Foundry VTT

Virtual tabletop platform for TTRPGs. Node.js server, WebSocket-based, extensible via modules and game systems. Current version: v13.

Key Concepts

• Module: Extends/modifies Foundry functionality (like a plugin)
• System: Defines game rules, data schemas, sheets (e.g., dnd5e, pf2e)
• Document: Core data type (Actor, Item, Scene, JournalEntry, ChatMessage, Macro, RollTable, Playlist, Cards)
• Application: UI window class (legacy Application v1, modern ApplicationV2)
• Hook: Event system for lifecycle/render/document events

Module Quick Start

mymodule/
├── module.json          # Package manifest (required)
├── scripts/
│   └── main.mjs         # Entry point (esmodules)
├── templates/            # Handlebars .hbs files
├── styles/               # CSS files
├── packs/                # Compendium data
└── lang/
    └── en.json           # Localization

Minimal module.json:

{
  "id": "my-module",
  "title": "My Module",
  "version": "1.0.0",
  "compatibility": { "minimum": 12, "verified": "13" },
  "esmodules": ["scripts/main.mjs"],
  "styles": ["styles/module.css"]
}