1. Information we collect
When you sign in, your chosen login provider supplies the account identifier needed to recognize you and any name, avatar or email you authorize it to share. We do not receive your third-party account password. We also collect your game profile, matches and rankings, room participation, virtual item and reward records, and the feedback and contact details you submit. Using the service generates IP addresses, device and browser information, access records and error reports. To identify problems in loading, sign-in, joining a table and checkout, we record step times, outcomes, duration, platform, interface language and app version. Events use a random session ID and are associated with your game account after sign-in. Behavioral events do not contain chat content, passwords, sign-in tokens or payment card details. Raw behavioral records have a 90-day retention period with periodic cleanup.
2. How we use information
We use this information to maintain accounts, provide games and social features, record virtual items, respond to feedback, resolve faults and keep the service fair and secure. Without information needed for a core function, we may be unable to provide it. Public lessons require no game account, and contact details in feedback are optional. We will provide appropriate notice before using personal information for a purpose inconsistent with this Policy.
3. Legal bases
Where applicable law requires a legal basis, we process information needed for accounts, games and support to perform our service agreement. We rely on legitimate interests in preventing abuse and protecting security, taking your rights into account, and on legal obligations for required retention or disclosure. Optional processing that needs consent will be presented separately, and you may withdraw consent. Accepting the Terms is not consent to marketing.
4. Sharing and public information
Your name, avatar and relevant results may be visible to players at your table or leaderboard users. We share necessary information with authentication providers such as Google/Firebase and Telegram, delivery and hosting providers such as Cloudflare, and infrastructure providers to operate the service. We may also disclose information to meet legal obligations or protect lawful rights. We do not sell personal information or share it for cross-site targeted advertising. Third parties' own services are governed by their privacy policies.
5. Cookies and similar technologies
We use necessary cookies and device storage for sign-in, security and preferences such as language and sound. You can clear or restrict storage in your browser or device settings, which may affect features and saved preferences. We do not currently use advertising tracking cookies. We will offer a choice before introducing non-essential tracking that requires consent.
6. Retention
We keep information only for as long as needed for the purposes in this Policy, considering account activity, the purpose of each record, disputes and legal obligations. After a valid deletion or account closure request, information no longer needed will be deleted or anonymized. Information that must be retained for law or disputes is used only for those purposes. Backup copies are removed progressively as backups are renewed.
7. Security
We use reasonable technical and organizational measures to protect personal information, including protection during transmission, access controls and necessary backups. No online service can guarantee absolute security. If a security incident affects your rights, we will take response and notification measures required by applicable law. Do not include passwords or unrelated sensitive information in feedback.
8. International processing
We and our providers may process information outside your country or region, where data protection rules may differ. Cross-border transfers are subject to applicable requirements for notice, consent or other lawful transfer conditions. You may contact us to ask about processing locations and the relevant protection arrangements.
9. Your rights and contact
The mahjchina team is responsible for the service's processing of personal information. Email support@mahjchina.com or use website feedback to request access, correction, deletion or account closure. Subject to applicable law, you may also request a copy or portability of your data, restrict processing, object to processing based on legitimate interests or withdraw consent. Withdrawal does not affect the lawfulness of earlier processing. We may verify your identity and will respond within applicable legal deadlines. You may also complain to the data protection authority with jurisdiction where you live.
10. Children and Policy updates
Online game accounts are not intended for people under 18 or the higher age required locally. Please contact us if you believe we have collected information from a child who does not meet that requirement. We will date updates to this Policy and notify you of material changes through the website or app, obtaining separate consent where required by law.
11. Referral and usage measurement
We use random browser identifiers, referral codes, visits, game starts, results and payment records for first-party promotion measurement. We do not collect other referral URL parameters, full page URLs or advertising-platform identities for this purpose. Browser identifiers and visit details are retained for up to 90 days; first and recent sources remain with account records. Clearing browser data changes the anonymous identifier; linking an account preserves its attribution.
12. Purchase information
We process necessary order and transaction information with the relevant app store, payment provider or reseller to complete purchases, deliver items and handle refunds. The payment recipient processes payment and billing details under its privacy policy; your checkout or receipt identifies the channel. mahjchina does not receive full card numbers or card security codes.
13. Website analytics
Allow Google Analytics to use analytics cookies to measure page visits, clicks to enter the game and calculator result categories and duration ranges, grouped by fixed sources such as search or AI referrals. The source category and entry page are stored in this tab only and expire after 30 minutes of inactivity. Google processes browser, device and visit data; we do not send tiles, entered values, account, chat or payment information. You can change your choice in the footer at any time.