Terms of Service

Acceptance of Terms

By accessing or using Sudoku Challenge (sudokuchallenge.com), you agree to be bound by these Terms of Service ("Terms"). If you do not agree, you may not use the platform. These Terms constitute a legally binding agreement between you and Sudoku Challenge ("we", "us", "our").

We may update these Terms from time to time. Continued use of the platform after changes constitutes acceptance of the revised Terms. Material changes will be communicated via a notice on the platform.

Description of Service

Sudoku Challenge is a free-to-play online Sudoku platform offering Classic and Killer Sudoku across five difficulty tiers, daily challenges, tournaments, duels, a puzzle solver, and a Learning Hub. The platform is built on the Internet Computer Protocol (ICP), a decentralized blockchain network. Additional premium features are available through a paid subscription.

Accounts & Authentication

You may use Sudoku Challenge as a guest (with limited features) or by authenticating through Internet Identity, a decentralized authentication system. When creating an account:

• You must choose a username that complies with our Username Policy (no offensive, hateful, or inappropriate content).
• You are responsible for maintaining the security of your Internet Identity credentials.
• You must not impersonate other users, staff, or public figures.
• We reserve the right to suspend or terminate accounts that violate these Terms.
• Guest accounts are temporary and may be lost when browser data is cleared.

Acceptable Use

You agree to use Sudoku Challenge in compliance with all applicable laws and these Terms. You must not:

• Use automated tools, bots, scripts, or any software to gain an unfair advantage in puzzles, tournaments, or duels.
• Exploit bugs, vulnerabilities, or unintended features in the platform.
• Manipulate ratings, scores, or leaderboards through any dishonest means (including multi-accounting).
• Harass, abuse, threaten, or intimidate other users through usernames, feedback, or any platform feature.
• Submit content that is unlawful, defamatory, obscene, hateful, or discriminatory.
• Attempt to access other users' accounts or data without authorization.
• Interfere with the platform's operation, including denial-of-service attacks or tampering with the platform's smart contracts.
• Use the platform for any commercial purpose without our written consent.

Violations may result in warnings, temporary suspension, permanent ban, or rating/score reset, at our sole discretion. See our Fair Play Policy for detailed anti-cheating rules.

Premium Subscription

Sudoku Challenge offers a Premium subscription with the following terms:

• Pricing: Subscription fees are displayed at the time of purchase and vary by currency/region. All prices include applicable taxes where required.
• Billing Cycle: Subscriptions are billed monthly (or annually if selected). Your payment method will be automatically charged at the beginning of each billing period.
• Free Trial: If offered, free trials automatically convert to paid subscriptions unless cancelled before the trial period ends.
• Cancellation: You may cancel your subscription at any time through your account settings. Cancellation takes effect at the end of the current billing period — you retain Premium access until then.
• Refunds: We generally do not provide refunds for partial billing periods. If you experience a technical issue that prevents you from using Premium features, contact us within 7 days for a resolution.
• Price Changes: We may change subscription prices with 30 days' notice. Existing subscribers are notified before the new price takes effect.
• Payment Processing: All payments are processed by Stripe, Inc. By subscribing, you also agree to Stripe's Terms of Service.

© Intellectual Property

All content on Sudoku Challenge — including the website design, code, graphics, icons, logos, on-screen elements, puzzle generation algorithms, and text — is owned by Sudoku Challenge and protected by copyright and intellectual property laws. You may not reproduce, distribute, modify, or create derivative works without our written permission.

Sudoku puzzles generated by the platform are provided for personal, non-commercial use only. The underlying puzzle generation technology and scoring systems are proprietary.

User-Generated Content

When you submit content to the platform (such as feedback, reviews, or usernames), you grant Sudoku Challenge a non-exclusive, worldwide, royalty-free license to use, display, and distribute that content in connection with operating the platform. You represent that you have the right to submit such content and that it does not violate any third-party rights or these Terms.

We reserve the right to remove any user-generated content that violates these Terms, without notice.

Tournaments & Competitions

• Tournaments and duels are governed by the rules displayed on the platform at the time of the event.
• We reserve the right to void results, adjust scores, or disqualify participants who violate fair play rules.
• Rating adjustments due to anti-cheat enforcement are final.
• Tournament scheduling, format, and availability may change without prior notice.

Disclaimers

Sudoku Challenge is provided "as is" and "as available" without warranties of any kind, express or implied. We do not guarantee that:

• The platform will be uninterrupted, error-free, or secure at all times.
• Game data stored on the blockchain will be accessible indefinitely (though we make reasonable efforts to maintain it).
• Ratings, scores, or leaderboard positions are perfectly accurate in every unusual case.

To the maximum extent permitted by law, we disclaim all warranties including merchantability, fitness for a particular purpose, and non-infringement.

Limitation of Liability

To the maximum extent permitted by applicable law, Sudoku Challenge and its operators shall not be liable for any indirect, incidental, special, consequential, or punitive damages arising from your use of the platform. Our total liability for any claim shall not exceed the amount you paid to us in the twelve (12) months preceding the claim, or AUD $50, whichever is greater.

Some jurisdictions do not allow the exclusion of certain warranties or limitation of liability, so the above limitations may not apply to you in full.

Governing Law

These Terms are governed by the laws of New South Wales, Australia, without regard to conflict of law provisions. Any disputes arising from these Terms shall be resolved in the courts of New South Wales, Australia. Notwithstanding the foregoing, we reserve the right to seek injunctive relief in any jurisdiction.

Termination

We may suspend or terminate your access to Sudoku Challenge at any time, with or without cause, with or without notice. Upon termination, your right to use the platform ceases immediately. Provisions that by their nature should survive termination (including intellectual property, disclaimers, limitation of liability, and governing law) shall survive.

You may stop using the platform at any time. If you have a Premium subscription, cancellation of your account does not automatically cancel your subscription — please cancel your subscription first through account settings.

Questions?

If you have questions about these Terms of Service, please contact us.