Posted November 11, 2025 by wonderxworlds
Hi everyone,
I've just uploaded "Callsign: Gemini," the story of Cadet Starla Mesa, an ace mecha pilot who uncovers a conspiracy that shatters her reality—and then fights to reveal the truth to humanity!
“Callsign: Gemini” is also an experiment: a playtest of the WONDER × WORLDS solo rules using a “Solo+AI” format. In this format, I enter prompts as the solo player into a large language model (LLM, in this case Gemini 2.5 Pro), react to (and correct) the AI’s suggestions, have my player character (PC) take actions and make interpretations of various Move and Oracle results using the WONDER × WORLDS rules and tools for solo play—and then iterate with the AI as the story moves forward.
Crucially, this is very different from an “AI as GM” approach, which often strips players of agency and creative control. In my game, the LLM was a collaborator (a co-screenwriter) but not the game “master.” Throughout the game, I drive the story and my character’s development. I come up with key story developments in many instances while partnering with the AI in others. I determine how the rules and mechanics are used. Throughout, I retain agency and frequently override the AI’s responses (and mistakes). This is not the only or necessarily best way to play WONDER × WORLDS solo—the AI is doing some of the work, after all, and it makes mistakes. But it was a very fun solo/collaborative exercise—and it really showcases the game’s potential to tell exciting stories!
The uploaded document is a lightly edited transcript of the chat log between me (“Me”) and the LLM Gemini 2.5 Pro (“ChatBot”). I left most of the LLM’s hallucinations and errors in place to show both the limitations of using AI and how it is possible to correct and nudge the AI back on track. I divided the narrative into acts (to make the narrative easier to follow) and retitled some scenes for clarity—but all dice rolls, mechanical decisions, and story beats remain exactly as played.
In terms of process, I began by uploading the WONDER × WORLDS rulebook. I then uploaded background on the setting, which takes inspiration from giant robot anime such as Gundam, Macross, and Neon Genesis Evangelion. I then provided information about my PC (Starla Mesa) and my idea for an instigating scene to kick off Starla’s Quest. After that, the story of Starla (callsign “Gemini”) and her mech Janus achieved lift off!