Terms of Use

Last updated: 2026-10-03

These terms apply to the use of Multi Chess, a free browser chess game. The operator is named in the Impressum. How personal data is processed is explained in the privacy policy.

1. The service

Multi Chess is offered free of charge and without advertising. You can play against a chess program that runs in your browser, and against other people in live games and e-mail matches. There is no entitlement to a particular feature or to the availability of the service; features may change. Live games are kept only in the server's memory, so maintenance or a restart can end running live games.

2. Guests and accounts

• You can play without an account. An account is optional and free.
• To create an account you must be at least 16 years old, or have the permission of your parents or legal guardians.
• One account per person. Use an e-mail address that belongs to you and keep your password secret. You are responsible for what happens with your account.
• You can delete your account and all data belonging to it at any time on your account page.

3. Rules of conduct

Please treat other players with respect. In particular it is not allowed to:

• post or send illegal content, insults, harassment, threats, hate speech or sexual content;
• advertise, spam, post links or ask other players for contact details;
• share personal data of other people;
• choose usernames or nicknames that are offensive, misleading or impersonate other people, the operator or the computer opponent;
• use a chess engine, another program or another person's help in games against people. Allowed are only the helpers this website itself offers in relaxed games (move dots, marks for pieces in danger, opening names); strict games have none of them. The coach, hints, analysis and game review are only available against the computer and after a game;
• create several accounts to manipulate games, results or limits, or use bots and automated clients;
• attack or overload the service, try to guess passwords, or test its security without permission (please report vulnerabilities as described in the SECURITY file of the source code).

4. Messages, chat and moderation

The creator of a game decides whether the players can chat, send only predefined quick messages (such as “Good luck!”) or no messages at all. Messages are only visible to the two players of a game, never to spectators.

The chat is not read or moderated by people. An automatic filter refuses messages containing links or web addresses, e-mail addresses, phone numbers, social-media handles and certain threats, replaces severe insults with asterisks, tones down shouting in capital letters and limits how many messages can be sent per minute. Usernames and nicknames with insults or web addresses are refused, too. Such filters make mistakes in both directions; they do not guarantee that every message is harmless.

You stay in control: each player can switch messages off for a game at any time, and you can block a player. Blocked players cannot join your games, you do not see their open games and there are no messages between you. Members can lift a block on their account page; blocks by guests last until the server restarts.

If the operator learns about content or behaviour that violates the law or these terms (for example through a report), the operator may, depending on the severity and in a proportionate way: replace a username, end a game, temporarily restrict access (for example to the public lobby), or delete an account. Affected members are informed by e-mail with the reasons, unless this is not possible or not permitted, and can reply to the contact address in the Impressum. The automatic limits against spam described in the privacy policy apply to everybody in the same way.

5. Reporting illegal content

You can report illegal content (for example a username or a chat message) by e-mail to the contact address in the Impressum. Please include why you consider it illegal, where exactly it is (link of the game, username, date and time), and your name and e-mail address, and confirm that your report is accurate to the best of your knowledge. Reports are handled promptly, carefully and objectively. Please note that chat messages are not archived; a screenshot helps.

6. E-mail matches

E-mail matches are games without a clock in which each player moves whenever they have time. They are available to members only. We send e-mails when it is your turn, when someone accepts your match, before a match is deleted and when it has ended; you can switch these e-mails off on your account page. A match in which nobody moves for 14 days is deleted and does not count in the statistics; the player to move is reminded before.

7. Liability

As the service is provided free of charge, the operator is liable only for intent and gross negligence. This limitation does not apply to injury to life, body or health, or where the law provides for mandatory liability. The operator is not responsible for the content of messages and names chosen by players, but will act on it as described in sections 4 and 5.

8. Open source

The software of Multi Chess is free software under the GNU General Public License version 3 or later. These terms govern the use of this website; they do not restrict the rights the license gives you for the software itself (see Credits & licenses).

9. Changes and final provisions

These terms may be changed when the service or the law changes. The current version is always available on this page with its date. Members are informed about significant changes in good time before they take effect (by e-mail or by a notice on the website) and can delete their account if they do not agree. German law applies; mandatory consumer protection rules of your country of residence remain unaffected. Should a provision be invalid, the remaining provisions remain valid.