Privacy
Updated 31 October 2026.
This notice explains what checkers3d stores, why it is used, what other people can see and how to export or delete your data.
Playing as a guest
Opening the site creates a guest identifier and a session so the same browser returns to the same player. You do not need to supply a name or e-mail to play as a guest.
Account details
An account stores your username, e-mail when supplied, whether it is confirmed, birth year, country, language, creation time and saved settings. The birth year enforces the minimum age of 13 and the protections for people who may be under 16; the full birth date is never requested. Connected sign-in providers have a provider identifier and may supply an e-mail address. These details support sign-in, recovery and your preferences.
Sign-in and security
Passwords are stored as Argon2id hashes, never as readable passwords. An authenticator secret is encrypted; recovery codes and e-mail codes are stored as protected hashes. Sessions store a token digest, creation and last-use times, browser information and an IP address so you can recognise and end access. Short-lived sign-in challenges and rate limits help prevent abuse. Reports, blocks, mutes and moderation records support safety; moderation records can include an IP address.
Country
A two-letter country code may come from the network provider’s CF-IPCountry request header when a player is created. It is an approximate country, not a city or precise location. Contact us if the country is incorrect. Country is used for player information; an IP address is separately stored with sessions for security.
What is public
Usernames, ratings, games, moves, times and results are public. Ratings are grouped by rule set and time category. A public account profile that may belong to someone under 16 exposes only the username and ratings as personal information: no country or joining date. Only accounts certainly 16 or older show their country and the month they joined. No public profile shows an e-mail, birth year or exact sign-up date. Game chat is for the seats, not spectators.
Chat and reports
Stored game chat is normally purged after 30 days. A game’s chat is kept longer while an open report holds it, then becomes eligible for the purge once the report closes. Deletion removes your chat except lines directly identified by an open report, which remain without your account attached. Reports and moderation records can remain after deletion.
Cookies and browser storage
The c3d_session cookie keeps you signed in. It is HttpOnly, so page scripts cannot read it, and is sent over HTTPS. A session expires after 30 days without use and at most 180 days after creation. Short-lived cookies bind provider sign-in and second-factor steps to the browser. Theme, language and board preferences use cookies and browser storage; account settings are also saved on the server. Account, settings and sign-in pages have no advertising cookies or third-party trackers. The pages of finished games load Google AdSense, which may set its own cookies to limit how often an ad repeats, to measure ads and to prevent fraud, even for non-personalised ads; where the law requires it, Google asks for your consent first.
Who handles the data
The hosting and network services process requests; Cloudflare supplies country information when configured in front of the site. A configured e-mail delivery service receives your address and sign-in messages. If you choose a connected sign-in provider, that provider handles its own sign-in. On the pages of finished games, Google AdSense serves the ads: Google then receives your IP address and browser details, as Google's own policies describe. No payment details or advertising profile are collected by these account features.
How long data stays
Accounts and game records have no automatic expiry. Guests older than 180 days are purged only if they have no games and no open report against them. E-mail challenges are purged a day after use or expiry. Session access expires as described above; expired identifiers and token digests can remain until the session list is cleaned or its index expires. Closed accounts, reports, moderation records and the deletion digest described below currently have no automatic purge. Closing an account because its birth year is below the minimum ends access but retains its record for review; it is different from deleting it.
Your choices
Account settings let you change your username; the shell lets you choose the display language; a supplied birth year cannot be changed there. Security settings list sessions and let you sign out one device or every device. Privacy settings download a JSON export of your account, settings, sign-in methods, sessions, ratings, games, your chat and reports, blocks and mutes. The export omits passwords, secret keys and code hashes. Contact us about corrections or data rights that these controls do not cover.
Deletion
Deletion requires your password, a code sent to a confirmed address, or an enabled second factor; if a second factor is on it is required too. With none of these proofs, contact us because settings cannot delete the account. Deletion removes the account, credentials, connected providers, settings, ratings and sessions. Games and moves remain with your seat emptied to preserve opponents’ records. Retained reports and directly reported chat lose their link to you. A hash of a confirmed e-mail remains to prevent an old-site migration from restoring a deleted account. No expiry is currently set for that hash.
Children and teenagers
Accounts require a minimum age of 13. With only a birth year, eligibility and the lifting of under-16 protections wait until the first 1 January when the age is certain. Guests and anyone who may be under 16 have preset chat only and no direct messages. Public profiles omit country and joining month for those accounts. Contact us if you believe an account belongs to a child below the minimum age.
Changes
This draft replaces the former statements that there were no passwords and no stored chat. It also updates session expiry, age protections, export and deletion. If stored data or who can see it changes, this notice and its date will be updated.
Contact
For questions about these pages, your data or an account you cannot delete in settings, write to aleinfoit@gmail.com.