Please read these terms carefully before using Sudoku Challenge. Effective 14 February 2026.
By accessing or using Sudoku Challenge (sudokuchallenge.com), you agree to be bound by these Terms of Service. If you do not agree, you may not use the platform. These Terms constitute a legally binding agreement between you and Sudoku Challenge. We may update them from time to time; continued use after changes constitutes acceptance of the revised Terms.
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.
You may use Sudoku Challenge as a guest (with limited features) or by authenticating through Internet Identity. When creating an account, you must choose a username that complies with our Username Policy, keep your Internet Identity credentials secure, and not impersonate others. 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.
You agree to use the platform lawfully and in compliance with these Terms. You must not use bots, scripts, or automated tools to gain an unfair advantage; exploit bugs or vulnerabilities; manipulate ratings, scores, or leaderboards (including multi-accounting); harass or abuse other users; submit unlawful, defamatory, obscene, hateful, or discriminatory content; access other users' accounts without authorization; interfere with the platform's operation; or use it for commercial purposes without written consent. Violations may result in warnings, suspension, permanent ban, or rating/score reset. See our Fair Play Policy for detailed anti-cheating rules.
Premium subscription fees are displayed at purchase and vary by region. Subscriptions bill monthly (or annually if selected) and renew automatically until cancelled. You may cancel at any time in account settings; cancellation takes effect at the end of the current billing period, and you keep Premium access until then. We generally do not refund partial periods. Prices may change with 30 days' notice. All payments are processed by Stripe, Inc.; by subscribing you also agree to Stripe's Terms of Service.
All content on Sudoku Challenge — website design, code, graphics, icons, logos, UI components, 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 written permission. Puzzles are provided for personal, non-commercial use only.
When you submit content (feedback, reviews, or usernames), you grant Sudoku Challenge a non-exclusive, worldwide, royalty-free license to use, display, and distribute it in connection with operating the platform. You represent that you have the right to submit such content and that it does not violate third-party rights or these Terms. We may remove any content that violates these Terms without notice.
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.
Sudoku Challenge is provided "as is" and "as available" without warranties of any kind. We do not guarantee uninterrupted, error-free, or perfectly secure operation, indefinite blockchain data availability, or flawless ratings in all edge cases. To the maximum extent permitted by law, we disclaim all warranties and are not liable for indirect, incidental, special, consequential, or punitive damages; our total liability for any claim shall not exceed the amount you paid us in the preceding twelve months, or AUD $50, whichever is greater.
These Terms are governed by the laws of New South Wales, Australia. We may suspend or terminate your access at any time, with or without cause or notice; provisions that by their nature should survive termination (intellectual property, disclaimers, limitation of liability, governing law) will survive. You may stop using the platform at any time; if you have a Premium subscription, cancel it through account settings first.
If you have questions about these Terms, contact us at support@sudokuchallenge.com.