Privacy policy

This English version is a courtesy translation. Only the German version is legally binding.

Thank you for your interest in nummix. Protecting your personal data matters to us. Here we explain which data is processed when you visit this website and when you play at play.nummix.de, for what purpose and on which legal basis.

1. Controller

The controller within the meaning of the General Data Protection Regulation (GDPR) is:

We are not required to appoint a data protection officer.

2. The essentials in brief

• We use no cookies and no analytics or tracking tools. That is why there is no cookie banner.
• Only if you switch between the light and dark design yourself does your browser remember that choice (see section 5).
• Fonts, images and all other files are stored on our own web space. No data is sent to third parties such as Google when you open a page.
• We only process technically necessary access data (with a shortened IP address, deleted after 7 days) and the data you send us yourself by email.
• Additional information for the online game play.nummix.de is in section 10, on the use of AI see section 11.

3. Hosting and server log files

This website is hosted by Hetzner Online GmbH, Industriestr. 25, 91710 Gunzenhausen, Germany. The servers are located in data centres within the European Union; no data is transferred to countries outside the EU or EEA.

When you open the website, the server automatically stores access data in so-called log files:

• shortened IP address (the last block is replaced by a random value, so it cannot be traced back to you)
• date and time of access
• page or file requested and amount of data transferred
• website from which you came (referrer URL)
• browser and operating system used, and HTTP status code

This data is processed to deliver the website and to keep it running securely and without errors. The legal basis is Art. 6 (1) (f) GDPR; our legitimate interest lies in the stable and secure operation of the website. The log files are deleted automatically after 7 days.

We have concluded a data processing agreement with Hetzner pursuant to Art. 28 GDPR.

4. Encryption

For security reasons, this website uses TLS encryption. You can recognise an encrypted connection by “https://” in the address bar and the padlock symbol in your browser.

5. Storage on your device

If you switch between the light and dark design at the top of the page, your browser stores your choice in its local storage (“localStorage”) under the name nummix-theme. The entry contains only “light” or “dark”, is not sent to us or to third parties, and remains until you delete it in your browser. If you do not switch, nothing is stored.

This storage is strictly necessary to provide the function you have expressly requested and is therefore permitted without consent under § 25 (2) no. 2 TDDDG (German Telecommunications Digital Services Data Protection Act).

6. Contact by email

If you write to us by email, we process your email address, the content of your message and, if you give it, your name in order to answer your enquiry.

The legal basis is Art. 6 (1) (b) GDPR if your enquiry relates to a contract or steps prior to entering into one, such as a request for a game set. In all other cases the legal basis is Art. 6 (1) (f) GDPR; our legitimate interest lies in answering enquiries.

We delete your data once your enquiry has been fully dealt with, unless statutory retention obligations (for example under commercial or tax law) prevent this. Emails are received and stored by united-domains GmbH, Gautinger Straße 10, 82319 Starnberg, Germany, with whom we have also concluded a data processing agreement.

Contact form

If you use the contact form on this website, your message is sent directly to the server of our online game play.nummix.de, which we operate ourselves, and stored there. We process your email address, your topic (e.g. “Question” or “Idea”), your message, your name if you give it, as well as the page language, your browser’s identifier and the country derived from your IP address. We do not store the IP address itself; it is only kept briefly in memory to limit mass messages (at most five per hour).

We use this data solely to handle your enquiry and reply to you. The legal bases are the same as for email above. We automatically remove your name and email address no later than six months after receipt, or immediately on request. We keep the message itself without any link to you if it helps us improve nummix.

List of honored testers

On the “About” page your browser loads the current list of honored testers (public player names) from our own server play.nummix.de. As with every page request, your IP address is processed technically; no cookies are set and no data about you is stored. Without JavaScript you see the fixed list. Legal basis is Art. 6(1)(f) GDPR; our legitimate interest is keeping the list up to date.

The list shows the first 42 accounts that played on play.nummix.de – only with a public profile that is also visible under “Players”, and not suspended. If you do not want to be listed, turn off “Visible under Players”, set your profile to private or write to us.

Ordering a game set

We sell the game set through our shop on Ko-fi (ko-fi.com, a separate provider with its own privacy policy); payment is made there via the payment services Ko-fi offers. When you order, Ko-fi sends us your name, email address, shipping address, the items ordered and the amount. We use this data to ship your order and to answer questions about it. For shipping, we pass your name and shipping address to the delivery company we use. The legal basis is Art. 6(1)(b) GDPR (contract). Orders do not count as donations and are never shown publicly. Records we must keep under commercial and tax law are retained for up to ten years; everything else is deleted once the order is complete.

7. Recipients of your data

Your data is only received by the hosting and email providers named above as processors, our AI assistant (section 11), the delivery company if you place an order, and, where required by law, by public authorities. We do not sell data and do not pass it on for advertising purposes.

8. Your rights

You have the following rights regarding the personal data concerning you:

• right of access (Art. 15 GDPR)
• right to rectification (Art. 16 GDPR)
• right to erasure (Art. 17 GDPR)
• right to restriction of processing (Art. 18 GDPR)
• right to data portability (Art. 20 GDPR)
• right to withdraw consent at any time with effect for the future (Art. 7 (3) GDPR)

To exercise your rights, an informal message to info@nummix.de is enough.

Right to object under Art. 21 GDPR

Where we process data on the basis of Art. 6 (1) (f) GDPR, you may object to this processing at any time on grounds relating to your particular situation. We will then no longer process the data unless we can demonstrate compelling legitimate grounds that override your interests, or the processing serves the establishment, exercise or defence of legal claims.

Right to lodge a complaint with a supervisory authority

You have the right to lodge a complaint with a data protection supervisory authority (Art. 77 GDPR), in particular in the member state of your habitual residence, your place of work or the place of the alleged infringement. The authority responsible for us is the State Commissioner for Data Protection and Freedom of Information of the Free Hanseatic City of Bremen, Arndtstraße 1, 27570 Bremerhaven, Germany.

9. Obligation to provide data and automated decision-making

You are not obliged to provide us with personal data. Without the technical access data, however, the website cannot be delivered, and without an email address we cannot reply to you. There is no automated decision-making, including profiling, under Art. 22 GDPR on this website; for the auto-moderator in the online game see section 10.9.

10. Playing online at play.nummix.de

At play.nummix.de you can play nummix in your browser – as a guest without signing in or with a free account. This involves more data than this website. Here is which data, for what purpose and for how long. The controller is the same as in section 1; your rights from section 8 apply here too.

10.1 The essentials in brief

• No tracking, no ads, no analytics tools, no in-game purchases.
• A single cookie: your sign-in, if you use an account (technically necessary).
• You can play without an account. For an account we need a username and an email address.
• An auto-moderator checks chats and names against a word list; the nummix team can view chats for moderation.
• You can delete your account yourself at any time (14-day grace period).

10.2 Server and hosting

play.nummix.de runs on a server we operate ourselves – currently on our own premises in Bremen (address in section 1). A move to a data centre of Hetzner Online GmbH in Germany is planned; a data processing agreement with Hetzner is in place. We also run our mail server ourselves. The proxy in front of the game does not store access logs. Data is only transferred to countries outside the EU for push notifications (10.10) and when we use our AI assistant (section 11).

10.3 Connection data

While you play, your browser keeps a connection to the server open. We process your IP address, your browser identifier (user agent) and the times of your actions – to protect against overload and abuse (limits on connections, new games and messages per IP address) and for the flag next to your name. We derive the country from the IP address with a database on our own server (DB-IP “IP to Country Lite”); the IP address does not leave the server for this. You can switch the flag off in the lobby.

For troubleshooting and abuse protection, administrators see for each connection its start and end, IP address, country, account (if signed in), browser identifier, technical device details (screen and window size, pixel density, language, theme, version, installed app), visited areas, game codes and the number of messages. We delete this connection data after 30 days. The legal basis is Art. 6 (1) (f) GDPR (safe, fair gameplay), for accounts also (b).

Sign-in protection: we count failed sign-in attempts per IP address for 15 minutes – only in the server’s memory, without reference to an account. After five failed attempts your browser has to solve a short computation before each further attempt (no picture puzzle, no third-party service); after ten, password sign-in from this IP address is blocked for 15 minutes. The legal basis is Art. 6 (1) (f) GDPR (protecting accounts against takeover).

10.4 Playing as a guest

As a guest we process the name you choose in the lobby (or a random one), your moves, points and chat messages. Finished games are stored (result, game history, replay); your name appears there as you chose it. So that you can take over your games after registering, we store a non-reversible check value for your seat.

10.5 Account

If you create an account, we process:

• username and email address (required), your password only as a secure hash and/or passkeys (only the public key),
• with two-factor sign-in, the secret key for the authenticator app (encrypted) and the recovery codes (only as hashes),
• optional details: display name, profile text, profile picture, player colour, team and groups (for teams and groups also a chosen emoji, a colour or a crest image; founders upload it, it is scaled down and stripped of metadata),
• game data: games, points, Nummix Score, level, achievements, friendships, invitations, blocks,
• sign-in sessions with browser identifier (so you can recognise your devices), valid for 30 days.

Visibility: username, display name, profile picture, profile text, team, statistics, achievements and recent games are visible to others; name and points appear in the leaderboard and – for public games – on the live page. Others see whether you are online unless you switch this off in your profile. With “private profile”, only friends see details. Other signed-in members find you in the member list and can invite you to games; you set “Invitations from non-friends” (on by default) and “Open to random games” (off by default) in your profile. If you support nummix with a donation linked to your account (10.7), we show a flame ring around your profile picture in the month of the donation.

Email address: we use it to confirm your account, for game invitations (if you are not online or do not react within two minutes; at most five such emails a day; by default only for invitations from friends – under “Invitation emails” you can choose “from everyone” or “never”), for replies to your feedback, for security notices (when your address, password, passkeys or two-factor sign-in change, or someone tries to create another account with your address) and for notices about deleting your account. No newsletter, no advertising.

The legal basis is Art. 6 (1) (b) GDPR (providing the account and game features). nummix is meant for all ages. If you are under 16, please only create an account with your parents’ consent. If you voluntarily tick “I am under 16” when registering, we only set your privacy settings to be more protective (private profile, not findable, online status off, invitations only from friends, no random games); we do not store your age (Art. 25 GDPR).

10.6 Storage on your device

Cookie: when you are signed in, we set the cookie nmx_session (random identifier of your sign-in, HttpOnly, 30 days). Without signing in we set no cookie.

Local storage (localStorage) – stays in your browser until you delete it: language, theme and view settings; whether news and the storage notice have been seen; your name for guest games and whether the flag is shown; seat identifiers so you can return to your game after reloading; games against the computer in the browser; your progress in the tutorial and quiz; whether we may ask you about notifications and whether you confirmed the age consent when switching them on; a random device identifier, used only for auto-moderator warnings for guests (10.9). The browser also keeps a cache (service worker) of the program files so the game loads quickly.

We serve fonts and icons ourselves; no files are loaded from third parties. All entries are necessary for the features you use (Section 25 (2) no. 2 TDDDG). That is why we do not ask for consent but only show a short notice on your first visit with a link here.

10.7 Donations

At play.nummix.de/spenden you can support nummix via Ko-fi (ko-fi.com, a separate provider with its own privacy policy) or by bank transfer. Ko-fi notifies us of every donation automatically: name, amount, currency, message, whether the donation may be public, whether it is a subscription, time and transaction number. We only compare the email address Ko-fi sends with confirmed addresses of nummix accounts to link the donation to your profile (Hall of Fame with profile picture, achievement, flame ring); it is not stored. We enter bank transfers by hand. Your name appears in the Hall of Fame only if the donation may be public. We only show the bank details on click. We keep donation records as long as they are needed as proof (at most ten years); on request we unlink them from your account or remove your name from the Hall of Fame.

10.8 Chat

Chat messages are stored with name, time and game and are visible to the players (and, depending on the host’s settings, to spectators). Administrators can view the chats of all games, including private ones, to check reports and violations. We delete chat messages after twelve months.

10.9 Moderation and reports

To keep nummix pleasant for everyone – including children and young people – an auto-moderator checks every chat message and every name against a word list for insults and content unsuitable for minors (no AI). If it matches, the message is not sent and you receive a warning. After repeated violations we block automatically: guests after ten warnings (via the device identifier, in exceptional cases for 24 hours via the IP address), accounts after ten warnings for 24 hours and then for seven days. Blocked people can watch but not play or write.

For each case we store the blocked text, the detected terms, name or account, IP address or device identifier and the preceding chat messages as context. Whoever reports another person also sends the reason, an optional description and the latest chat messages. Administrators review the cases and can impose or lift blocks. If you think a decision of the auto-moderator was wrong, write to us – we will review it in person (Art. 22 (3) GDPR).

We delete the IP address, device identifier, chat excerpt and text of a case after 90 days (the case itself remains without these details to recognise repeated violations); warnings of guests without an active block after 90 days. The legal basis is Art. 6 (1) (f) GDPR – protecting players from insults and unsuitable content.

10.10 Push notifications

If you switch on notifications (e.g. “It’s your turn” or “Your game is starting”), we store your browser’s push address. Notifications are delivered via your browser vendor’s push service (e.g. Google, Apple or Mozilla), which receives the push address and the encrypted content; this may involve a transfer to the USA. You can switch push off at any time in your profile or browser settings. The legal basis is your consent (Art. 6 (1) (a) GDPR), which you can withdraw at any time. If you are under 16, you need your parents’ consent for this (Art. 8 GDPR). That is why we ask once when you first switch it on on a device; only the fact that we asked is stored in your browser – not your age.

10.11 Feedback and contact form

We store feedback and ratings with the text, optionally your contact details and technical information (page, screen size, language, browser identifier, possibly game and players) to be able to trace errors. If you are signed in, we see your account and can reply in your profile and by email. We delete contact details and browser identifier after twelve months. Signed-in users reporting a problem can voluntarily attach up to two screenshots; they are scaled down in the browser, stripped of metadata on the server, visible only to the nummix team (not to our AI assistant either) and deleted after 180 days at the latest or when your account is deleted. Messages from this website’s contact form also end up here (see section 6).

10.12 Deleting your account

Under “Edit profile → Delete account” you can delete your account yourself. It is finally deleted after 14 days; until then your profile is invisible and you can cancel the deletion by signing in. We send you a confirmation, a reminder 48 hours before and a last email after deletion. On deletion we remove sign-in data, passkeys, friendships, invitations, achievements, push subscriptions and team and group memberships; in past games, replays, the tournament archive and chat you then appear as “Deleted account” so that the results of others are preserved.

Unconfirmed accounts: if an account’s email address is still not confirmed 60 days after signing up and no game was played with it, we delete the account. We send a reminder to the address 14 days before; if you confirm it or play a game, the account stays. We never delete confirmed accounts on our own.

10.13 Further retention periods

• Expired sign-in sessions and email links: immediately after expiry.
• Invitations: 30 days.
• Connection data for the admin overview: 30 days.
• Games, results, replays, tournament archive: as long as the game is offered or until account deletion (then without reference to you).
• Backups: the database is backed up daily – encrypted (borg with a passphrase) on storage we run ourselves. We delete backups after one year. Deleted data may still be contained in older backups until then; we only use them to restore operation after an outage.

10.14 Recipients

Your data is only received by the nummix team (administrators), for push the browser vendors’ push services, our AI assistant (section 11) and, where required by law, authorities. We do not sell data or pass it on for advertising.

11. Use of AI

Transparency matters to us: nummix is developed and operated with the help of the AI assistant Claude by Anthropic PBC (San Francisco, USA). Claude writes and reviews program code for play.nummix.de and this website, drafts texts and translations and helps with maintenance and troubleshooting. People from the nummix team decide what gets published. More on the Fair play page.

Claude works on our server and in individual cases also sees personal data – for example the text of your feedback or a contact message, usernames, names from donations or entries from error logs. This content is transferred to Anthropic for processing, including to the USA. We currently use Claude through a subscription for individuals (Claude Pro/Max). Anthropic’s consumer terms apply to it; there is no data processing agreement. We are therefore switching to a business account with a data processing agreement and, until then, take particular care to show Claude personal data only where the task makes it unavoidable. We only give Claude what the task at hand needs. The legal basis is Art. 6 (1) (f) GDPR; our legitimate interest is being able to develop and run nummix as a small, non-commercial project.

No AI makes decisions in the game itself: the computer opponent follows fixed rules, the auto-moderator works with a word list.

12. Changes to this privacy policy

We update this privacy policy when the website, the online game or the legal requirements change. The version published here applies.

Last updated: October 2026

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