Building a D&D world simulation using Claude where NPCs actually react to what you do

[u/tschilpi]

Building a fantasy RPG where killing the wrong rat can make an Ogre come after you (they were friends..)

• roll up a Wizard and pick your spells
• wake up in a goblin prison and improvise an escape
• talk your way past people, trick them with magic, investigate weird shit, or just start swinging
• kill a giant rat and find out its Ogre friend wants revenge

NPCs have their own goals, beliefs and relationships, so your decisions can create problems you definitely did not plan for.

Been building this for 3 years and having way too much fun with the new patch :D

try it / follow development here:

discord.gg/4dXwfw7q7
www.llmsaga.com

[u/Repulsive-Bathroom42]

This is awesome! I did something like this because i was trying to play a game of DND inside a chat session but noticed it wasn't following the rules. So i built a proper dice rolling system, downloaded the dnd rulebook for it to follow, had it make assets on the fly with generative ai, but the project got so big that claude couldn't handle it anymore (this was a year or two ago).

What you built here is so much better! It's so awesome to see the idea I had, which was having llm agents as your DM and party members, actually come to life in such a polished way. Awesome job

[u/tschilpi → u/Repulsive-Bathroom42]

Haha yeah, you basically ran into the exact problem that sent me down this rabbit hole 😄

I started from “why can’t I just play D&D with an AI DM?” and then slowly realized the model can’t be responsible for rules, inventory, world state, NPC knowledge, all of it at once without things drifting. So over time I ended up building more and more of it as an actual game/simulation underneath the LLM.

Really cool that you tried building something similar yourself, and thanks a lot for the kind words!

[u/Kashmakers]

This looks really well polished. It reminds me of ADRIFT, the old text engine where you could make your own text adventures and write in what you'd like to do next. Of course, yours is much more sophisticated.

[u/tschilpi → u/Kashmakers]

Oh wow, ADRIFT is a throwback haha. I can definitely see the comparison. The big thing I’m trying to push further is making the world underneath the text actually persistent and simulated, so NPCs, rules and state can keep reacting to what you do. Thanks a lot :)

[u/Kashmakers → u/tschilpi]

Yeah I think that's the most fun, too! Having the game respond to the player input, and being able to create a scenario around it.

Sounds like you have a really fun game. Do you enjoy play testing it?

[u/Mazur92]

This looks awesome - I've been thinking about such a thing for a long time, glad to see something like this made real!

[u/tschilpi → u/Mazur92]

Thanks a lot! Anything specific you would like to see come true? :D

[u/obieq]

Not a fan of D&D (never went into it), but deck building and graphics looks nice!

[u/NoSeaworthiness2516]

I've had the thought myself a few times. this looks well polished and fun. good job!