Show HN: I built an AI that turns any book into a text adventure game

This is cool! I've recently been working on a similar project as a way to "walk around" in my own writing, understand my characters more, etc. I like the three-choice mechanism, with free-text, which I also use.

I do feel like, as a reader, I would have to be really desperate to "live within" the world of a novel to use it as a narrative experience, but I understand that there is definitely a demand / desire for that sort of thing, so I hope it hits for people.

I input my own novel's title to see if I could do the same. That novel hasn't yet - I believe - been libgenned for "training" by the major LLM providers, though its metadata / marketing materials exists in the knowledge (released fairly recently, announced longer ago). It resulted in a very funny narrative beginning in which the main character was the novelist Patricia Highsmith, which I think was a name used in the marketing materials as a reference point. A very surreal experience.

This is going to be a niche use case, obviously, but what might be more common is for users desiring to enter custom narratives (though I know some services provide this basic function already).

A much more important bug to flag: where the API fails, the "Try Again" button doesn't seem to resend my prompt, but literally the prompt "Try Again". Here's the text, as I couldn't see a way to link to the story (in which I was trying to see how good the 'guardrails' are for keeping the story in-universe and reasonable - props for it not allowing me to teleport to planets outside of the canonical universe).

https://pastebin.com/tjT2zR4R

It would probably just switch perspective with each chapter. If the AI has any real grasp of literary devices something metafictional like City of Glass could be interesting but an earlier/less complex example of metafiction like Marshlands might work better? If my memory serves I think the metafictional aspects of Marshlands could translate into this even if the AI completely misses the metafiction. Might play with this when I have more time.

Well, he is a wizard

I went to some lengths to ground the action in my game: https://ianbicking.org/blog/2025/07/intra-llm-text-adventure

That said, I think there's a lot of prompting techniques that can help here. (Actually the Guided Thinking section is an example of prompt-only techniques: https://ianbicking.org/blog/2025/07/intra-llm-text-adventure...)

You must at least do some pre- and post-processing to have the LLM consume and generate text that isn't part of the main user interface. But given that you can put in guidance that can increase the small-scale surprise of the interaction. For instance I'll have the LLM write out some of the objective environment at the moment before it considers a decision, so that it doesn't essentially retcon the setup for a plot direction it intends to take.

For the larger arc you'll need something like memory to pull the whole thing together. That include repetition over time. You can ask the LLM not to repeat itself, and it can do that, but only if it understands what it's done. And to some degree it needs to understand what it's _doing_: the LLM like the player is still generating short turns, and so if it wants to create surprise that is revealed over multiple turns then it needs space to plan ahead.

I wouldn't be surprised if, being Bilbo, Gandalf would troll me like that, just to prove a point he's trying to make.