At the DICE Summit 2025, Rod Fergusson, the general manager of the Diablo series, kicked off his talk by addressing one of the franchise's most notable setbacks: Error 37. This infamous error code emerged during the launch of Diablo 3, preventing players from logging in due to an overwhelming influx of simultaneous users. The widespread issue led to significant backlash against Blizzard, even spawning memes across the gaming community. Although Blizzard eventually resolved the problem and Diablo 3 went on to become a success, the experience has left a lasting impact on the team's approach to game launches and ongoing support.

With Diablo 4 evolving into a more complex live service model, featuring regular updates, continuous seasons, and planned expansions, Fergusson and his team are committed to preventing any repeat of Error 37. The stakes are higher than ever, as maintaining player engagement between major content drops is crucial for the game's longevity as a live service juggernaut.

Diablo, Immortal

In a follow-up discussion at the DICE Summit 2025 in Las Vegas, I had the chance to delve deeper with Fergusson into his vision for Diablo 4. His talk, titled "Evolving Sanctuary: Building a Resilient Live-Service Game in Diablo IV," outlined four key strategies for ensuring the game's resilience: effective scaling, consistent content delivery, flexible design philosophy, and proactive player communication.

Fergusson's emphasis on maintaining a steady player base through regular engagement marks a significant shift from the traditional model of the Diablo series. Unlike previous entries that relied on periodic expansions and updates, Diablo 4 is designed to embrace the live service model, ensuring ongoing player investment through a meticulously planned content roadmap and forward-thinking seasonal updates.

When asked about the long-term vision for Diablo 4, Fergusson hinted at a prolonged lifespan for the game but stopped short of calling it eternal. He referenced Destiny's ambitious ten-year plan and noted that while Diablo 4 might not follow that exact model, the team aims to respect players' time by offering a clear vision of the game's future.

Fergusson also discussed the challenges faced in maintaining the game's update schedule. Initially, the team had planned for annual expansions, but the second expansion, Vessel of Hatred, was delayed until 2026 due to the need to prioritize immediate updates and the first season's launch. Fergusson expressed reluctance to commit to specific timelines for future expansions, citing the importance of internal certainty before making public announcements.

Ruining the Surprise...on Purpose

Transparency is a cornerstone of Fergusson's strategy for Diablo 4. He highlighted the use of content roadmaps and the Public Test Realm (PTR) as vital tools for player engagement and feedback. Initially, the team was hesitant to spoil surprises, but Fergusson now believes that it's better to "ruin the surprise for 10,000 people so that millions of people have a great season." This approach allows the team to test and refine upcoming content, reducing the risk of major issues upon release.

Fergusson also shared plans to expand the PTR to console players, acknowledging the current limitations due to certification challenges. With the support of parent company Xbox, Blizzard is actively working on this expansion. He emphasized the strategic importance of platforms like Xbox Game Pass and Steam, which help lower barriers to entry and attract a broader player base, contrasting with the model of Diablo Immortal, a free-to-play live service game.

All Hours Diablo

In our closing conversation, I asked Fergusson about his current gaming habits to gain insight into his inspirations. He dismissed comparisons between Diablo 4 and Path of Exile 2, stating that they are "very different games." However, he is mindful of players who enjoy both titles and aims to avoid overlapping seasonal releases to allow players to enjoy both games without having to choose.

Fergusson revealed his top three games of 2024 by playtime: NHL 24, Destiny 2, and, unsurprisingly, Diablo 4. With over 650 hours logged on his personal account, he's deeply invested in the game, currently enjoying the Companion Druid and Dance of Knives Rogue builds. His passion for Diablo is evident, as he balances his professional responsibilities with his personal enjoyment of the game.