Terms of Service

1. Description of Service

OpenChess is a chess opening training platform that uses spaced repetition algorithms to help players memorize and master their opening repertoire. The service is operated by Yoan Bousquet, based in France.

The Free plan includes up to 2 libraries (4 for accounts opened during the beta), 100 practicable lines per library (accounts opened during the beta keep the levels they unlocked before the beta ended, even beyond that limit), 40 puzzles per library, 20 error cards per library, 7 game reviews per rolling 7-day period, 3 challenges per day and 10 lives in Climb mode. Spaced-repetition reviews are unlimited on every plan.

The Premium plan (Monthly at EUR 6.99/month or Yearly at EUR 59/year) includes up to 20 libraries, unlimited lines, puzzles, error cards and game reviews, unlimited challenges and 30 lives in Climb mode. A founder rate of EUR 39/year instead of EUR 59 is reserved for early subscribers and is kept for as long as the subscription stays active.

2. Account Registration

To use OpenChess, you must create an account by providing a valid email address and username. You are responsible for maintaining the confidentiality of your account credentials.

You must be at least 13 years old to create an account.

You agree to provide accurate and complete information during registration and to keep your account information up to date.

3. Subscriptions and Payments

Premium subscriptions are processed through Paddle.com, which acts as our Merchant of Record. Paddle handles all payment processing, invoicing, sales tax, and VAT on our behalf.

Subscriptions automatically renew at the end of each billing period unless canceled before the renewal date.

Prices are displayed in EUR. Paddle may apply currency conversion for other currencies. All applicable taxes are handled by Paddle.

A full refund can be requested within 14 days of any payment, with no justification required. The full terms are set out in our Refund Policy.

You can cancel your subscription at any time. Upon cancellation, you will retain access to Premium features until the end of your current billing period.

We reserve the right to change subscription prices. Existing subscribers will be notified at least 30 days before any price increase takes effect. The new price will apply to your next billing cycle after the notice period. If you do not agree with the new price, you may cancel your subscription before it takes effect.

Each account is for a single individual only. You may not share your account credentials with others or allow multiple people to use a single account. We reserve the right to terminate accounts that violate this provision.

4. Nature of the Service

OpenChess is a live service platform. Content and features may evolve over time — new features may be added, and existing ones may be modified or removed. Your subscription provides access to the service as it exists at any given time, not to any specific features or content.

We do not guarantee that the service will be available at all times without interruption. Scheduled maintenance and updates may temporarily affect availability.

5. Acceptable Use

You agree not to:

• Use the service for any unlawful purpose

• Attempt to gain unauthorized access to the service or its systems

• Use automated tools, bots, or scrapers to access the service

• Share your account credentials with third parties

• Upload malicious content or interfere with the service's operation

• Reverse engineer, decompile, or disassemble any part of the service

6. Intellectual Property

The OpenChess platform, including its design, code, features, and branding, is the intellectual property of Yoan Bousquet. Chess opening data sourced from public databases (e.g., Lichess) remains in the public domain.

You retain ownership of any personal annotations and notes you create on the platform. By making content public, you grant OpenChess a non-exclusive license to display it to other users.

7. Limitation of Liability

OpenChess is provided "as is" without warranties of any kind. We do not guarantee that the service will be uninterrupted, error-free, or meet your specific requirements.

To the maximum extent permitted by law, OpenChess shall not be liable for any indirect, incidental, special, or consequential damages arising from your use of the service.

8. Termination

We reserve the right to suspend or terminate your account if you violate these Terms of Service. You may delete your account at any time through the account settings page.

Upon account deletion, your personal data will be retained for up to 30 days before permanent deletion, in accordance with our Privacy Policy.

9. Changes to These Terms

We may update these Terms of Service from time to time. We will notify registered users of significant changes via email. Continued use of the service after changes constitutes acceptance of the updated terms.

10. Governing Law

These Terms are governed by the laws of France. Any disputes shall be subject to the exclusive jurisdiction of the courts of France.

For EU consumers: you may also use the European Commission's Online Dispute Resolution platform at https://ec.europa.eu/consumers/odr.

11. General Provisions

These Terms, together with our Privacy Policy and Refund Policy, constitute the entire agreement between you and OpenChess regarding the use of the service.

If any provision of these Terms is found to be unenforceable by a court of competent jurisdiction, the remaining provisions will continue in full force and effect.

Our failure to enforce any provision of these Terms shall not constitute a waiver of that provision or any other provision.

We may assign or transfer our rights and obligations under these Terms without prior notice. You may not assign or transfer your rights without our written consent.

12. Contact

For any questions about these Terms of Service, please contact us at: