The setup I run at my own table.

Who sits at the table

Three of us play. I sit where the DM always sits: I frame the scenes, make the rulings, and decide what the world does next. My wife plays Naia, her sorcerer, and nobody else touches that character. The AI plays the other two heroes, a barbarian and a bard, and has done for months. It also runs the monsters, voices the cast, and keeps the books.

The game is Ember, Foundry's official sandbox campaign, imported and prepped before anyone sits down. That choice matters more than any tool below it. Given nothing, a model invents, and inventions drift. Given a prepped campaign, it reads and runs what is on the page, and the world stays solid for months at a stretch.

• How to play D&D with AIThe method under this table: good prep, then hand the AI the running of it.
• Playing solo and duet with AIThe same rig with fewer humans: the AI runs the whole other side.

The stack

Every piece is ordinary on its own. The work happens in how they connect: Foundry holds the world, Familiar gives the assistant hands inside it, and the assistant I already subscribe to does the thinking. There is no separate AI bill at my table. The only extra keys are for speech: one that gives the cast voices, one that turns the microphone into text.

• Connect Claude, ChatGPT, or GeminiThe hookup, click by click, on the subscription you already have.
• Giving your NPCs a voiceNarrator and character voices, with your own provider key.
• MCP vs API: which to chooseWhy subscription beats per-token for a table that plays weekly.

What one evening looks like

The rhythm took a few sessions to find. What survived is a short pre-flight, one hard rule about text and audio, and a wrap-up that makes the next session cheap to start.

1. 1

   Pre-flight

   Open the world, start the assistant, and run one spoken test line. Two minutes, and it catches a dead mic or a silent voice before the cold open instead of during it.

2. 2

   Play

   I frame the scene and rule the edge cases. The AI narrates, plays its two heroes, and voices the NPCs. Every spoken line lands in the Foundry chat first, word for word, so the written record always matches what was heard.

3. 3

   Combat

   Initiative, monster turns, and the AI's heroes run through Familiar on real dice. My wife declares her own actions and rolls her own; the AI never decides anything for her character.

4. 4

   Wrap-up

   The AI writes the session log and one pickup paragraph: where the party stands, what is open, who is hurt. The next session starts by reading that back instead of by remembering.

• Combat & AI
• Voice & Image Generation
• Knowledge & Memory

• Running combat with AIWhat the engine enforces, so nobody has to trust a language model with dice.
• Staying consistent across sessionsWhy the wrap-up works: notes the AI can search beat a fading context window.

The files that keep it disciplined

None of the discipline above comes from the model's good nature. It comes from standing instructions the assistant reads before every session, split into small files with one job each. The split is the point: a model follows a few focused rules far better than one giant document, and small files let me fix one habit without retyping the rest.

The portable half is public. The rules pack is the table-manners layer, and it works pasted into any assistant. On top of it sit files only my table needs: how each character speaks, the combat house rules, what is canon in the world, and which secrets never appear on any page a player can see. Where they live depends on your assistant: a Claude Project, a Gem, or a rules folder for the coding-style tools.

my-game/
  rules/
    table-manners.md     the pack from /guides/dm-rules-pack
    roleplay.md          who speaks how, spoiler discipline
    combat.md            house rules, when to ask the table
    world.md             what is canon, what is off-limits
  session-runbook.md     pre-flight, the session loop, wrap-up
  logs/                  one file per session, newest is the pickup

• The rules I give my AI DMThe table-manners layer in full, ready to paste.
• Prepping a published adventure for AIWhere the campaign itself goes so the AI has pages to run from.
• Writing characters the AI can playThe anchor format behind the two heroes the AI plays here.

What broke before it worked

The echo was the worst one. A far-field mic hears everything, including the AI's own voice lines coming out of the speakers, so the transcript filled up with its lines attributed to me, and the speaker labels collapsed into one voice. The fix was embarrassingly small: send the AI's audio to headphones, or pause the mic during playback. If your transcript ever starts talking to itself, that is why.

Mid-session debugging nearly killed the pacing twice. When a tool call fails, the pull to fix it right there is strong, and it is wrong: two attempts, then narrate the result by hand and repair it after the session. The table came for the story. Nobody came to watch me read error messages.

And a frozen fight does not always thaw the way you left it. We pause combats between evenings, and the world can shift in the meantime. So the wrap-up records the exact combat state, and resuming starts with checking the tracker against the log before anyone rolls. Thirty seconds, and more than once it has caught a tracker that had drifted.

Build the same table

You can assemble this in an afternoon, and the order matters less than people fear. Install Familiar in Foundry, connect the assistant you already pay for, and paste in the rules pack. That is a playable table. Voices, the microphone, and the phone sheet are upgrades you add the week you want them, not prerequisites.

The one thing no tool installs is the campaign. Bring a published adventure you love, prep it into journals the AI can read, and it will run the long game with you at whatever size table your house happens to hold.

• How to add AI to Foundry VTTFrom an empty module list to a connected assistant.