Playing solo, with the AI on the other side.

What solo play with Familiar is

Solo roleplaying already has a deep toolkit, and most of it exists to generate a story when nobody is running the table. An oracle answers the yes-or-no questions you cannot answer for yourself. A GM emulator like Mythic GME adds a Chaos Factor that decides how hard the world pushes back. A purpose-built game like Ironsworn or Starforged turns the whole session into moves and oracle rolls. You ask, you roll, you read the result into fiction, and the surprise comes from the dice, because there is no author in the room.

Familiar is not an oracle, and it does not try to be one. It is built for the other way people play solo: you take a published adventure you own, the kind a professional designer wrote and playtested, and you run it in Foundry. The plot is already on the page. What you want is not a machine to invent a story, it is a machine to run the DM's side of the one you brought.

That is the forever DM's problem, stated plainly. You bought Foundry to run games for other people, you know these modules cold, and you would like to play one for a change. Familiar covers the side of the table you usually work. It rolls the monsters, voices the NPCs from your prep, enforces the 2024 5e rules, and remembers the campaign week to week. You take a character and play.

Familiar runs the published adventure you bring, it does not author a plot or replace a human DM with an inventing AI. If you want an engine that spins emergent story out of nothing, an oracle or Ironsworn does that better. Familiar runs the module you already have.

The two hats, and which one Familiar takes

Every solo player knows the two-hats problem. You are the player and the DM at the same time, often the narrator and the rules lawyer as well. You roll the goblins' attacks against your own character, look up how grappling works mid-turn, track who is poisoned and whose turn it is, and try to stay in the story while you do all of it. Combat is where it bites hardest. A fight you run against yourself tends to fall flat, because you already know what the monsters are going to do.

Familiar takes the DM's mechanical hat and leaves you the player's. When a fight starts it rolls initiative, plays the monsters, applies the conditions, and rolls every result on Foundry's own dice. You make your character's decisions and it runs everything on the other side. You stop refereeing your own fight, so even a module you know by heart still plays out differently at the tactical level: where the ogre moves, whether the save lands, what the dice do.

The rules live in code. A deterministic engine checks every move against the 5e rules before it lands, so the AI cannot fudge a roll in its own favour or forget that your character is prone. That matters more solo than anywhere, because there is nobody else at the table to catch the mistake. The Running combat with AI guide covers how the engine works, and why an AI that acts through Foundry's dice cannot cheat.

• Both hats: you roll the monsters against yourself, track the conditions, look up the rule, and narrate, all at once.
• One hat: you play your character, and Familiar rolls the monsters, tracks the conditions, and enforces the rules on the other side.

• Combat & AI
• Knowledge & Memory

How a solo session runs

Once the prep is in Foundry, an evening settles into a simple loop. You are the player throughout, and Familiar runs the rest.

1. 1

   Open where you left off

   Familiar reads last session's recap and the running plot summary from your journals, so it opens already oriented instead of asking you to catch it up. You pick up mid-scene.

2. 2

   Explore and talk

   You move your token, open a door, ask the innkeeper about the road ahead. The AI answers in his voice, from the character page you wrote, and fills the small edges itself: his mood tonight, a throwaway rumour. What is behind the unopened door stays hidden by Foundry's own fog of war and token vision, not by the model pretending it cannot see.

3. 3

   Fight

   Combat starts and Familiar takes the monsters. It rolls initiative, plays each enemy turn from the state of the battlefield, applies the damage and the conditions, and rolls all of it on Foundry's dice. You play your character's turn, it plays every turn on the other side. Bring an ally and it can take their turn too.

4. 4

   Wrap up

   Before you close down, ask it to summarise the session into a journal entry. That recap, plus a searchable record of what happened, is what it reads from next time. Two minutes of housekeeping now is what keeps a long solo campaign from drifting. The Staying consistent across sessions guide goes deeper.

• Voice & Image Generation
• Journals & Notes

Playing duet

Solo is one end of a spectrum. Bring one other person and you are playing duet, which is the sweet spot for a lot of tables. Neither of you has to be the DM. Familiar runs the world for both of you, the cast, the encounters, the rulings, so you both stay players and the story still moves.

This is close to how my table runs. My wife takes a character, and Familiar runs the adventure around her along with a couple of allies who travel with the party, taking their turns in a fight beside hers. A friendly NPC on your side runs on the same auto-pilot as the monsters, because the engine keys on who owns the token, not which side it is on.

You can hand it one of your own party's characters to play as well, through the same combat tools. It has run two of ours this way for months. That part is hands-on: you set it up per fight, rather than pointing at a sheet and walking away. The one-click companion mode, where you designate an ally once and it runs on its own initiative untouched, is on the roadmap, not in your hands today.

• Combat & AI

What you still bring, and what stays yours

Solo play with Familiar is not zero prep, and this audience knows to distrust anything that claims to be. You bring a published adventure, ideally one that comes Foundry-ready with the maps, walls, and lighting already built, and you structure it into your world once. Story beats become journal pages. The cast becomes sheets and statblocks. A one-page outline says what happens next. Then the AI reads from all of it, every session. The Prepping a published adventure for AI guide is the how.

Two smaller crafts sit alongside it. Writing an NPC the AI can play well takes only a few lines, who they are, what they know, what they want, and how they speak, and the Writing characters the AI can play guide covers it. Keeping a months-long campaign straight is the job of the Staying consistent across sessions guide. Solo leans on both harder than a full table does, because you are the only one holding the thread.

The plot stays yours, and so does the fact that you know it. Running a published module solo means you are also the person who read it, and no tool changes that. Familiar does not pretend to hide the story from you. You hold the GM screen, and an AI cannot truly keep a secret it can read. If staying surprised matters to you, the old solo discipline still beats any AI: don't read ahead, reveal each room only when your character steps into it, and let Foundry's fog and a dice roll decide what you see.

Balancing a fight for one character is your call too. Familiar runs the encounter as you prepared it. Scaling it down for a single PC, fewer bodies, less legendary resistance, a large fight handled off-screen through an allied NPC, is a prep decision you make before the session.

• Journals & Notes
• Characters & Items

The honest limits

A few things Familiar is not, said plainly, because a careful reader would rather hear them now than later. There is no one-click solo mode to switch on. You play solo the way this guide describes: bring a module, decide which tools the AI may touch, and start. A tidier solo preset may come later, but it would only package what already works, not add a new power.

It does not invent your plot, keep secrets, or surprise you the way a human DM does. It runs the story you bring, and hidden information lives in Foundry's fog of war, held by the map and the dice. That is the honest trade, and for running a published module it is the right one.

Its memory is good, not perfect. It reads from a searchable record you keep in Foundry, which beats trusting a chat window by a wide margin, but your notes do the remembering, and the AI reads them back.

And it is a paid tool that runs on an AI you supply. You bring the model or subscription you already pay for, and driven over the Model Context Protocol there is no extra per-token bill. Familiar itself is not free.

None of this is buried in fine print. It is the shape of an honest tool: it runs the mechanical DM's side of a real adventure, and leaves the story, the secrets, and the judgement calls to you.

Start playing

Install Familiar in Foundry, bring a published adventure you own, and connect the AI you already use. Take one character, hand the rest of the table over, and play the module you have always wanted to sit inside instead of run.

Questions about prepping for solo, playing duet, or setting up your first session are welcome in the Discord.