Mathematical Trout

What The Game Saves

Mathematical Trout saves aquarium progress in this browser so fish, coins, tanks, pause state, and progress can stay when you come back. It also keeps a cryptographically sealed, last-trusted device backup so accidental damage or a simple direct save edit can be recovered without an internet connection. If you choose an online save, the selected aquarium data and save name are sent to the game database. The password is used to derive the private save key and is not stored.

Public Boards

Publishing is optional. A published aquarium shares its display names, score, coins, fish and koi counts, tank space, and score details. A published bred koi shares its display names, colors, lineage, rarity, and likes. These are visible to other players until removed with the owner's browser token. A live koi market listing also shares the koi's display details, seller nickname, aquarium name, size, traits, and coin price. Private owner tokens and one-time redemption codes are not included in the public listing. Do not use a real full name or put personal information in a display name.

Functional Cookies

The game uses random, signed functional cookies to stop duplicate koi likes, limit abusive cloud-save and public-board requests, and protect monthly koi claims. They do not contain a name, email address, aquarium password, or advertising identifier. These protections are needed for the online game features.

Visit Counting

The site may use Google Analytics to understand traffic and how people use the game only after you allow analytics in the privacy banner. Saying no does not stop the game from working.

Parent PIN And Progress

A parent PIN is optional and stays on this device. The game stores a salted, one-way PIN verifier instead of the PIN itself. The unlocked Parent Center reads local aquarium progress to summarize practice totals, accuracy, grade, recent practice, coins, fish, tanks, and streaks. These parent summaries are not published or sent to Google Analytics. Creating a PIN locks the Parent Center immediately, and refreshing the game locks it again after a parent has unlocked it.

Kids

This game is made for learning. It does not require an account, email address, chat, ads, or selling personal information. Public display names are optional and should not contain personal information.