Terms of Service

Last updated 10 Oct 2026 · Also available in Español.

1. About these terms

These terms are an agreement between you and Nicolas Carnevale, Argentina ("we", "us"), who runs Out of Book at outofbookchess.com. By creating an account you accept them and our Privacy Policy. If you don't agree, don't use the service.

You must be at least 13 years old. In the EU/EEA you must also be old enough to consent to online services in your country (up to 16), unless a parent or guardian agrees.

2. The service

Out of Book helps you study chess openings. You can:

  • build repertoires on the board or import them from PGN, and export them again;
  • practice them with spaced repetition;
  • analyse positions with a chess engine that runs in your browser;
  • compare your own games from Chess.com, Lichess and over-the-board tournaments with your repertoire, and practice where you went wrong.

The service is free. It has limits on how much you can store, shown in the app when you reach them. Today they are: games from up to 3 years before the day you choose how far back to load, 5 linked accounts, 50 repertoires, 20,000 moves per repertoire and 50,000 games. We may change the limits; lowering one never deletes what you already have.

We may change, add or remove features.

3. Your account

  • You sign in with your email and a password, or with Google. You must confirm your email address.
  • One account per person. Keep your sign-in details secret: you're responsible for what happens under your account.
  • If you think someone else got into your account, sign out the other devices under Account → Signed-in devices, change your password, and write to support@outofbookchess.com.

4. Linking Chess.com, Lichess and FIDE

  • Only link accounts that are yours. Chess.com accounts are checked with a code in your profile, and Lichess accounts by signing in to Lichess. A FIDE ID isn't checked, so only enter your own.
  • By linking an account you ask us to fetch your games from that site for you. Its own terms keep applying to you.
  • We are not affiliated with or endorsed by Chess.com, Lichess or FIDE. Chess.com is a trademark of Chess.com, LLC.
  • These sites can change or stop their services at any time. Importing games may then stop working, and we aren't responsible for that.

5. Your content

  • Your repertoires, notes and the files you upload stay yours.
  • You give us a worldwide, non-exclusive, free licence to store, copy and process that content only to run the service for you, including backups. The licence ends when you delete the content or your account, apart from backups that expire on their normal schedule.
  • Only upload what you have the right to use. That includes PGN files from other sites or authors, such as tournament sites and paid courses, whose terms may restrict copying. Don't upload anything unlawful or anything that infringes someone else's rights.
  • We may remove content that breaks these terms.

6. Acceptable use

Don't:

  • use the app or its engine to get help during a game you are playing, online or over the board;
  • send automated requests to the service, scrape it, or call its endpoints outside the app, including to trigger game syncs;
  • try to get around the limits, reach other users' data, or probe or attack the service;
  • link accounts that aren't yours, or use the service to harass anyone;
  • resell or redistribute the service.

We may suspend or close accounts that break these rules. Where it's reasonable, we will warn you first.

7. The chess engine

The chess engine is Stockfish (stockfish.js 19), free software under the GNU General Public License v3 (opens in a new tab). Its source code is on GitHub (opens in a new tab). Nothing in these terms limits your rights under that licence.

8. Supporting Out of Book on Patreon

  • Support on Patreon is voluntary. It is a contribution to the project's development, not a purchase: it unlocks no features, limits or priority in the app, which is the same for everyone.
  • You pay Patreon, under Patreon's terms. Patreon processes the payment and handles cancellations and refunds; we never see your card details.

9. Availability and changes

We try to keep the service running, but we don't promise it will be uninterrupted or free of errors. We may stop the service. If we do, we will give you at least 30 days' notice and a way to export your data.

10. Disclaimer

  • The service is provided "as is".
  • Engine evaluations, opening names and game analysis may contain mistakes.
  • We don't promise any result in your chess.
  • Keep your own copies of important repertoires: you can export them at any time.

11. Liability

To the extent the law allows, we aren't liable for indirect or consequential losses, and our total liability is limited to USD 50, since the service is free. Nothing here limits liability that can't be limited by law, or your rights as a consumer.

12. Ending

  • You can delete your account at any time under Account → Delete account. That deletes your data as the Privacy Policy describes.
  • We may end these terms if you seriously or repeatedly break them.
  • Sections 5 (the licence until deletion), 10, 11 and 13 survive.

13. Law and disputes

  • These terms are governed by the laws of Argentina, and the courts of Argentina have jurisdiction.
  • If you are a consumer, you keep the mandatory protections of the country where you live, and you may go to your local courts.

14. Changes to these terms

We will post changes here and update the date at the top. For important changes we will email you at least 30 days before they apply. If you keep using the service after that, you accept them; if you don't agree, you can delete your account.

15. Languages

These terms are available in English and Spanish. Both versions are equally valid.

16. Contact

support@outofbookchess.com