Terms of use

1. A free game and learning tool

GraphDuel offers equation and graph games, practice, daily challenges, learning tools, multiplayer matches, ratings, and profiles. Access is currently free, with no advertising or cash prizes. Using the free service does not authorize future charges. Any future optional purchase will have its own terms presented before payment.

These terms apply to GraphDuel. We ask you to agree before signing in. Our Privacy & Policy page explains personal data; agreeing to these terms does not turn on optional measurement.

2. Accounts and age

You must be at least 16 to create or use an account. By confirming the account declaration and agreeing to these terms, you represent that you meet that requirement. We do not ask for your birthday during sign-in, and Google sign-in does not verify your age for GraphDuel. If you need a parent or guardian to enter this agreement, they must review and agree on your behalf.

Younger players can use practice without an account. No parent-consent account program is currently offered. Do not enter someone else’s age or bypass the account rules. Mandatory local requirements and protections for children still apply.

3. Accounts and visibility

Keep your Google account secure and do not use another person’s account without permission. Choose a nickname instead of your real name, email, school, or address.

Your username, chosen country or region, rating, and game results can be visible to other signed-in players through games and leaderboards. Detailed profile history is private by default; you can choose to share it in profile settings. A friends’ room does not make every related result private.

4. Fair play

Do not cheat, manipulate ratings, impersonate others, harass players, use abusive names, infringe other people’s rights, or disrupt the service. Automated use must not bypass access controls or impair other players’ access.

Use our contact and reports page for abuse, security issues, or moderation questions. We may remove violating content, reset affected results, restrict features, or suspend accounts. We will consider the severity of the issue and provide an explanation and review where appropriate or legally required; urgent protective action may come first.

5. Your submissions

You retain any rights you have in submissions. You give us permission to process, store, and display equations and results as needed to run the game and the features described in the privacy notice. This does not authorize unrelated advertising uses or override privacy rights.

GraphDuel’s software, branding, and artwork may be protected by intellectual-property rights. Third-party materials keep their applicable licenses, including any open-source permissions.

6. Accuracy and availability

Parsers, supported equations, numerical calculations, graphs, and scoring have limits and may contain mistakes. GraphDuel is a game and learning tool; do not rely on it where a mathematical error could cause harm.

We may fix bugs, change scoring, update features, or interrupt service for maintenance or security. We will try to explain significant changes affecting players. We do not promise uninterrupted access or preservation of every result.

Nothing here excludes rights or responsibilities that applicable law makes mandatory, or prevents you from exercising applicable consumer or privacy rights.

7. Stopping and deleting an account

You can stop playing and sign out at any time. Signing out does not delete your account. Privacy controls provides an account export and deletion option. Deletion requires a recent sign-in and finished or abandoned active games. If you cannot sign in or need help, contact us.

Shared scores may remain for opponents under a deleted-player placeholder. Your identifying account details and submitted equations are removed from the live application database. Device storage, provider logs, and backups have separate limits explained in the privacy notice.

8. Changes and questions

We identify the version of these terms above. Material changes will receive appropriate notice and renewed agreement where required. Changes do not remove mandatory rights or retroactively authorize processing that needs another legal basis or consent.

Contact us with questions, complaints, or requests to review an account restriction.