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Cards Against Humanity

Cards Against Humanity logo

A self-hosted, multi-device party card game. Players join a room from their phones; one rotating Card Czar picks the winning answer each round. Uses the official deck (71 packs, 4,655 white cards and 1,037 black cards) bundled under CC BY-NC-SA 2.0 — this is a non-commercial private build.

URL: cah.xmsystems.co.uk

Warning

This game contains adult humour and offensive content. Suitable for players 18+.

How to Play

  1. One player creates a room and shares the 4-letter room code with everyone else.
  2. All players join via the room code on their phones — minimum 3 players to start.
  3. The host configures packs, hand size, and the points target in the lobby, then deals.
  4. One player is the Card Czar each round. The Czar plays a black card — either a question or fill-in-the-blank.
  5. All other players secretly choose the funniest white card(s) from their hand to answer it.
  6. The Czar reads all answers aloud anonymously and picks their favourite. The winner scores an Awesome Point.
  7. Everyone draws back up to a full hand. The Czar role passes left each round.
  8. First player to reach the configured points target wins.

Note

Pick 2 and Pick 3 black cards are fully supported — players submit multiple white cards in order.

Pages

Cards Against Humanity handles host and player views within the same single-page application — there are no separate /host or /player URLs. All interaction happens on the main game page, with the interface adapting based on whether you are the current Card Czar or a regular player.

URL Purpose
/ Full game — lobby, gameplay, and results all in one

Players join from their own phones using the same URL and the 4-letter room code. The game experience on each device adapts to the player's current role.

Architecture

Cards Against Humanity has a more structured layout than the other games, with the frontend and backend separated into their own directories:

/ssd/docker/appdata/cah/
    server/
        server.js       Express app — static files, /healthz, /api/packs, WebSocket layer (/ws)
        game.js         Room class — full game state machine
        deck.js         Loads deck, builds shuffled draw piles from selected packs
    public/
        index.html      Single-page client
        styles.css
        app.js
    data/
        official-deck.json   71 official packs
    Dockerfile
    package.json

Unlike the other games which proxy WebSockets via nginx, CAH is accessed directly via Traefik on Titan — nginx is not involved in routing for this game.

nginx Config

There is no nginx server block for Cards Against Humanity. Traefik on Titan routes cah.xmsystems.co.uk directly to the cah container at 172.20.0.25:3010 (mapped from internal port 3000).

Backend

Docker Compose: /ssd/docker/docker-compose/cah/docker-compose.yml

networks:
  phobos-network:
    external: true

services:
  cah:
    build: /ssd/docker/appdata/cah
    image: cah:local
    container_name: cah
    restart: unless-stopped
    environment:
      - PORT=3000
    ports:
      - "3010:3000"
    networks:
      phobos-network:
        ipv4_address: "172.20.0.25"

Dockerfile: /ssd/docker/appdata/cah/Dockerfile

FROM node:22-alpine
WORKDIR /app

COPY package*.json ./
RUN npm install --omit=dev --no-fund --no-audit

COPY server ./server
COPY public ./public
COPY data ./data

ENV NODE_ENV=production
ENV PORT=3000
EXPOSE 3000

USER node

HEALTHCHECK --interval=30s --timeout=4s --start-period=8s --retries=3 \
  CMD wget -qO- http://localhost:3000/healthz || exit 1

CMD ["node", "server/server.js"]

Rebuilding

cd /ssd/docker/docker-compose/cah
docker compose build
docker compose up -d --force-recreate

Game Settings

Setting Range Default
Points to win 1–20 8
Hand size 5–14 10
Packs Any of 71 official packs Base Set

Room codes use an unambiguous alphabet (no 0/O/1/I) and rooms are reaped after 30 minutes idle.

File Locations

File Path
Hub info page /ssd/docker/appdata/nginx/game-info-cah.html
Node.js server /ssd/docker/appdata/cah/server/server.js
Game state machine /ssd/docker/appdata/cah/server/game.js
Deck loader /ssd/docker/appdata/cah/server/deck.js
Client frontend /ssd/docker/appdata/cah/public/
Card data /ssd/docker/appdata/cah/data/official-deck.json
Dockerfile /ssd/docker/appdata/cah/Dockerfile
Docker Compose /ssd/docker/docker-compose/cah/docker-compose.yml
Traefik config cah.yml on Titan