the barrier of purchasing the game, constantly introducing new players."
All Hours Diablo
Our conversation concluded with a discussion of Fergusson's personal gaming habits. He listed 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 alone, excluding work). He highlighted his enjoyment of both the Companion Druid and Dance of Knives Rogue builds, emphasizing his enduring love for the Diablo franchise.
"It's the habit," he explained. "I get distracted by other games, but I always come back to Diablo. I do my dailies in NHL, play Destiny 2 with my brother, and then... Diablo. It's my favorite game."
