Privacy

You can play as a guest without a game account. Optional FiddlerCrab accounts add cloud saves, private online games and opt-in matchmaking with other players. This notice covers the Theme Chess website, browser game and native versions, including optional prerelease testing. Describing native features here does not announce availability on an app store.

Theme Chess uses no advertising or marketing tracking pixels, and loads its fonts locally. It uses aggregated Vercel Web Analytics page views as described below. Optional paid collections use Stripe website checkout or Apple In-App Purchase in native builds that offer purchases. The password gate and public legal pages contain no analytics scripts; the legal pages also contain no game scripts or embedded sign-in widgets.

Who is responsible?

The controller responsible for this processing is:

Email: hello@fiddlercrab.eu
Telephone: +49 30 69204740

Represented by Dr. Clemens Dorian Chaskel. Please contact us at the email or postal address above for privacy questions or requests.

What information is used, and why?

Visiting the website and restricted review areas

Our hosting provider receives the network information needed to deliver pages and game assets, including your IP address, request time, requested address, browser/request headers and response or error information. This supports delivery, security, abuse prevention and troubleshooting. Where a review area uses an access password, that password is checked by our access handler; it is not a game-account password. Successful restricted access sets the cookie described below. Public launch pages do not require that cookie.

We rely on our legitimate interests in operating a reliable, secure service and protecting any restricted review areas (Article 6(1)(f) GDPR).

Aggregated page analytics

We use Vercel Web Analytics on the production themechess.com website, browser game, store and Learn guides to understand page usage and improve the service. It does not run on the password gate or public legal pages, in native app builds, or on local development and preview deployments.

Reports are aggregated and can include page paths, visit times, referring origins, device type, operating system and browser details, and approximate location. Vercel describes a hash derived from incoming requests for visitor counting and says the visitor-session identifier is discarded after 24 hours. Our integration does not set analytics cookies. Requests still involve processing network information; aggregation and daily visitor hashing are not a guarantee of absolute anonymity. See Vercel's Web Analytics privacy documentation.

Before sending a page view, our client removes all URL query parameters and fragments. Referrers are restricted to origins; visits with a more detailed referrer are not reported. We do not include account IDs, email addresses, moves, game IDs or feedback, and do not send custom events. We do not report page views when the browser signals Do Not Track or Global Privacy Control.

We rely on our legitimate interests in understanding the use of the website and improving the service (Article 6(1)(f) GDPR). The objection rights described below also apply.

Guest play and your device

Guest game history, saved games and your chosen settings are kept in your browser or, in a native iPhone/iPad build, on your device. Saved moves allow you to study a game in replay. Settings include appearance, accessibility and assistance choices, camera/SpaceMouse preferences and private opponent-piece overrides. Guest games are not automatically uploaded to an account. You can choose to import them into a signed-in library.

The game may contact Supabase to check which sign-in methods are available or restore an existing session, even when you have not started an online game. Supabase then receives the network information associated with that request. Availability checks support functioning account controls under our legitimate interests; restoring your chosen sign-in provides the requested account service. Local play and already-saved positions can continue without a live account connection; online moves and cloud synchronisation require connectivity.

Optional FiddlerCrab account

Supabase Auth handles email/password sign-in and the Google or Apple sign-in you choose. Account data includes an account ID, email address, linked provider identifiers, session/security information and basic profile information supplied by the chosen provider, such as a name or avatar address. Passwords are not included in game saves.

Google or Apple is contacted for sign-in or account linking only after you choose that provider. The provider receives the authentication request and handles your sign-in under its own Google privacy policy or Apple privacy policy. Linking a provider associates another permitted sign-in method with your FiddlerCrab account. Email sign-in can request confirmation and password-reset messages through Supabase Auth. We send no marketing email.

The FiddlerCrab account service is shared by games connected to this platform. Account credentials, linked sign-ins and password changes are shared. Game records carry a game identifier, and the Theme Chess interface loads this game's library. Owner and participant access rules protect the records; sharing the account service does not make your library visible to other players.

Private account appearance

When signed in, a separate per-game preference record can contain your preferred collection, private opponent display choice, board, lighting, finish, background colour, glass transparency, app theme, coordinates and cape preference, with a revision and server timestamp. Owner-based access rules limit this record to your account. These settings can follow you across your own devices; they are not shared with opponents, placed in match records or used to grant a purchase.

Guest appearance stays local. Existing cloud settings take priority at sign-in; a new account may first adopt guest choices. Account-scoped device caches retain offline changes for that account, and guest appearance is restored at sign-out. SpaceMouse calibration, performance and reduced-motion settings remain device settings. This processing provides the appearance service you request under Article 6(1)(b) GDPR.

Cloud saves and online multiplayer

When signed in, your game library can synchronise game titles, moves/history, game configuration and appearance, record IDs, revisions and timestamps. Private online games store the participating account IDs, invitations/rematch requests, moves, published piece choices, draw/resignation actions, clocks, results and timestamps. These records allow players to resume several games and study their history.

Match data is available to the participating players and, for a targeted rematch, its named invitee. An unused ordinary invitation can be accepted by another signed-in player who has its link. Login emails and provider profiles are not included in shared match responses. A private opponent-piece override is never sent to the opponent or included in public match responses, PGN or shared profiles. When signed in, it may sync privately with your own account as explained below. There is no public chat or public player directory.

Choosing Play someone joins an optional search for another player. We store your account ID, chosen time control and piece collection, search ticket and heartbeat times, and an approximate chess skill rating. Your first level is self-assessed; completed random-player games update the estimate. Private games and games against the computer do not affect it. We use the estimate to prefer similarly skilled opponents and widen the search as you wait. It is a provisional estimate, not an official chess ranking.

Your matched opponent can see your starting skill estimate, the rating change for the game and your rated-game count, including whether the estimate is provisional. Only participants can read their match records. Other players cannot browse account profiles, email addresses, ratings or search tickets. Search counts describe players currently looking for a game, not everyone signed in. Searches stop being eligible after cancellation or a short heartbeat timeout. Skill records remain linked to your account until deletion; your own estimate is available when you use matchmaking again.

We process the information necessary for the account, cloud-save and online-game services you request under Article 6(1)(b) GDPR. An account is optional for local play; without the required account/sign-in data we cannot provide account-based features.

Purchases and restoring collections

Website checkout sends the selected collection, signed-in account reference, email where available, actual billing country and checkout consent/version/time to Stripe. Stripe checkout processes your payment and billing details. Direct German orders are sold by FiddlerCrab; covered foreign orders use Stripe Managed Payments through Link as merchant of record. The seller is identified at checkout and on the receipt. In native builds offering purchases, Apple processes Apple In-App Purchase payment details. See Stripe's privacy notice and Apple's privacy notice.

Our server verifies provider transactions and maintains normalized purchase records: the original account binding, provider and environment, collection identifier, original/latest transaction references, payment state, relevant timestamps and event references, and website consent version/time where applicable. Refunds, revocations and disputes can change access. We do not store full card numbers or raw signed Apple receipts in the game database. Restoring purchases verifies the transaction and original account binding; it does not transfer a purchase to another account.

We process these records to fulfil purchases and restore access under Article 6(1)(b) GDPR, meet applicable accounting/tax obligations under Article 6(1)(c), and investigate fraud, disputes and support requests under our legitimate interests in Article 6(1)(f). A purchase record may remain after account deletion for those purposes. Its direct Auth account reference is cleared; provider transaction references and a one-way account-binding fingerprint remain. This is pseudonymous retention, not a claim of anonymous or immediately erased financial records.

Feedback and contacting us

Submitted feedback and collection ideas contain your text, account ID, game identifier and submission time. They are available to FiddlerCrab for reviewing problems, considering new collections and improving the service, not to other players. Unfinished feedback and collection-idea drafts are kept separately in the current browser tab while you sign in. If you email us, we and our business email provider process your address, message and correspondence to answer you. Please do not include passwords or sensitive personal details in feedback or suggestions.

Our basis is the legitimate interest in answering enquiries and investigating feedback (Article 6(1)(f) GDPR), or Article 6(1)(b) where the enquiry concerns providing a requested service.

Cookies and browser storage

• Restricted review access, when used: __Host-themechess_beta is a signed access token that lasts up to seven days. It has Secure, HttpOnly and SameSite=Lax protections. It contains an expiry and random session value, not your game-account email or the password.
• Account session: when you sign in, Supabase session credentials are stored in this browser so your requested account features continue across visits. Native iPhone/iPad builds use the iOS Keychain for credentials and small sign-in-state records. Sessions are refreshed while valid; sign out to end the app's current session.
• Local play: local storage keeps the guest/account game library and the preferences you use. Session storage keeps an unfinished feedback draft or pending invitation for the current tab. These are functional game data, not advertising identifiers.

In native iPhone/iPad builds, the app uses device preferences for game libraries and settings, and temporary in-app storage for drafts and pending invitations. Exporting a game creates a temporary cache file and opens the iOS share sheet; you choose its destination. Copying an invitation or gallery link writes that link to your clipboard only after you select Copy. The app does not read your clipboard. Social sign-in and external legal/help links open the system browser. Native app builds do not run our Vercel page analytics.

This functional storage supplies requested access, saved progress, sign-in and preferences. We rely on the strictly necessary exception in section 25(2)(2) TDDDG for storage necessary to provide those requested services. This is separate from the page analytics described above, which does not set analytics cookies. GDPR bases for functional storage are the requested service and the security interests described above. Blocking or clearing functional storage can sign you out or remove local games and settings. Export games you want to keep before clearing browser data.

Service providers and international processing

Vercel hosts the website, gate handler and game assets through its global delivery network, and provides the page analytics described above. Requests can be processed in the United States and other countries where Vercel or its subprocessors operate. Supabase provides the FiddlerCrab authentication, database and game API; our selected database project is in Frankfurt, Germany. That regional database setting does not mean that all provider support, security or service processing stays in Germany.

Provider information about processing arrangements, subprocessors and available international-transfer safeguards, including EU Standard Contractual Clauses where applicable, is published in the Vercel data-processing addendum and Supabase data-processing addendum. These links do not represent an audit or certification of every account-specific agreement. Contact us for information about the arrangements applicable to your data. Google and Apple act separately for the sign-in services you choose; Stripe/Link and Apple also have their own obligations for the payment services they provide.

We do not sell player data. Access within FiddlerCrab is limited to operating, supporting and protecting the service. Information may also be disclosed where a binding legal obligation requires it (Article 6(1)(c) GDPR).

Apple TestFlight: if you choose to install a beta through TestFlight, Apple automatically collects beta installation, usage and crash information and shares it with us. This can include device and OS details, app versions, session/crash information and, depending on the invitation, your name and email address. Feedback or screenshots you submit through TestFlight are also shared with us. We use these records to diagnose problems and improve the beta. This is separate from our website analytics and is governed by Apple's TestFlight privacy information; it cannot be disabled using our website's Do Not Track setting.

How long is information kept?

A restricted-access cookie expires after seven days unless you clear it sooner. Local game data and settings remain until you remove them, clear site data or your browser removes storage. A tab's session storage lasts for its browser-managed session. We cannot remotely erase exported files or copies on other devices.

The 24-hour analytics visitor-session lifetime is not a promise that every aggregated report is deleted after 24 hours. Analytics reports follow Vercel's retention controls.

Cloud account data, private appearance preferences, saves, online games and submitted feedback remain associated with your account while you use those services, unless removed through the available controls or a valid deletion request. Individual library deletions are synchronised when online. Operational/security logs and backups follow the relevant provider's retention controls and are retained for service operation, security and recovery; a longer period may be necessary for a legal obligation or a specific legal claim. Deletion of active records does not immediately erase every backup or diagnostic record.

Deleting the shared account

The account menu offers Delete your FiddlerCrab account. This deletes the shared account and its associated cloud saves, private account appearance preferences, feedback and online match records across FiddlerCrab games using this platform. The other participant also loses access to those online matches. Export games first. Account deletion does not delete a Google or Apple account, reverse a payment, remove records required for financial/legal purposes, erase a separate restricted-access cookie or remotely remove local copies on other devices. You can also request deletion by contacting us.

Your rights

Subject to the GDPR's conditions, you can request access, correction, deletion, restriction and a portable copy of your personal data. You may object to processing based on legitimate interests for reasons relating to your situation. Where consent is used, you can withdraw it without affecting earlier lawful processing. Contact hello@fiddlercrab.eu; we may need to verify that the request concerns your data.

You can complain to a data-protection authority, including the Berliner Beauftragte für Datenschutz und Informationsfreiheit, or the authority where you live or work. We do not use player data for advertising profiles or solely automated decisions with legal or similarly significant effects.

Parents and guardians

Local play does not require registering a child. The game does not ask for dates of birth or operate an age-verification or parental-consent system. Please supervise children's online use and contact us if you have a question or request concerning a child's data.

Last updated: 3 November 2026. This notice describes the current service; material changes to data uses will be explained before they are introduced.