Legal notice, privacy & league rules

Legal notice (mentions légales)

Publisher: ChessX, the chess committee of the École Polytechnique Bachelor Program, a student committee at École Polytechnique, Route de Saclay, 91128 Palaiseau, France. Contact: through the committee’s Telegram group or any committee member.

Hosting: Vercel Inc., 440 N Barranca Ave #4133, Covina, CA 91723, USA (website). Database and authentication: Supabase Inc., 970 Toa Payoh North #07-04, Singapore 318992, with data stored in the European Union (AWS eu-west-1, Ireland).

Intellectual property: the site, its code, texts and the “ChessX” name are the property of the publisher and protected by copyright (Code de la propriété intellectuelle). Chess puzzles are provided by lichess.org under their open licence. Online games are played on lichess.org and chess.com, which are independent services with their own terms.

Privacy (GDPR)

What we store: your @polytechnique.edu email and password (hashed), display name, promo, your Polytechnique Elo and its history, games played in committee events, puzzles solved, event RSVPs and league sign-ups, and — only if you link them yourself — your Lichess and chess.com usernames. We do not use advertising or tracking cookies; the only cookie keeps you logged in.

Why: to run the committee’s activities (events, rankings, league, online play) — our legitimate interest as a student association and the service you asked for by creating an account. Emails about events are sent only to members who keep them enabled on their profile; every email has an unsubscribe link.

Who sees what: your name is visible to logged-in members. Your rating appears on the public ranking only if you opt in on your profile and have played at least 5 rated games. Emails are visible to committee admins only. Data is not sold or shared with third parties, except the processors named above (Vercel, Supabase, and Resend Inc. for sending emails).

Your rights: you can read and change your data on your profile, unlink Lichess/chess.com at any time, and turn off event emails. To delete your account and data, or to exercise any other right (access, rectification, portability, objection), contact the publisher; we answer within a month. Game records may be kept in anonymised form so that other members’ ratings stay consistent. You can also complain to the CNIL (cnil.fr).

Retention: as long as your account exists, and at most one year after you leave the Bachelor Program.

Rules of play

Membership is reserved to students with an @polytechnique.edu address. Ratings are updated only by games verified by the platform (Lichess / chess.com) or confirmed by both players or a committee admin; results confirmed by both players are final unless an admin corrects an obvious error. Cheating (engine use, playing under someone else’s account) leads to removal from rankings and events. Admins may adjust a rating in exceptional cases; every adjustment is logged with a reason. Be kind at the board and online.