Any world you can imagine. Rules made to fit it.

The AI tells the story. WyrdTale makes the world real.

A game engine built for an AI game master. Describe a setting and it builds the rules that setting needs, then runs them: real dice, real consequences, and a world that is still there next session.

Connect it to the AI you already use

Works with Claude or ChatGPT. Free to connect during open beta. Setup in three steps.

One engine. No two worlds alike.

Each of these began as a conversation. Space Cowboy is the most complete and the one to start in. The other two are playable works in progress, here for inspiration. Best of all, make your own.

A hopeful frontier where humanity are the reckless newcomers among ancient civilizations.

Who you can be
Combatant, Pilot, Technician, Scholar, Operative, Envoy, Medic, Civilian, Anomaly
Class resources
A Pilot's Tempo builds with every maneuver. A Combatant's Grit rises each time they take a hit.
How deadly
Grounded. Ships fight too, and a ship's cannon is overkill on a person.
Status
The most complete starter world. New players should begin here.

The rules serve your world

WyrdTale plays like having an AI dungeon master, but it isn't D&D 5e with a new coat of paint. There is no fixed ruleset bolted onto every setting. You talk about the world you want, and the engine builds mechanics around it.

You set how deadly it is

One dial per world, from lethal, where a sharp blade threatens anyone, to epic, where heroes shrug off what would level a town. Every hit scales to match.

Power works your way

Rage, concentration, mana, stamina, nerve, or nothing at all. Each kind of character can carry its own resource: one that builds as they take hits, drains as they act, or returns with rest, whatever your fiction calls for.

Only the parts you need

Vehicles that fight. Weather and calendars that belong to a place. Money measured against a week's wage. Factions, secrets, slow-burning tensions. Use what your world calls for.

Not a spreadsheet game

AI narrators are bad with spreadsheets, so WyrdTale never hands them one. Every system was handcrafted by a professional AI engineer to suit a language-model game master: the engine does the arithmetic and gives the AI words it can tell a story with.

The dice are real

Whatever world you build, the engine rolls for it and the AI has to narrate the result it was handed. A good plan can still fail, and a failure moves the story. Both of these come from real sessions.

Example of play: one combat round

The player

“I lunge to the right, covering the two steps in one stride, then begin firing off rounds in the direction of the man in front of me, trying to hit him, while running for cover behind the ship.”

The engine

INITIATIVE ORDER
  1. Denn: 18 (d20=16, DEX +2)
  2. Jett Burrow: 16 (d20=13, DEX +3)
  3. Roby: 11 (d20=9, DEX +2)

Denn attacked Jett Burrow with DEX (CRITICAL MISS! 3 vs AC 16)

Jett Burrow used Ben's Sidearm (using DEX)
  • Roby was hit (22 vs AC 12) [decisive] took 9 energy damage (1/10 HP)
  resource changes: Jett Burrow Resonance 2 → 3

── Combat · Round 1 · The Barn · Night ──
Allies:
  Jett Burrow — Healthy · Resonance 3/10 ← acting
Enemies:
  Denn — Healthy
  Roby — Critical

What the player reads

You feel it more than see it: the flat crack, a spit of splinters where the shot bites the doorframe a full body-width from where you'd been … Your read was true. He shot the space you'd already left.

It's nothing like the footage. There's no music. There's just the buck of it in your two hands — steady, steady, the way he drilled you, hands that don't inherit the body's panic — and the scarred man in the doorway going from a shape with his palms up to a shape folding around itself.

From a real Space Cowboy session.

Example of play: the plan that didn't survive

The engine

Aldric of Colmere rolled DEX check: CRITICAL FAILURE! (5 vs DC 13)
  d20 1 + DEX 2 + 2 (Sound melee doctrine — rope-line back-cover, picking fights, staying unengaged in the opening press)

Aldric of Colmere took 3 bludgeoning damage, (9/12 HP)

What the player reads

The trumpet sounds, eighty men roar, and your beautiful doctrine survives exactly forty heartbeats.

From a real session in Vaskoria, a world a player built. A good plan earned a +2. The die came up 1.

Your world remembers, and keeps secrets

Everyone you meet is a saved record with their own motives, and the GM re-reads the save before each session. What you haven't discovered stays hidden from you, on purpose.

Session 3

You show the binding mark to the blacksmith. He flinches, hard, and turns back to his anvil. Won't explain. Changes the subject twice. Offers you a discount on a sword you didn't ask about.

Session 12

You return to Garrett's forge. For the first time, he closes the shop door. He remembers you. He reaches under the anvil and slides a tarnished key across the workbench.

What the GM knew all along

Garrett is a former acolyte who fled the Unbound Circle when he saw what the bindings really held. He still has the key to the inner sanctum, and they think he's dead.

Bring everything your AI can do

WyrdTale runs inside the AI you already use, so the rest of its abilities come along. Ask Claude to draw a terrain map of the region you just explored. Ask ChatGPT to paint your character, or the tavern you are standing in.

The engine keeps the world true. Your AI can show it to you however it likes.

See it in play

A walkthrough of how the engine works, followed by a real campaign running on it.

Watch on YouTube

Connect and play, free

Free to connect during open beta, with no WyrdTale credits or metered turns. Bring your own AI and play as long as you like. Join the Discord or r/WyrdTale on Reddit if you want a hand.

  1. Connect

    Add WyrdTale to Claude or ChatGPT as a custom connector.

    1. Open claude.ai or Claude Desktop
    2. Go to Settings → Connectors
    3. Click Add custom connector and enter https://wyrdtale.com/mcp
    4. Start a conversation and enable the connector
    Alternative: Claude Desktop via mcp-remote

    Add this to your Claude Desktop config file (requires Node.js):

    {
      "mcpServers": {
        "wyrdtale": {
          "command": "npx",
          "args": ["mcp-remote", "https://wyrdtale.com/mcp"]
        }
      }
    }
    Play with any MCP client

    Any client supporting remote MCP servers can connect to https://wyrdtale.com/mcp

    Recommended models: Claude Opus 5.5 is the best role-play model right now, and GPT-6.1 Sol is second. Any capable MCP agent can connect.

  2. Add the GM Guide to Project Knowledge

    WyrdTale's Game Master runs from an operating guide. Pin it in a Claude or ChatGPT Project so your AI keeps it loaded across long sessions, even after hours of play fill the context window.

    1. Download the guide below (current version v53).
    2. In Claude or ChatGPT, open or create a Project.
    3. Add the downloaded guide to the Project's knowledge or files.

    Download the guide (v53)

    At the start of play the GM looks for the line WYRDTALE GUIDE v53 in your Project. If it ever reports the guide is missing or out of date, download it again here and replace the guide in your Project.

    Playing with two? Two people can share one screen, one chat, and one story. Add the co-op GM guide to the same Project alongside the main guide—it teaches your GM to run a two-player table.

  3. Say the first line

    Make your own world. In that Project, enable WyrdTale and say “Start a new game.” Talk about the setting you want, and nothing is committed without your approval.

    Or start in Space Cowboy. It is the most complete starter world. Say “Play Space Cowboy.” Keep its hero, take over anyone else, or reshape it.