TL;DR: A Reddit user shared a setup for running D&D 5e (2014) in a ChatGPT Project. Put a GM prompt in the project instructions, upload your sourcebooks as Project Sources, and have the AI hand you session notes as PDFs that you feed back in.
The Setup, Step by Step
The poster (u/ThirdEntityBeing) built this for people who already know what a real D&D 5e table feels like. The goal is to make the AI behave the way a campaign sourcebook expects a DM to behave.
Here is the workflow:
- Paste the GM Prompt into the project instructions in the ChatGPT app.
- Upload your campaign sourcebooks, rulebooks and homebrew as Project Sources.
- At the start, tell the AI to read the Campaign Structuring and Rulebook Guide once.
- Tell it to keep checking the campaign source material throughout every session.
- For important or recurring characters, tell it to use the Fulfilled Character Generation Engine.
The GM Prompt itself isn’t pasted in the post. What you get is the workflow and the example commands around it.
A practical tip if you try this: give your uploaded files clear, boring names, like “Campaign Sourcebook”, “Homebrew Rules” and “Session Notes 03”. When the AI has to decide which file to check, plain names make that easier, and it makes your own life easier when you need to swap one out later.
The Session-Notes Loop
This is the part I’d steal first. Chat memory drifts over a long campaign, so the poster moves the memory into files.
The session ends only when the player asks for it. At that point the AI should produce:
- A GM-facing version of the session notes
- A player-facing version of the session notes
- An NPC and monster registry with stats for every character with a true or probable combat status
All of it comes back as PDFs. You then add the updated notes back into the project, so the next session starts from what actually happened.
Two small habits keep this loop clean. Put the session number in each filename, and remove the older registry when you upload the new one, so the AI isn’t choosing between two versions of the same goblin. At the start of the next session, ask for a short recap of the last one. If the recap is wrong, you catch the problem before it ripples through the story.
Why the Prompt Matters for Dense Campaigns
The poster pairs the prompt with a campaign sourcebook they directed the creation of, the Charter of Nine Roads. They say the campaign is very detailed, and without the prompt translating it into plain D&D terms you can get lost. In their words, having played through it, the prompt makes it much easier to know what is supposed to happen next without hand-holding.
That’s one person’s report, so treat it as a promising lead rather than a benchmark. If your own campaign is dense, the same idea should carry over: the longer the sourcebook, the more a translation layer helps.
What the Opening Scene Looked Like
The poster tested it with a level 3 Rogue Swashbuckler entering a tavern. The AI did a few things worth copying:
- It opened with a clear “Where You Are” and “Why You’re Here” before any action.
- It laid out the room’s size and exits, and named the NPCs worth talking to.
- It listed the character’s relevant class features, and said it would not invent ability scores or gear that hadn’t been supplied.
- It ended on a live moment, a tense argument, a courier getting up to leave, and the question “What do you do?”
The poster also noticed the AI will crossplay between games set in the same setting.
Notice the refusal to invent ability scores or gear. That is a good habit to demand from any AI game master. If you want a specific build, paste your character sheet into the project first so the AI has real numbers to work with.
Use Cases
- Solo D&D sessions when your group can’t meet
- Running a published or homebrew campaign with the sourcebook always on hand
- Keeping a long campaign consistent through notes and an NPC registry
- Testing a character build before you bring it to a real table
Prompt of the Day
This is the poster’s test prompt. Swap in your own character and setting:
My level 3 character, a Rogue Swashbuckler named Móthrün Víros, enters a tavern in the Nine Roads campaign setting. Describe and engineer the scene as part of helping me, the player, understand where I’m at and what I know, what I can do, who I can recruit, and why I’m here.
The last clause is the useful one. Asking the AI to explain where you are, what you can do and who you can recruit gives you a scene you can act on right away.
Call to Action
Pick one campaign you already own, load it as a Project Source, and run a single tavern scene. At the end, ask for the GM and player notes as PDFs and add them back to the project. If you tweak the setup and get a better result, share the change in the original thread.
Play D&D5e (2014) with AI – this is explicitly for those familiar with a D&D5e experience offered by actual GMs. And reinforcement of roles that campaign sourcebooks expect from a DM.
by u/ThirdEntityBeing in ChatGPTPromptGenius