Huang, Runsheng "Anson"Martin, Lara J.Callison-Burch, Chris2025-01-222025-01-222024-12-17https://doi.org/10.48550/arXiv.2412.10582http://hdl.handle.net/11603/37395WHAT-IF -- Writing a Hero's Alternate Timeline through Interactive Fiction -- is a system that uses zero-shot meta-prompting to create branching narratives from a prewritten story. Played as an interactive fiction (IF) game, WHAT-IF lets the player choose between decisions that the large language model (LLM) GPT-4 generates as possible branches in the story. Starting with an existing linear plot as input, a branch is created at each key decision taken by the main character. By meta-prompting the LLM to consider the major plot points from the story, the system produces coherent and well-structured alternate storylines. WHAT-IF stores the branching plot tree in a graph which helps it to both keep track of the story for prompting and maintain the structure for the final IF system. A video demo of our system can be found here: https://youtu.be/8vBqjqtupcc.21 pagesen-USAttribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/Computer Science - Computation and LanguageText