TTRPG Game Master skills for Claude. An apprentice that helps GMs run tabletop role-playing games -- from a first spark of an idea through content generation, live play, and campaign management.
/plugin marketplace add AntTheLimey/gm-apprentice
/plugin install gm-apprentice
/reload-plugins- Open Claude Desktop and switch to the Cowork tab
- Click Customize
- Under Personal plugins, click + (Add plugin)
- Select Create plugin > Add marketplace
- Enter:
https://github.com/AntTheLimey/gm-apprentice - Once synced, click Install on the gm-apprentice plugin
If your plan doesn't include plugin support, upload skills individually:
- Download the
.zipfiles you want from the latest release - In Claude Desktop, go to Chat > Skills
- Click + and upload each zip file
- Install the Claude Code extension (Cursor: the Claude Code extension for Cursor)
- Open the Claude Code prompt and type
/plugins - Go to the Discover tab, add the marketplace
AntTheLimey/gm-apprentice, and click Install
JetBrains IDEs (IntelliJ, PyCharm, WebStorm, etc.) have no plugin management UI yet — install via the CLI method above.
You talk to Claude normally; skills activate automatically from what you ask. Say "build me an NPC" and Claude reaches for ttrpg-expert; say "help me start a new campaign" and it reaches for the-midwife.
| Skill | Description | Obsidian |
|---|---|---|
| the-midwife | Guided adventure creation through creative conversation — develops a campaign, one-shot, or arc from a vague idea or nothing at all, then writes an adventure brief and scaffolds the vault for Session 0. | Optional |
| ttrpg-expert | Rules engine, content generation, canon management, continuity checking, session planning, encounter design, scenario writing. | Optional |
| campaign-organizer | Campaign architect — classifies, structures, cross-references, and interlinks campaign content with knowledge-graph metadata. | Recommended |
| campaign-qa | Quality auditing — canon audit, timeline validation, name similarity, clue redundancy, graph-health checks. | Recommended |
| session-prep | Between-session preparation — reconciles last session, reviews PC arcs, scans threads, flags gaps, builds a prep package. | Recommended |
| session-play | At-the-table support — fast lookups, rules assist, on-the-fly NPC/location generation, note capture. Speed-optimised for live play. | Optional |
| session-wrapup | Post-session processing — narrative recaps, entity creation/updates, timeline entries, carry-forward. Accepts raw notes or GM-Assistant exports. | Recommended |
| vault-ingest | Ingest old campaign materials (notes, character sheets, images, transcripts) into a structured vault, interviewing the GM to recover what happened. | Recommended |
| publish-site | Publish your campaign vault as a static website on GitHub Pages or Cloudflare Pages. | Recommended |
ttrpg-expert is the advisor — pure reference, zero dependencies on other skills. Everything else is a doer with a specific job:
| Category | Skill | Boundary |
|---|---|---|
| Advisor | ttrpg-expert | Rules, GM craft, RPG techniques. No vault writes; other skills read its references but it never calls them. |
| Adventure creation | the-midwife | Draws ideas out of the GM, shapes them into a playable starting point with an adventure brief and vault scaffold. |
| Campaign organization | campaign-organizer | Owns the vault schema and file layout. Structures and links — doesn't generate narrative content. |
| Quality assurance | campaign-qa | Finds problems and fixes each on your say. Hands off to campaign-organizer (structure) or ttrpg-expert (content) when a fix needs them. |
| Session lifecycle | session-prep → play → wrapup | Prep bridges wrap-up to the next session; play is at-the-table; wrap-up turns raw notes into canon and feeds prep. |
| Content ingestion | vault-ingest | Classifies old material, interviews the GM, hands off to campaign-organizer and session-wrapup. |
| Content publication | publish-site | Reads the vault, generates HTML. No vault writes. |
From a spark of an idea to your first session. The full walkthrough with example prompts is in the Quickstart Guide.
- Conceive it — the-midwife. "I want to run a Call of Cthulhu game in 1920s Manhattan — help me build it." The midwife draws the concept out through conversation and, when you're happy, writes an adventure brief and scaffolds your vault. Tell it your system up front; it won't assume.
- Build the world — ttrpg-expert. "Make the main antagonist — a wealthy industrialist funding occult research." Generate NPCs, locations, and factions as you need them; each starts as DRAFT until you accept it into canon.
- Prep session 1 — session-prep. "Help me prep session 1." It plans scenes as options you choose from and flags the gaps still to fill.
- Run it — session-play. Fast lookups and note capture at the table.
- Process it — session-wrapup. Hand over your notes; it writes the recap, creates entities for new NPCs, and tells you what carries forward. Next time, session-prep reconciles anything skipped.
As the vault grows, reach for campaign-organizer (file and link accumulated content), campaign-qa (periodic health checks), and vault-ingest (import old material). The midwife scaffolds the starting vault, so none of these are needed on day one.
- Call of Cthulhu 7th Edition (CoC 7e) — includes the Regency Cthulhu variant
- GURPS 4th Edition — 7 archetype chargen kits, 24 topic-based reference files, and curated Basic Set content
- Forged in the Dark (Blades in the Dark) — 14 SRD reference files covering mechanics, playbooks, crew types, cohorts, and GM procedures
- D&D 5th Edition (2024 Revision)
- Pathfinder 2nd Edition (Remaster) — classes, ancestries, spells by rank, curated Monster Core statblocks, feats, and GM math tables, all from ORC-licensed sources
Tell Claude which system you're running when you start — it won't assume.
- Quickstart Guide — your first campaign, step by step
- Campaign Lifecycle — how the skills work together across the life of a campaign
- Per-skill guides: ttrpg-expert · the-midwife · campaign-organizer · campaign-qa · session-prep · session-play · session-wrapup · vault-ingest · publish-site
- Site settings — every setting for a campaign's site, what it does and its default
- Personal reference files — add your own rulebook content for deeper system support
- gm-apprentice-publish — reference for the publish tool that ships with the plugin
A campaign vault is a plain folder of markdown files — no servers, plugins, or app dependencies. Open it in Obsidian whenever you want the graph view, backlinks, and a vault UI at the table; nothing requires it.
The bundled utilities under skills/shared/scripts/ give the skills
ranked search, link-graph audits, schema validation, and more — Python
3.10 or later, standard library only, no packages to install. Python 3 is
a required dependency of this plugin. The skills invoke it as python3
from Claude Code's Bash tool, which on Windows is Git Bash: macOS and
most Linux ship python3 already; on Windows, install Python from the
Microsoft Store, whose python3 alias Git Bash finds on PATH (the
python.org installer provides only python and py).
A site is optional, and the vault's player_site.publish setting
says whether there is one. Publishing needs
Node 22 or later, and for a vault whose site is on, the checks that ask
which lines of a note would publish (vault_check.py gm-leak,
pc-body and wrapup) ask that site's publish tool rather than keep a
copy of its rules. With the site off nothing is built and nothing is
checked for leaks, and the vault needs only Python.
Original content (skills and markdown) is licensed under CC-BY-SA 4.0. Code (scripts, hooks, and executable files) is licensed under MIT.
This project includes material from open game content licensed under CC-BY 4.0 (D&D SRD 5.2), CC-BY 3.0 (Blades in the Dark SRD), and the ORC License (Basic Roleplaying and Pathfinder Second Edition Remaster).
GURPS is a trademark of Steve Jackson Games, and its rules and art are copyrighted by Steve Jackson Games. All rights are reserved by Steve Jackson Games. This game aid is the original creation of AntTheLimey and is released for free distribution, and not for resale, under the permissions granted in the Steve Jackson Games Online Policy.
See ATTRIBUTION.md for full credits and licensing details.