The rules of the house.

These terms apply when you use chessonthemoon.com. By using the site you agree to them, and to the Lunar Laws for how games are played. How we handle your data is in the privacy policy. The legal name of the operator will be published here before launch.

Chess on the Moon is building a robotic chessboard for the lunar surface. The mission is in development and nothing has launched. Every view of the Moon on this site is a digital twin, computed for the reference landing site; it is not live video.

• You can play as a guest or create an account with a passkey. Guests play casual games; rated games need an account.
• Keep your devices secure: whoever holds your passkey can sign in as you. We cannot recover an account if every passkey is lost.
• Choose a handle that doesn’t impersonate anyone and isn’t offensive. We may change or remove handles that break this rule.
• One person, one account for rated play and for voting. Don’t share an account or run several.
• The site is not directed at children under 13, who should not create an account on their own. See the Academy for our schools plan.

Play your own moves. While a game is running you may not use an engine, another person’s advice or any analysis tool, and you may not manipulate ratings, results or votes. The full rules, and how we enforce them, are in the Lunar Laws. We may annul games, adjust ratings and restrict accounts that break them.

Be decent to the people you play and chat with. Don’t:

• harass, threaten or abuse anyone, or post hate, sexual content or spam;
• share anyone’s personal information, including your own if you are young;
• accuse players of cheating in public (use the report button instead);
• try to break, overload or scrape the site, or get around its limits;
• use the site for anything unlawful.

We may hide content and restrict or close accounts that break these rules. Please report what you see.

What you write, such as your bio, chat messages and Founding Crew message, stays yours. You give us permission to store it, show it on the site and use it to run the service, for as long as it is on the site.

Game records (moves, clocks, results and ratings) are facts about public games. We may show them anywhere on the site, broadcast them, and publish them as downloadable files.

Your Founding Crew number shows the order in which you joined. It is a keepsake, not a ticket, share, reward or promise. Signing it does not guarantee that your name or message will be carried to the Moon; if the mission ever carries a record of the crew, what it can hold will be decided then and announced openly.

Everything on the site is free today. There are no entry fees, paid features, prizes or wagering, and no prize depends on a vote or a draw. If we ever run an event with prizes, it will have its own official rules, published before it starts.

We are not affiliated with, or endorsed by, NASA, FIDE or any other space agency, lander company or chess federation. Our ratings are our own, not FIDE ratings. NASA imagery and data used on the site are credited on the credits page and do not imply NASA’s endorsement.

Some illustrations are AI-generated artist’s impressions and are labelled as such. Please keep the label if you share them.

The site uses open-source software under its own licences, including the Stockfish engine under the GNU GPL v3. Those licences, not these terms, govern your rights in that software. Details and source links are on the credits page.

We work hard to keep the site running and the games fair, but we provide it as it is. It may be unavailable, change, or lose data, and features may be added or removed. Ratings, rankings and results can be corrected when we find errors.

Nothing in these terms takes away rights you have under the law where you live.

You can stop using the site at any time and ask us to delete your account (see the privacy policy). We may suspend or close accounts that break these terms. If we change these terms, we will post the new version here with a new date. Which law governs these terms will be set before launch.