Terms of Service

Effective November 1, 2026

These terms are the agreement between you and chess.ooo ("we", "us") for using the chess.ooo website and app (the "service"). By creating an account or using the service, you agree to them. If you do not agree, please do not use chess.ooo. Our Privacy Policy explains how we handle your information.

Who can use chess.ooo

You must be at least 13 years old to use chess.ooo. If you are under 18, you need a parent's or guardian's permission, and they agree to these terms for you. Sign-up may be by invitation only while we open the service gradually.

Your account

• Use an email address you control, and keep access to it and to your devices secure. Anyone who can read your email or unlock your passkey can sign in as you.
• One person per account. Do not share your account or sign in as someone else.
• Pick a username and picture that are not offensive and do not impersonate anyone.
• You are responsible for what happens under your account. Tell us at [email protected] if you think someone else has used it.

Fair play and acceptable use

When you use chess.ooo, do not:

• use a chess engine, another person, or any other outside help to choose your moves in a game against another person (analysis, training and games against the computer are of course fine);
• harass, threaten, insult or impersonate other people, or post anything hateful, sexual, violent or otherwise offensive, including in your username, picture, notes, challenge messages and invitations;
• send invitations or friend requests to people who did not ask for them in bulk, or use the invitation system to spam;
• scrape, crawl or copy the service or its data with bots or scripts, or automate your use of it, except through features we provide for that;
• try to break, overload or get around the service's security or limits, probe it for weaknesses, or get into accounts or data that are not yours;
• use chess.ooo for anything illegal, or upload content you do not have the right to share.

If you find a security problem, please report it to [email protected] rather than testing it further.

Your content

Your games, notes, repertoires, profile picture and anything else you add are yours. You give us a worldwide, non-exclusive, royalty-free license to store, copy, process and display that content only as needed to run the service for you: for example, to keep your games, analyze them, show your profile picture to other members, and show a game you share to anyone with its link. This license ends when you delete the content or your account, except for copies in backups, which are deleted on their normal schedule.

You confirm that you have the right to add what you upload. We may remove content that breaks these terms, such as a reported profile picture.

Chess data from others

chess.ooo uses chess information from other sources, including games you import from chess.com and Lichess, opening statistics and position evaluations from Lichess, opening names, and the Lichess puzzle database. That information belongs to its sources and is used under their terms and licenses (see Licenses). We do not control those services and are not responsible for them, their accuracy or their availability. The moves of a chess game are facts that no one owns.

Engine analysis

Evaluations, best moves, move grades, accuracy and explanations come from chess engines and automated tools. They are provided "as is" for learning and entertainment, they can be wrong, and we make no promise that any of it is correct or complete.

Free service and paid features

chess.ooo is free to use today. We may offer paid plans or features in the future. If we do, they will come with their own terms, shown to you before you buy, and nothing will be charged without your agreement. Free features may have usage limits.

Changes to the service

We are building chess.ooo actively. We may add, change or remove features, and the service may sometimes be unavailable for maintenance or because of problems outside our control.

Suspension and ending your account

You can stop using chess.ooo at any time, and ask us to delete your account by writing to [email protected]. We may suspend or close an account that breaks these terms, puts other members or the service at risk, or that we must close by law. Where it is reasonable, we will tell you why. The sections on your content, chess data from others, engine analysis, disclaimers, limitation of liability and governing law continue to apply after an account ends.

Disclaimers

The service is provided "as is" and "as available". To the fullest extent the law allows, we disclaim all warranties, express or implied, including warranties of merchantability, fitness for a particular purpose and non-infringement. We do not promise that the service will be uninterrupted, secure or free of errors, or that your data will never be lost. Keep your own copy of anything important, for example by exporting your repertoires as PGN.

Limitation of liability

To the fullest extent the law allows, chess.ooo will not be liable for any indirect, incidental, special, consequential or punitive damages, or for lost data, profits or goodwill, arising from your use of the service. Our total liability for any claim about the service is limited to the greater of the amount you paid us in the 12 months before the claim or 50 US dollars. Some places do not allow these limits, so they may not all apply to you; nothing in these terms limits rights you have by law that cannot be waived.

Indemnity

If someone brings a claim against us because of content you added or because you broke these terms, you agree to cover our reasonable costs of that claim, to the extent the law allows.

Governing law

These terms are governed by the laws of the State of Ohio, USA, without regard to its conflict of law rules. Any dispute will be handled in the state or federal courts located in Ohio, unless the law where you live gives you the right to bring it in your local courts. Before going to court, please write to us so we can try to sort it out.

Changes to these terms

We may update these terms. We will post the new version here with a new effective date, and for important changes we will tell members in the app or by email before they take effect. If you keep using chess.ooo after a change takes effect, you accept the new terms.

General

If any part of these terms cannot be enforced, the rest still applies. If we do not enforce a part right away, we have not given up the right to do so later. These terms and the Privacy Policy are the whole agreement between you and chess.ooo about the service.

Contact

Questions about these terms, and legal notices: [email protected].