A campaign pack is a directory of Markdown files that gives the DM AI its ground truth for a campaign: the places, the people, the set-pieces, and the governance rules the table plays under. Everything the AI narrates is anchored to what's written here, so a session doesn't drift or re-improvise facts it already established.

This is the how-to. docs/design.md §6.4 is the authoritative spec; this document doesn't restate it, it walks you through writing one.

• Fastest start: copy campaign-packs/TEMPLATE/, rename the directory, and fill in the placeholders — every file there is commented.
• A complete real example: campaign-packs/sable-ravine/ — a three-session level 1–3 adventure, no chapters, ~14 files.

your-pack-slug/
  campaign.md          ← the only required file
  locations/*.md       ← one file per place
  npcs/*.md            ← one file per named NPC
  encounters/*.md      ← one file per set-piece (fight, parley, trap, choice)
  state.json           ← starting mutable state (optional; see below)

• The directory name is the pack slug: lowercase letters, digits, and hyphens only, no spaces. Conventionally it matches campaign.md's id.
• locations/, npcs/, and encounters/ are each optional and flat — no nested subdirectories. Files load in sorted filename order.
• Every file is YAML front matter between --- lines, followed by a Markdown body.

A pack is loaded by campaignpack.LoadPack (the same gate the admin panel's Bind Pack button and the pack-library installer run). It accepts a pack when:

• campaign.md exists and its front matter has a non-empty id.
• Every locations/, npcs/, and encounters/ file has a non-empty id in its front matter.
• All front matter parses as YAML.

Everything else is advisory. A pack with only a campaign.md is valid. A connections: entry pointing at a location that doesn't exist won't fail loading — but it will confuse the DM, so keep them honest.

voice: clipped, dry: and terse is invalid YAML — the second colon breaks it. Quote any value containing a colon or that starts with a special character:

voice: "clipped, dry: and terse"
title: "The Bridge at Kettle's Crossing: A Reckoning"

Master auto-repairs unquoted colons in generated packs as a belt-and-suspenders measure, but hand-authored packs get no such treatment — quote it yourself.

Front matter carries the pack's identity and governance. Body is the overview a DM reads once to understand the whole adventure: where it happens, what's wrong, who wants the party involved, and what resolving it looks like — written as a briefing of concrete facts, not atmospheric prose. Follow it with ## Hooks (how the party gets pulled in) and ## Running this pack (what a DM needs to know that isn't obvious from the individual files — the real problem behind the visible symptoms, how shared_knowledge bites, which threads are optional).

Front matter: id (required), connections (ids of other locations reachable from here — powers travel_to and the AI's sense of geography), optional chapter / side_quest.

Body: what the party perceives on arrival, what rewards a closer look (name the check and rough DC), and pointers to the NPCs and encounters found here. Describe what's true about the place; leave what happens to the encounter files.

Front matter: id (required), location (where they're normally found — a location id), stat_block_ref (a plain SRD creature or class type in quotes, e.g. "SRD Veteran" — never a named published monster; only matters if they fight), voice (a short phrase on how they talk), optional chapter / side_quest.

Body: personality and motivation — what they want, what they know (and under shared_knowledge: strict, what they don't), how they treat the party before and after trust, what turns them hostile. One to three tight paragraphs the AI can act on.

An encounter is any authored moment of consequence — not just combat.

Front matter: id (required), location, involves (NPC/entity ids in play), optional chapter / side_quest, optional min_players / max_players (set these only for a side quest sized for a subset of the table).

Body: what happens, and how the DM should adjudicate the branches — "if the party does X … / if they do Y …", with named checks and DCs, the SRD stat blocks for any fight, and what's at stake. Loot and forward consequences live here, not in a separate reward step — so an NPC can be carrying the item the party would otherwise only find after beating them.

The starting values for a campaign's mutable state — party location, story flags, NPC status — kept out of the static Markdown so the pack stays clean and diffable in git. The current Master tracks live state in its own store rather than rewriting this file; it documents the shape a pack expects and gives a new table a clean slate to start from. Optional.

Both are optional, lightweight tags — not a directory structure.

• Chapters group content into roughly one-level arcs. Add a chapters: outline to campaign.md (id / title / level_range / summary per entry), then set chapter: <id> on the location/npc/ encounter files that belong to each. Generation deliberately produces only the outline plus the first chapter; later chapters are generated (or written) separately, once the party is near them.
• Side quests use side_quest: <id> instead of chapter for a short, self-contained 1–2 encounter detour that doesn't touch the main progression — handy when the table is short a player for a session.

A pack that uses neither (like sable-ravine) is exactly as valid as one that uses both.

Set in campaign.md front matter, enforced by Master at the tool-call layer, not left to the AI (design doc §9):

Everything in a pack that ships in this repo (or is generated by default) must be original, SRD 5.1-legal content: no proprietary terms ("Dungeons & Dragons", "D&D", "WotC"), no named published characters, no non-SRD monster names, no setting flavor text, no reproduced module plots or locations. Tone- and genre-inspired is fine; direct reuse is not. stat_block_ref values must be plain SRD types. See CLAUDE.md and design doc §6.4 / §12.

(A pack you keep privately on your own Master is yours — this constraint is about what's committed here and what Master generates out of the box.)

1. Put the pack directory somewhere Master can read.
2. Admin panel → Campaign tab → set the Campaign Pack Directory to its path → Bind Pack. Binding runs the same validation described above and reports any error.

Or pull a whole shelf of ready-made packs: Campaign tab → Install the campaign pack library from layforge.org.