Terms and Conditions

Effective date: 7 August 2026 · Version 2026-08-07

1. Operator and scope

Opening Lab is operated by Felix Hierstetter, Ortrudstr. 4, 81925 München, Germany (“Opening Lab”, “we” or “us”). You can contact us at support@opening-lab.org.

These Terms govern your use of opening-lab.org and the Opening Lab chess-training application. Our Privacy Policy explains how personal data is handled.

2. Eligibility and accounts

You must be at least 18 years old to create or use an Opening Lab account. You must provide accurate registration information, keep your credentials confidential, and notify us promptly if you suspect unauthorized access. Accounts are personal and may not be transferred.

We use an email address for verification, recovery, security, and essential service messages. A public profile, real name, postal address, or payment details are not required for an Opening Lab account.

3. Service and user content

Opening Lab provides tools for building, analyzing, reviewing, and training chess-opening repertoires. You retain ownership of PGNs, repertoires, annotations, reports, and other content you submit. You grant us a limited, non-exclusive license to host, process, copy, and transmit that content only as needed to provide, secure, back up, and improve the service.

You are responsible for ensuring that you have the right to upload and use your content. Chess analysis and suggestions are informational training aids; they do not guarantee playing results or accuracy.

4. Acceptable use

You may not misuse the service, interfere with its security or availability, evade limits, probe or access another person’s account, introduce malicious code, use automated traffic that imposes an unreasonable load, or use Opening Lab in violation of law or third-party rights. Do not use the service to obtain assistance during games where outside help is prohibited.

5. Third-party services

Optional features may connect to Lichess or Chess.com, which operate under their own terms and privacy notices. Funding links open Buy Me a Coffee, whose services are also governed separately. We do not control those third-party services and are not responsible for their availability or independent processing.

6. Free service and voluntary support

Opening Lab is currently provided free of charge. You may voluntarily support the project through Buy Me a Coffee, including optional monthly support. Support provides no feature, access, priority, service, ownership, or other benefit and does not create a paid contract with Opening Lab.

Funding is not a charitable donation and Opening Lab does not issue tax-deductible donation receipts. Payments, recurring-support management, cancellations, and refunds are handled by Buy Me a Coffee and its payment providers under their terms.

7. Availability, changes, and termination

Opening Lab is provided free of charge and without any commitment to a minimum period of availability. We do not guarantee uninterrupted operation, permanent storage, or the continued provision of any feature. We may temporarily suspend or permanently discontinue all or part of the service, including for technical, security, legal, operational, or funding reasons. Where reasonably practicable, we will give advance notice and an opportunity to export account data. A suspension or discontinuation in accordance with this section does not constitute a breach of these Terms. Mandatory legal rights remain unaffected.

You may stop using Opening Lab or delete your account at any time through Account. We may restrict or terminate an account for a material or repeated breach of these Terms, unlawful use, security risk, or operational necessity. Where appropriate, we will give notice and an opportunity to remedy the issue.

8. Liability

To the fullest extent permitted by applicable law, all liability of Opening Lab is excluded. This exclusion does not apply where liability cannot lawfully be excluded or limited, including liability for intent or gross negligence, injury to life, body, or health, claims under the German Product Liability Act, and guarantees expressly assumed. In cases of slight negligence, Opening Lab is liable only for breach of an essential contractual obligation whose performance is necessary for the agreement and on which you may ordinarily rely; liability is then limited to typical, foreseeable damage. In all other cases, liability is excluded. These exclusions and limitations also apply to our legal representatives and agents.

9. Changes to these Terms

We may update these Terms for legal, security, technical, or service changes. We will present material changes in the application and ask account holders to accept the current version before continuing. The version and effective date appear above.

10. Governing law and consumers

German law applies, excluding the UN Convention on Contracts for the International Sale of Goods. If you are a consumer, mandatory protections and available courts in your country of habitual residence remain unaffected. Nothing in these Terms limits statutory consumer rights.

11. Contact

Questions about these Terms can be sent to support@opening-lab.org.