Bx Referee

B/X Referee

A solo play tool for Old-School Essentials (OSE). Point it at a B/X adventure module (PDF or Markdown) and it runs the game as referee, reading room keys, rolling encounters, and resolving combat while you control the party. It won't replace a human referee, but if you've got old modules collecting dust and nobody to run them, it's a way to actually play through them.

Prerequisites

• Claude Code version 1.0.33 or later.
• An OSE or B/X adventure module in PDF or Markdown format. Adventures are available from Exalted Funeral, DriveThruRPG (OSE), and DriveThruRPG (classic B/X).

Install

/plugin install bx-referee@osr-plugins

Skills

Skill	Invocation	Description
Referee	/bx-referee:referee	Orchestrator that routes to the right skill based on game context
Adventure	/bx-referee:adventure	Set up from module files, resume sessions, save state
Character	/bx-referee:character	Interactive character creation and level-up with SRD rules lookup
Exploration	/bx-referee:exploration	Dungeon/wilderness turn loop with movement, wandering monsters, searching, doors, traps, spells, encumbrance
Encounter	/bx-referee:encounter	Surprise, distance, reaction, flee/evasion, parley, spells
Combat	/bx-referee:combat	Initiative, attacks, damage, saving throws, morale, spells, death, XP and leveling

How it works

The referee is governed by an inviolable constitution that enforces player agency, information discipline, module fidelity, and neutral adjudication. The player always controls their characters. The referee describes the world and resolves actions, nothing more.

SRD references

The plugin includes a pre-cached copy of the OSE SRD (316 pages) as Markdown reference files. A docs map system with monster and spell submaps lets each skill find and read the exact rule it needs without network calls or script execution.

Adventure flow

1. Setup. Point the adventure skill at a module file (PDF or Markdown). It surveys the module, builds a location index, and checks for existing characters or parties before creating new ones.
2. Scene-setting. The referee reads the module's introductory material and presents the player-facing background, rumors, and opening situation.
3. Exploration. Turn-by-turn dungeon or wilderness loop with wandering monster checks, searching, doors, and traps.
4. Encounters. Surprise, distance, reaction rolls, flee/evasion, parley, with handoff to combat when fighting starts.
5. Combat. Initiative, attacks, damage, saving throws, morale, spells, and death.
6. Save/resume. Session state is persisted to Markdown files and can be resumed later.

Scope

The plugin covers dungeon and wilderness exploration for the B/X level range (levels 1–14), including combat, encounter resolution, character advancement, encumbrance tracking, and spell casting both in and out of combat. High-level play and domain management (strongholds, followers, mass combat, ship combat) are intentionally out of scope.

Adventure state

Each adventure lives in adventures/<name>/ with:

• PARTY.md: party roster with current HP, equipment, and XP
• SESSION.md: session timeline, exploration log, current situation
• LOCATIONS.md: indexed keyed locations from the module (with path to module file)

Licensing

Open Game License v1.0a

All rules text and tables in the SRD reference files (skills/referee/references/srd/) are Open Game Content used under the Open Game License v1.0a. The full license text and Section 15 copyright notice chain are in LICENSE-OGL.

Old-School Essentials third-party license

The use of the Old-School Essentials name and compatibility logo is permitted under the Old-School Essentials Third-Party License from Necrotic Gnome.

Old-School Essentials is a trademark of Necrotic Gnome. The trademark and Old-School Essentials logo are used with permission of Necrotic Gnome, under license.

This is not an official Old-School Essentials product published by Necrotic Gnome.

Project code

All skill prompts (SKILL.md files), Python scripts, and docs map files are original work and are not Open Game Content. See LICENSE-OGL for the Product Identity designation.