Calibre 9.15, a free software for managing and organizing ebooks, has introduced a new interactive feature called Create your own adventure, an AI-driven storytelling game where users build their own universe and choose actions while an AI model advances the narrative. The feature, which was initially intended to test the compatibility of various AI engines with the software, became popular enough to be turned into a full-fledged feature, according to Kovid Goyal, the creator and maintainer of Calibre. However, the feature is not immediately accessible; users must manually add it to the main toolbar in the Preferences menu. The feature allows users to select from eleven predefined atmospheres, such as fantasy, space opera, cyberpunk, western, or gothic horror, or create their own universe. The AI model then generates the setting, characters, and game mechanics. The gameplay involves writing an action, receiving a continuation, and repeating the process. Unlike traditional multiple-choice formats, players freely formulate their actions without being restricted to A, B, or C choices. The story generated can be exported in EPUB format, complete with a cover and chapters, and stored in the Calibre library. However, Calibre does not use its own generative model; instead, it serves as an interface for user-configured or locally installed AI models. During testing, Korben used Ollama with a Qwen model on a Mac M4, which required about a minute per 450 words. The language of the response was influenced by the instructions given to the model; a French-described universe generated a response in English unless explicitly requested otherwise. The AI-driven narrative creation is part of a broader integration of AI features in Calibre, which began with the Ask AI feature in version 8.11.1 in September 2025. Subsequent updates expanded these capabilities, including discussion around works, reading recommendations, and support for local execution with LM Studio. In December 2025, some users protested against the inclusion of AI features in a software dedicated to books, with some authors expressing concerns about the use of works for AI training. Goyal maintained the features but included an option to hide their presence in the interface, a feature still present in version 9.15. The latest update marks a shift in AI's role within Calibre, moving from commentary and recommendations to active narrative creation, which can then be stored within the software's library. Users can choose to engage with this new feature or continue managing their EPUBs as before.