Duel Hall is a small, independently-run hobby project — a couple of head-to-head browser games, currently just Card Duel. This page explains what data the site collects and why, in plain terms.
What we collect
- If you don't sign in: nothing leaves your browser. Local pass-and-play and vs-CPU games run entirely client-side; your theme and sound preferences are stored only in your own browser's local storage.
- If you sign in with Google (only needed for online multiplayer, friends, and profile stats): we receive your name, email address, and profile photo from Google, via Firebase Authentication. We don't see or store your Google password.
- Game data: match results, turn counts, and a move-by-move log of games you finish while signed in, so your profile can show stats like win rate and favorite card.
- Friends: a short shareable friend code tied to your account, and the display name/photo of anyone you add as a friend.
- Profile: an optional nickname and a chosen avatar (one of a fixed set of in-game character icons — no photo upload), plus a chess-style skill rating that updates after each online match.
- Presence: a rough "last active" timestamp, refreshed periodically while you have the site open, so friends can see if you're likely online — plus a coarse status like "in a match" when applicable.
- Approximate location: your city and country, looked up from your IP address (not GPS — we never ask for or use your browser's precise-location permission) once per sign-in, shown to friends and other online players next to your name in the lobby. This is approximate and can be off by a city or more.
- Live match state: while an online match is in progress, both players' hands, tables, and chat (a fixed set of emoji and preset quick messages only — no free text) are stored so the game can sync between two browsers in real time.
- Analytics (everyone, signed in or not): we count visits so we can see whether anyone's playing and what to fix. Two things run on every page:
- A first-party counter of our own — it increments plain numbers ("pageviews today", "matches played", "visitors by country") in our Firestore. It uses no cookies. It derives an approximate country from your IP via a third-party lookup (api.country.is) and stores only the two-letter country code, aggregated — never your IP, never anything that identifies you.
- Google Analytics 4 (measurement ID
G-38GLJ32013), with IP anonymisation on, for aggregate traffic, referrer and device reporting. Google is the data processor for this; see Google's own policies. You can block it with any ad-blocker or "Do Not Track"-style extension and the site works exactly the same.
No advertising trackers, no data brokers, no cross-site profiling — just "is this thing being used."
Where it's stored
Everything above is stored in Google Firebase (Firestore), Google Identity/Auth, and Google Analytics — this project doesn't run its own database. Aside from the aggregate analytics described above, there are no advertising or cross-site trackers.
Who it's shared with
Your account and game data isn't sold, shared with advertisers, or used for anything beyond running the game — showing your name/photo to friends you've added, syncing a live match between two players, and displaying your own stats back to you. The only third parties involved are infrastructure providers doing exactly one job each: Google (Firebase/Auth/Analytics), and api.country.is (the country-from-IP lookup for the visitor counter). No data brokers, no ad networks.
Your choices
You can sign out at any time from the account menu. To have your account data removed entirely, contact the email below and it will be deleted from Firestore.
Contact
Questions about this policy: [email protected]
