These terms govern your use of the mobile game Number Duel (com.ikarhan.number_challenge, the "App"). How personal data is processed is described in a separate document: the Privacy Policy. The two are read together.
The parties to this agreement are İsmail KARHAN (independent developer, Türkiye — the "Developer"), who develops and operates the App, and the individual using it (the "Player").
Using the App means accepting these terms. There is no separate tick box; the terms and the Privacy Policy are linked at the points where you register, set a display name and claim a username, and are always reachable in-app from Settings → Terms of service. If you do not accept these terms, do not use the App; §10 explains how to stop.
The App is not directed at children under 13. Players under 18 may use the App only with the knowledge and permission of a parent or guardian.
The App is a puzzle game about finding your opponent's secret number in as few guesses as possible. It offers three modes: against a bot on your device (works offline), private-room matches created with a six-character code, and ranked matches paired by rating. The online modes require a connection to the server the Developer operates.
The App is free and shows advertising. The only in-app purchase is a one-time Remove Ads entitlement (§7).
On first launch the App creates an anonymous account without asking you to register. That account is tied to a session stored only on that device. If you uninstall the App, reset your device, or the session becomes invalid, the guest account and its progress cannot be recovered. To make your progress durable, link the account with Google or with an e-mail and password.
With a linked account, progress survives a change of device. You are responsible for keeping your credentials confidential and for activity carried out through your account. If you believe your account has been used without your permission, tell us at the address in §12.
If the account you are linking already owns another profile, the App shows you both and asks which one to continue with. Ratings, statistics and achievements are never merged; the profile you do not choose becomes unreachable from that device. Only a purchased Remove Ads entitlement follows the profile you keep.
Your display name and username are visible to other players in matches, room previews, leaderboards, season records and notification text. These fields are the only user-generated content in the App; there is no chat, messaging or image sharing.
A display name must be 3–20 characters and must not contain:
A username additionally has a format rule: 3–20 characters, starting with a letter, containing only lowercase letters, digits and underscores. Some names and usernames are refused outright by the server. Where a name that breaks the rules gets through anyway, the Developer reserves the right — on a report or on their own initiative — to reset the name, revoke the username, and close the account for repeated violations. A player whose name is reset may choose a new one that follows the rules.
You can report a player from inside the App (leaderboard, match history, room preview and result screen). Reports are read by the Developer; they are never passed to the reported player and the reporter's identity is not disclosed. A report does not stop you being matched with that player again. The App has no player-blocking feature.
The following are prohibited:
Online matches are timed: a turn whose time runs out is "burned", and three burned turns lose the match. Abandoning a match, disconnecting or closing the app during a ranked match is recorded as a forfeit and affects your rating. This protects your opponent's time.
Depending on the severity of a violation, the Developer may reset a name, correct a rating, exclude a player from ranking, or close an account.
Ranked matches change your rating (ELO), and your rating determines your league. Rating and league are in-game indicators; they have no monetary value and cannot be transferred.
Seasons last four weeks. At the end of a season the standings are frozen, your result is recorded, and your rating is softly reset toward the centre: the new rating moves half of the distance between 1000 and your old rating (with a floor of 100). This lets everyone compete again at the start of a season; it is part of the game's design, not a loss or a fault.
Leaderboards show the top 100 players and refresh at regular intervals; weekly and season boards are frozen records and are retained historically.
The only in-app purchase is the one-time Remove Ads entitlement. Payment is handled by Google Play; your payment details never reach the Developer and cannot be seen by the Developer. Purchase, payment, invoicing and refunds are subject to Google Play's own terms, and refund requests must be made through Google Play.
Once the purchase is verified server-side, ads stop from the next match. Verification may take a short while. The entitlement is bound to the profile it was bought on: it follows the profile you keep when accounts are merged (§3.3), but it is not guaranteed to reappear automatically on every device through your Google account — the App offers a restore-purchases path for the same Google account.
Deleting your account does not create a refund and ends the purchased entitlement (§8).
The App shows an interstitial ad between matches and a rewarded "watch an ad for a hint" ad that plays only when you start it. There are no banner ads on the game board and no ads during a match. Ads are served by Google AdMob; in the European Economic Area your consent to personalised advertising is collected through a consent screen and can be withdrawn from Settings. Details are in §5 of the Privacy Policy.
You can delete your account at any time from Settings → Account → Delete account, or request deletion by e-mail through the account deletion page. Deletion is irreversible: sign-in data, display name and username, rating, statistics, achievements and purchase records are deleted; matches you played are retained with a nameless marker because they are also your opponent's history. Details are in §9 of the Privacy Policy.
You may end this agreement at any time by uninstalling the App and/or deleting your account.
The Developer may suspend or close your account if these terms are violated. For less serious violations a lighter measure is applied first (a name reset, a rating correction). If an account is closed, a purchased Remove Ads entitlement also ends; refund requests are directed to Google Play.
The App is provided "as is". The Developer does not undertake that the service will be uninterrupted or error-free; temporary outages may occur because of maintenance, infrastructure failures, interruptions at third-party services (Google Play, AdMob, notification infrastructure) and events of force majeure. Server-side game records are backed up regularly; even so, the possibility of record loss cannot be eliminated entirely.
To the extent permitted by applicable law, the Developer's liability does not extend to the loss of in-game progress, rating, league standing or virtual content. Nothing in these terms limits or excludes the Developer's liability for wilful misconduct or gross negligence, or your rights under consumer protection law.
The App contains no in-game currency, gambling or games of chance; virtual indicators cannot be exchanged for real money.
Changes to these terms are published on this page with an updated effective date; material changes are additionally announced in the App. Continuing to use the App after a change means accepting the current terms.
This agreement is governed by Turkish law. The courts and enforcement offices of İstanbul have jurisdiction; players who are consumers retain their right to apply to the consumer arbitration committees and consumer courts of their own place of residence.
Contact: ikarhan@gmail.com