The short version: Chess Duel has no in-app purchases and no email or password sign-up. You pick a display name, and your progress is saved on your device. To make online play possible, we keep a small profile in Google Firebase: your display name, your online rating and record, a scrambled identifier for your device, and the online games you play. We never sell it, and you can delete it from inside the App at any time. The App is free because it shows ads from Google AdMob. Google collects some device information to deliver them (see Section 5), and you can control that.
This Privacy Policy explains how the mobile game Chess Duel ("the App", "we", "us") handles information when you use it.
We collect only what the App needs to work. We do not ask for your real name, email address, phone number, contacts, location, photos, files, microphone or camera.
| Data | Why | Where it is kept |
|---|---|---|
| Display name: the name you type when you first open the App. It can be anything and does not need to be your real name. | Shown to you, and to opponents in online games | Your device, and Firebase if the App is online |
| Device key: a one-way, salted hash of your device's system identifier (Android ID on Android; an app-specific identifier kept in the Keychain on iOS) | Recognising your device so your name and rating come back after a reinstall, without an account | Your device, and Firebase |
| Anonymous sign-in ID: a random ID issued by Firebase Authentication | Letting the server check that only you can move your pieces or change your profile | Firebase |
| Online profile: online rating, wins, losses and draws | Matchmaking and showing your rank | Firebase |
| Online games: the moves played, both players' display names and ratings, the result, draw offers, preset emotes, and "last seen" timestamps | Playing the game live, and detecting when a player has left | Firebase |
The raw device identifier never leaves your device. Only the hash (the device key) is sent, and it cannot be turned back into the original identifier.
So you can pick up where you left off, the App saves the following in your device's standard app storage. It is not sent to us.
Journey, puzzles and Pass & Play work fully offline and send nothing over the network.
Online features use two Google Firebase services: Firebase Authentication (anonymous sign-in only) and Cloud Firestore (the database for profiles and games). When the App connects, it creates or refreshes your profile, even if you do not start an online game, so your name and rating are ready when you do. Google processes this data on our behalf as a service provider. As with any internet service, Google's servers also receive technical data such as your IP address in order to deliver the service.
See the Firebase Privacy and Security page and the Google Privacy Policy.
All traffic between the App and Firebase is encrypted in transit (TLS). Server security rules make sure only you can change your profile, only the players in a game can move in it, and nobody can browse the list of player profiles.
In an online game, your opponent sees your display name, your online rating, your moves and any preset emotes you send. There is no free-text chat. Other players cannot see your device key, and they cannot look up your profile.
Please do not use your real full name, or anything else that identifies you, as your display name.
The App shows ads served by Google AdMob. To deliver, measure and protect ads from fraud, Google may automatically collect from your device:
Google collects this under its own policies; we never receive it. See How Google uses information from sites or apps that use its services and the Google Privacy Policy. We do not send your display name, device key or games to the advertising SDK.
Ads appear in these places only:
Consent (EEA, UK and Switzerland): before any ad is requested, the App asks for your consent through Google's User Messaging Platform where the law requires it. You can change your answer later in Settings → Ad privacy options.
Personalised ads elsewhere: you can opt out on your device at Settings → Google → Ads → Delete advertising ID (Android), or turn off Allow Apps to Request to Track (iOS).
Your online profile stays until you delete it (see Section 7). Records of online games remain in the database because they are part of your opponent's history too. Once you delete your profile, those records are no longer linked to a profile or to your device. Information stored only on your device stays until you delete it in the App, clear the App's storage, or uninstall the App.
In the App: open Settings → Delete my data. This deletes your online profile (name, rating and record) and your anonymous sign-in ID from Firebase, and erases all progress stored on your device. It cannot be undone.
Other requests: if you can no longer open the App, or you also want the records of your past online games removed, contact us through the developer contact details on the App's Google Play page, and include the display name you used. We will delete the data within 30 days and confirm by reply.
Uninstalling the App removes the data on your device, but not your online profile. Use one of the options above for that.
| Data type | Collected | Shared | Purpose |
|---|---|---|---|
| Personal info → Name (display name) | Yes | No | App functionality, account management |
| Device or other IDs: hashed device key and anonymous sign-in ID (us); Advertising ID (Google AdMob) | Yes | Yes* | App functionality, account management; advertising, fraud prevention |
| Location → Approximate location (from IP, by Google AdMob) | Yes | Yes* | Advertising, fraud prevention |
| App activity → App interactions (ad interactions, by Google AdMob) | Yes | Yes* | Advertising, analytics |
| App activity → Other actions (online game moves and results) | Yes | No | App functionality |
| App info and performance → Crash logs, diagnostics (by Google AdMob) | Yes | Yes* | Analytics, fraud prevention |
| Contacts, photos, files, audio, messages, financial info, health, web history, precise location | No | No | — |
* Collected by the Google Mobile Ads SDK and processed by Google for advertising.
Chess Duel is a general-audience game and is not directed at children under 13, and its ads are not configured for children. We do not knowingly collect personal information from children under 13. Because online play shows players' self-chosen names, parents may prefer that younger children stick to the offline modes, which send nothing to our servers. If you believe a child under 13 has created an online profile, contact us through the App's Google Play page and we will delete it.
We rely on Google Firebase's infrastructure, encryption in transit and server-side security rules to protect data. No method of electronic storage is completely secure, but we keep what we collect to the minimum needed to run the game.
Depending on where you live, laws such as the GDPR, the UK GDPR and the CCPA give you the right to access, correct, delete or export your personal data, and to object to its processing. You can change your display name in Settings and delete everything with Delete my data. For any other request, use the developer contact on the App's Google Play page. We have never sold personal information and do not intend to.
We may update this policy, for example if the App gains new features. Changes will be posted on this page with a new "Last updated" date. If a change affects what we collect, we will also mention it in the App's release notes.
Contact
Questions about this policy or requests about your data: use the developer contact details on the Chess Duel page in the Google Play Store.