At the DICE Summit 2025, Rod Fergusson, the general manager of the Diablo series, kicked off his talk by addressing not the triumphs but a significant setback: the infamous Error 37. This error, which emerged during the launch of Diablo 3, notoriously blocked players from accessing the game due to an overwhelming influx of simultaneous logins. The issue drew heavy criticism towards Blizzard and even turned into a meme. Despite the initial hiccup, Blizzard managed to resolve it, and Diablo 3 eventually became a success story. However, the memory of Error 37 lingers as a lesson learned, especially as Diablo evolves into a more sophisticated live service model with regular updates, seasons, and expansions. Diablo 4, more than its predecessors, has fully embraced this live service approach, making it crucial to avoid similar launch failures to ensure its longevity as a premier live service game.

Diablo, Immortal

Following his keynote, “Evolving Sanctuary: Building a Resilient Live-Service Game in Diablo IV,” at the DICE Summit 2025 in Las Vegas, I had the opportunity to discuss with Fergusson the future of Diablo 4. On stage, he outlined four essential strategies for maintaining the game's resilience: scaling the game effectively, ensuring a steady flow of content, not being overly rigid with design purity, and keeping the player base informed about future updates, even at the cost of surprises.

Fergusson emphasized the importance of keeping players engaged over the long term, a shift from the traditional model of numbered sequels every few years to a continuous live service model. This approach is evident in the detailed content roadmaps and season planning he discussed, which contrast sharply with the update strategies of past Diablo games.

When asked about the longevity of Diablo 4—whether it's meant to be eternal or immortal—Fergusson expressed a desire for the game to last for years, though he hesitated to commit to the term "eternal." He drew a comparison to Destiny, which initially planned for a ten-year lifespan but adjusted its approach. Fergusson stressed the importance of respecting players' time investment and providing clear visibility into the game's future.

He also highlighted the significant time gaps between previous Diablo releases, noting that neither Diablo 2 nor Diablo 3 had the aggressive update schedule planned for Diablo 4. However, with Fergusson at the helm since 2020, after his tenure with the Gears franchise, he's keen on planning ahead but not too far in advance. This cautious approach was evident when he announced that Diablo 4's second expansion, Vessel of Hatred, would not arrive until 2026, a delay from the initially planned one-year cycle due to the need to prioritize immediate updates to the live game.

Ruining the Surprise...on Purpose

Fergusson's talk also touched on the importance of transparency and the use of tools like the Public Test Realm (PTR) and content roadmaps. Initially, the team was hesitant about spoiling surprises for players, but they've come to realize that it's better to "ruin the surprise" for a smaller group to ensure a better experience for the majority. The PTR, currently available only on PC via Battle.net, allows players to test upcoming patches before they go live, helping to refine the game and avoid potential issues. Fergusson expressed interest in extending the PTR to console players, a move supported by Blizzard's parent company, Xbox.

The inclusion of Diablo 4 on Xbox Game Pass is another strategic move to lower barriers to entry and attract a broader player base. Fergusson compared this approach to the decision to release Diablo 4 on Steam alongside Battle.net, emphasizing the importance of reaching as many players as possible. He contrasted this with the free-to-play model of Diablo Immortal, noting the different growth opportunities each model presents.

All Hours Diablo

As our conversation drew to a close, I inquired about Fergusson's recent gaming habits, curious about any influences on Diablo 4. He dismissed comparisons between Diablo 4 and Path of Exile 2, noting their distinct differences. However, he acknowledged the feedback from players who enjoy both games, particularly their requests for non-overlapping season schedules to allow for more flexible gaming.

Fergusson shared his top three games of 2024 by playtime: NHL 24 in third place, Destiny 2 in second, and unsurprisingly, Diablo 4 in first. With 650 hours of playtime on his home account alone, Fergusson's passion for Diablo is clear. He's currently enjoying playing as a Companion Druid and has recently started a Dance of Knives Rogue. His love for the game, which prompted him to join the Diablo team five years ago, continues to drive his dedication both at work and at home.