Privacy

Knowledge Chase / „Обща култура“ · effective 1 November 2026 · Български

The game is made by Angel Georgiev, an individual based in Bulgaria. We keep as little as possible and nothing the game itself does not need.

What is kept and why

• Game progress: levels, points, seen questions, sent duels. It stays on your device, in the browser or app storage. Without an account it never reaches us. With an account we also keep a copy of the levels, points, seen questions and streak on the account, per language. That way you continue on another device where you signed in. No per-question notebook and none of your answers are kept. The copy is deleted with the account.
• Account, optional: a nickname and a password. The password is stored only as an irreversible hash, PBKDF2-SHA256 with a random salt. Nobody can read it, including us. We ask for no phone. The account holds your leaderboard scores: total, weekly, daily, exam, code tournaments. We also keep when you last used it, to the hour, so we know how many accounts are alive.
• A code tournament, if you create one: the code, which account created it, the language and the date. They show "created by" and stop accepting scores after a week. Anyone with the code sees the tournament leaderboard: nickname and points.
• An e-mail on the account, optional. The field on the sign-up form may be left empty and the account is still created. If you leave it empty, the home screen later offers to add one. That is an offer, not a requirement. The address serves mainly one purpose: to give you access back if you forget your password. From the sign-in screen you ask for a link by nickname, and the address receives a one-time link that works for one hour. Besides that, rarely, a few times a year at most, we may write to you about big news in the game itself, for example that an app for your phone is out. If you don't want such e-mails, reply "stop" and we won't write again. We send no ads for anything else and no reminders to it. The daily tournament reminder is separate and asked for separately, see below. It is deleted together with the account.
• Sign in with Google, when available: we keep the technical identifier Google issues for your account, so we recognise you next time, and the e-mail if Google has confirmed it is yours. It serves the same recovery purpose under the same terms as the row above. We do not keep your name or picture from Google.
• Sign in with an e-mail link, if you choose it instead of a password: the address becomes the account's address under the same terms as the rows above. It receives a one-time sign-in link that works for one hour. Until the link is opened we keep with it the nickname you typed and a copy of your progress from the browser you asked from. That way it waits for you wherever you open the link. The copy is deleted as soon as the link is used or expires.
• A random device identifier: 16 random characters created on first launch. It exists only for counting: how many devices opened the game, started a level, finished one. As long as no account has been used on the device, it is linked to nothing and does not say who you are. If you sign in, we keep that this device played with this account. The per-day counters can then be read per account: when you opened the game, played, finished a level or the daily tournament. This covers all days on the device: before you signed in, after you sign out, and when someone else plays on the same device. If you don't want your earlier play linked to the account, sign in from another browser or clear the site's data before signing in. The second also resets the progress on the device. We need it to see how often people with an account come back. For each counter we keep the day and the hour of the first such action that day, to the hour, so we can tell whether a new link works the same afternoon. We keep no answers and nothing finer than that. The link is deleted with the account.
• The kind of device: operating system with version and model as the browser reports them (for example "Android 14, Samsung SM-S911B" or "iOS 17, iPhone"), next to the random identifier above. So we know which phones people play on and where the game breaks. In the app, also its version (for example "1.3.6 (34)"), so we know who needs an update. No serial numbers and nothing that points to you.
• The country: a two-letter code (for example "GB") that Cloudflare derives from the connection's address, in the same row. So we know which countries people play from. We do not keep the address itself, nor a city or anything finer than a country.
• Anonymous counters: which answer was chosen per question for the "Audience" lifeline, flagged questions, duel results by duel code with or without a nickname. No personal identifier beyond the random one above.
• Technical errors in the game: if the game's code crashes, we keep the short technical text of the error, that is message, file, line and game mode, and how many times it happened that day. No identifier. Only the text and the count, so we can fix it.
• Tournament notifications, only in the app and only if you allow them: the notification address your phone gives us (a Firebase token on Android, an Apple token on iPhone), the language, the time zone from the network (for example “America/Chicago”, so notifications don't arrive at night) and, if you are signed in, your account. It carries “your match has started” and “new tournament”. If you remove the app, the address stops working and we delete it. Deleting your account removes the link to it.
• A reminder e-mail address, only if you ask for one after the daily tournament: the address, the language of the letter and a random code for unsubscribing. It is not linked to your account, your progress or the device identifier. It is stored separately and serves the reminder alone. Until you confirm from that inbox, nothing else is ever sent to it.
• A tester e-mail address, only if you enter it yourself on the closed test page at /test-android-en: the address, the language of the page and the label of the link you arrived by. It serves one purpose: adding you to the tester list in Google Play so that Google can send you the invite. We send no letters to this address. It is not linked to an account, to progress or to the device identifier. It is deleted when the closed test ends, or sooner if you ask.
• "Report a problem" reports: your description, an optional screenshot, and technical context: game version, platform, screen size, mode, question, browser user-agent string. They reach the developer as a task on GitHub, in a private repository.

Where it lives and who sees it

• Servers and database run on Cloudflare, Pages and D1, Europe region. Cloudflare sees the technical data of the connection, IP address and requests, as any host does.
• Cloudflare Web Analytics counts visits without cookies and without cross-site tracking.
• Fonts are served from our own server, not from Google Fonts. Nobody else learns anything about you when they load.
• When a new player registers, the developer gets an e-mail via Resend containing the nickname. Nothing else.
• Daily tournament reminders also go through Resend. The company is in the US, our mail is processed in their European region, Ireland. It sees your address because it delivers the mail. We write about the daily tournament and nothing else, no advertising, no third-party offers. The address is not passed on to anyone.
• Notifications to the app go through Google's Firebase Cloud Messaging (Android) or the Apple Push Notification service (iPhone). They see the notification address and the text, because they deliver them.
• Only the developer sees the data. It is not sold, not shared with advertisers, not used for anything outside the game.

Cookies and ads

We set no cookies of our own. The game keeps progress in the device's local storage: localStorage or the app's storage.

Ads may appear in two places, both served by Google: in the Android app through Google AdMob, in the browser through Google AdSense. There are two kinds: a video you choose to watch to get your jokers back in a level, and a small banner on the home screen. There are no ads during a question. When ads are on, Google receives the device's advertising ID (in the app) or sets its own cookies (in the browser) and may use them to pick ads. In the European Union a consent dialog is shown first; without consent the ads are non-personalised. What Google does with the data: policies.google.com/technologies/partner-sites. We only get a count of how many times the video was watched, not who watched it. When ads are off (the default), none of this is loaded.

For how long

• A sign-in session lasts 90 days, then you sign in again.
• A failed sign-in keeps the nickname and the time for one hour — after five of them the nickname waits until the hour is up. A successful sign-in deletes them.
• The account and its scores stay until you delete them.
• Anonymous counters and reports are kept without a time limit. They do not point to a specific person.
• A reminder address is kept until you stop the letters yourself. An address that was requested but never confirmed receives nothing and is used for nothing else.

How to delete

• Account: on the home screen, signed in, "Delete account". It removes the nickname, the password hash, the e-mail if you gave one, sessions and all your leaderboard scores, immediately and irreversibly. Tournaments you created stay for the others who played in them, but no longer point to you.
• Progress on the device: "Choose level" → "Reset progress", or clear the site or app data from your device settings.
• Reminder e-mail: the "stop them" link at the bottom of every letter deletes the address from the database. It does not mark it as stopped, it deletes it.
• Tester e-mail: write to the address below and we remove it at once. Otherwise the whole list is dropped when the closed test ends.
• If something cannot be done from the app, write to the address below and we will delete it by hand. The steps and timelines are on a separate page: Delete your account.

Children

The game is for all ages and collects no data that would tell a child from an adult. There is no chat, no profiles with personal data, no purchases.

Contact

Questions, deletion requests, objections: [email protected].

Changes

If what is kept changes, this page is updated and the date above changes. The history of changes is public in the project repository.