How Should Hit Sequels Be Made? Subnautica 2 Developers Reveal the Fear of "Sequelitis" and the "Rule of Thirds" [gamescom]

Summary

At gamescomdev 2026, a keynote speech was held on the popular survival-craft game Subnautica 2, set on an unknown ocean planet. The talk centered on the fear of "sequelitis" that major hit sequels face, and the clear design methodology the development team derived: the "Rule of Thirds." Sequelitis refers to the phenomenon where many successful games lose their original charm in their sequels due to over-catering to player expectations or blindly adding new features. To preserve the essence of the original while delivering fresh appeal, the Subnautica 2 team proposed a design principle that new elements should account for about one-third of the entire experience. This rule means retaining the familiar core mechanics and atmosphere, while only one-third of the systems are renovated or supplemented, striking a balance between veteran players' comfort and newcomers' surprise. The speech further explored how the team analyzed feedback from the first game, selected the parts truly worth evolving, and avoided losing control during development due to over-expansion. The presentation deeply resonated with attending developers and offered a new framework for sequel design. For players, how Subnautica 2 puts this rule into practice is highly anticipated, and it also provides a practical reference for other game teams working on sequels.