{
  "version": "v4",
  "schema_version": 3,
  "date": "2026-10-28",
  "license": "CC0-1.0",
  "source_file": "data/core_books.csv",
  "source_sha256": "5876380a1bde6ad04b860c71414c9843bc8fc7e03cbcef2e65b92e76d3e69de3",
  "source_records": 413,
  "system_count": 305,
  "family_count": 32,
  "counts": {
    "classified": 212,
    "standalone": 14,
    "unclassified": 79
  },
  "csv_sha256": "b2a43cee48540a29611645115b07676cf73475ab3255b26e3644585a2803b708",
  "rules_sha256": "2af1f888d2532211c7ef8b808991c360645ef0aa5115de161127c0d138f01f33",
  "families": [
    {
      "id": "2d20",
      "name": "2d20"
    },
    {
      "id": "adventure-game-engine-age",
      "name": "Adventure Game Engine (AGE)"
    },
    {
      "id": "basic-role-playing",
      "name": "Basic Role-Playing"
    },
    {
      "id": "burning-wheel",
      "name": "Burning Wheel"
    },
    {
      "id": "cortex",
      "name": "Cortex"
    },
    {
      "id": "cypher-system",
      "name": "Cypher System"
    },
    {
      "id": "dnd-d20",
      "name": "D&D / d20"
    },
    {
      "id": "d6-system",
      "name": "D6 / OpenD6"
    },
    {
      "id": "earthdawn-step-system",
      "name": "Earthdawn / Step System"
    },
    {
      "id": "fate-fudge",
      "name": "Fate / Fudge"
    },
    {
      "id": "forged-in-the-dark",
      "name": "Forged in the Dark"
    },
    {
      "id": "gumshoe",
      "name": "GUMSHOE"
    },
    {
      "id": "gurps",
      "name": "GURPS"
    },
    {
      "id": "hero-system",
      "name": "HERO System"
    },
    {
      "id": "into-the-odd-nsr",
      "name": "Into the Odd / NSR"
    },
    {
      "id": "kids-on-bikes",
      "name": "Kids on Bikes"
    },
    {
      "id": "mutants-and-masterminds",
      "name": "Mutants & Masterminds"
    },
    {
      "id": "mork-borg",
      "name": "Mörk Borg"
    },
    {
      "id": "palladium-megaversal",
      "name": "Palladium Megaversal"
    },
    {
      "id": "powered-by-the-apocalypse",
      "name": "Powered by the Apocalypse"
    },
    {
      "id": "resistance-system",
      "name": "Resistance System"
    },
    {
      "id": "rolemaster",
      "name": "Rolemaster"
    },
    {
      "id": "roll-and-keep",
      "name": "Roll and Keep"
    },
    {
      "id": "saga",
      "name": "SAGA"
    },
    {
      "id": "savage-worlds",
      "name": "Savage Worlds"
    },
    {
      "id": "storyteller-storytelling",
      "name": "Storyteller / Storytelling"
    },
    {
      "id": "torg-masterbook",
      "name": "Torg / MasterBook"
    },
    {
      "id": "traveller",
      "name": "Traveller"
    },
    {
      "id": "unisystem",
      "name": "Unisystem"
    },
    {
      "id": "vortex",
      "name": "Vortex"
    },
    {
      "id": "warhammer-d100-lineage",
      "name": "Warhammer d100 lineage"
    },
    {
      "id": "year-zero-engine",
      "name": "Year Zero Engine"
    }
  ],
  "previous_version": "v3",
  "changes": [
    "Merge Storyteller System and Storytelling System into Storyteller / Storytelling, using a new family ID; retire both old IDs in v4.",
    "Preserve all 305 system identities, assignment statuses, community identities, direct system associations and original evidence dates.",
    "Rebuild affected family associations and collapse duplicate family/community edges. No new collection or source verification."
  ],
  "discord": {
    "servers_file": "v4-discord-servers.csv",
    "servers_sha256": "f284de36436e4965db87aea9a503af50d3c10384f827fafb77bc460c4b60a56f",
    "mappings_file": "v4-discord-mappings.csv",
    "mappings_sha256": "563b22465d37882ff75d52b2b60539d66e8c5dc434fe17d342cd2e6f0551d561",
    "server_count": 46,
    "mapping_count": 147,
    "mapped_system_count": 90,
    "mapped_family_count": 26,
    "checked_on": "2026-10-18",
    "coverage": "Initial non-exhaustive research across publisher, creator and fan communities; zero associations mean no confirmed mapping in this release. Internal channels were not audited. No member counts are part of this classification.",
    "member_count_documentation": "https://docs.discord.com/developers/resources/invite#get-invite",
    "research_gaps": [
      "No usable public invite confirmed for Unisystem, SAGA, Roll and Keep, Vortex, HERO System or Warhammer d100 lineage in this pass.",
      "Some located Burning Wheel HQ invites, two Green Ronin community links and a DungeonCrawlers link returned Discord 404 and were excluded.",
      "One invite advertised on a HERO forum resolved to an unrelated Mythic GME server and was excluded.",
      "Delta Green publisher lists communities but requests asking for current invitations; no server was added without a verified public invite.",
      "This is primarily English-language discovery, with some multilingual communities; it is not a census of public Discord servers."
    ]
  },
  "reddit": {
    "communities_file": "v4-reddit-communities.csv",
    "communities_sha256": "67288d45ca031c41c9a2e049161c68a39d36615cdd484dc3870f375ffe55fb14",
    "mappings_file": "v4-reddit-mappings.csv",
    "mappings_sha256": "3d3d9066cfc9924314ddc9f87cc67782e736efa6f8ef56fafb198bf125b21857",
    "community_count": 105,
    "mapping_count": 215,
    "mapped_system_count": 121,
    "mapped_family_count": 29,
    "known_fullname_count": 72,
    "checked_on": "2026-10-18",
    "coverage": "Initial non-exhaustive research, primarily English-language, with public community pages, descriptions and discussions. Some public evidence was served from web caches. No edge means no confirmed association in this release. Subscriber lookup endpoints are supplied but not live verified; no counts were collected.",
    "subscriber_count_documentation": "https://www.reddit.com/dev/api/#GET_r_%7Bsubreddit%7D_about",
    "weekly_visitors_documentation": "https://support.reddithelp.com/hc/en-us/articles/41043361207316-Understanding-weekly-visitors-and-contributions-on-Reddit",
    "research_gaps": [
      "Direct Reddit metadata requests returned HTTP 403. Public pages loaded in Chrome initially, then browser requests were blocked; remaining evidence used the web source, sometimes cached. No live subscriber lookup was verified.",
      "33 community records lack a retrieved Reddit t5 fullname. Names, public URLs and evidence remain available; verify identity before collecting future counts.",
      "r/herosystem could not be confirmed; r/Hero_Games is included with its own reviewed identity. Some additional candidates including r/HeartRPG, r/BladeRunnerRPG and r/rolemaster could not be confirmed in this pass.",
      "r/OnyxPathRPG was not mapped to Exalted or Chronicles of Darkness: its own description directs White Wolf games to r/WhiteWolfRPG. A publisher connection alone is insufficient.",
      "Generic r/rpg and unrelated video-game or franchise fandoms are not assigned automatically to catalogue systems. Dedicated community discovery remains incomplete, especially outside English."
    ]
  },
  "family_mergers": [
    {
      "from_ids": [
        "storyteller-system",
        "storytelling-system"
      ],
      "to_id": "storyteller-storytelling",
      "name": "Storyteller / Storytelling",
      "reason": "Owner-requested consolidation of related rules families for popularity reporting. This does not assert identical rules, settings or distinct audiences."
    }
  ]
}