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 memorable internet meme. While *Diablo 3* ultimately triumphed, the experience underscored the importance of avoiding similar catastrophes, especially with *Diablo 4*'s ambitious live-service model featuring frequent updates, seasons, and expansions.
The potential for another Error 37-like incident is catastrophic, particularly given Blizzard's commitment to *Diablo 4*'s long-term viability as a true live-service juggernaut extending far beyond its major content releases.
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 marks a significant departure from previous numbered Diablo titles. While expansions and updates were common, *Diablo 4* represents a deeper commitment to the live-service model, prioritizing sustained engagement and significant, rapid changes over the release of new numbered installments every few years.
I asked Fergusson about *Diablo 4*'s longevity: is it aiming for immortality, or is there a planned transition to *Diablo 5*? His response suggested a long-term vision, but not necessarily an eternal one.
"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 path forward, recognizing the significant time investment they make. We want to demonstrate our respect for their time and commitment."
Fergusson highlighted the lengthy gaps between *Diablo 2* and *3*, and *3* and *4*, noting the absence of *Diablo 4*'s aggressive update schedule in those earlier iterations. He also emphasized his own influence, joining in 2020 after years leading the *Gears* franchise, bringing a different perspective to long-term planning.
His experience taught him the importance of cautious forecasting. His DICE Summit announcement of *Diablo 4*'s second expansion, delayed until 2026, exemplified this. The original yearly expansion plan was disrupted by 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. When asked if 18 months is the new standard for expansions, Fergusson remained noncommittal, stating:
"I learned my lesson about calling the shot too early. Giving players an 11-month heads-up is about as far as I'm willing to commit right now... We're still building and learning. We internally reach a point of certainty before making a public announcement."
Ruining the Surprise…on Purpose
Fergusson's cautious approach is understandable, given the team's commitment to unprecedented transparency. This includes a content roadmap (to be revealed in April) and the Public Test Realm (PTR), allowing players to test upcoming patches before live release. Fergusson initially hesitated about using the PTR and roadmaps, fearing it would spoil surprises, but changed his perspective:
"It's better to ruin the surprise for 10,000 people in the PTR so that millions of people have a great season. 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."
"We used to get really worked up about data mining and leaks," he added. "But we're reaching millions of players, so a few thousand seeing something early is insignificant in the grand scheme of things."
Currently, the PTR is limited to PC players via Battle.net due to console certification challenges. However, Fergusson confirmed that Blizzard is investing in expanding PTR access to consoles with the support of Xbox.
Fergusson also highlighted the positive impact of *Diablo 4*'s inclusion in Game Pass, emphasizing its role in expanding the player base. He compared this to the decision to release *Diablo 4* on Steam alongside Battle.net—both aimed at maximizing player reach.
"With a premium live service like *Diablo*, there's a barrier to entry, unlike free-to-play titles like *Diablo Immortal*. Game Pass removes that barrier, constantly introducing new players who discover the game and jump in."
All Hours Diablo
Finally, I inquired about Fergusson's gaming habits to gain insight into his inspirations. While acknowledging the comparisons between *Diablo 4* and *Path of Exile 2*, he emphasized their differences. He also noted player feedback regarding the scheduling of seasons across different games, aiming to avoid conflicts in future updates.
His top three games of 2024 by playtime were *NHL 24* (third), *Destiny 2* (second), and—unsurprisingly—*Diablo 4* (first), with over 650 hours logged on his personal account alone, excluding work. He currently plays a Companion Druid and recently created a Dance of Knives Rogue, highlighting his deep-seated love for the game.
"It's the habit," he explained. "I get distracted by other games, but I always come back to *Diablo 4*. It's my favorite game, and even working on it doesn't stop me from playing it for hours at home."
