About

Last updated: 16/10/2026

Why this page exists

Everyone knows Bau Cua Tom Ca, yet a chance to play it together is rare, because it takes enough people sitting around one tray. This site rebuilds that very tray on the web: a board with six squares, a dice bowl in the middle, and the whole room picking a square in the same round — swapping coins for virtual points so nobody risks real money.

Why it is free

The site runs on server costs, and is funded by ads shown at the edges of the page (never around the game board, so you do not tap them by mistake). Ads do not affect the dice result, and you pay nothing to play. If you see an ad placed badly, tell us.

What virtual points are

Everyone who joins the room is given a small amount of points to start. Points are used to pick squares, move up and down across rounds, and climb the room leaderboard. Points are not real money: not bought or sold, not transferred, and not convertible into money or gifts. So you can play at ease without worrying about losing anything. See details in the Terms of use.

What is in the room

• Six-square board just like playing in person, with the dice bowl shaking in the middle. Two "rabbit ears" flank the board: the game's point fund on the left, and the round number with a clock on the right.
• Four-stage dice bowl: shows the previous round faintly → clears → question mark → the real result. You can watch the shaking rhythm just like looking at a bowl in person.
• Whole-room points fade in on each square, so you can see which animal the room is leaning toward.
• History & leaderboard: the last 24 rounds, the last 40 matching rounds, and the top 100 players with the most points in the room.
• Chat: you pick your own display name (like "Silly Deer", "Chubby Duck") and a ♂/♀ icon. No account, no email needed.
• Fairy Turtle: a little mascot strolling along the sea floor. Use ← → to guide it and Space to make it jump.
• Self-composed audio: folk holiday background music and a Vietnamese voice are synthesised right on your machine, with separate switches for music and voice in the top-right corner.

There are simulated players in the room

So you never have to wait at an empty table, the room always has some simulated players driven by the program: they pick squares and chat like real people. The "online now" number in the header therefore includes simulated players — we say so here so you know what you are looking at.

How it is built

Everything runs on Rust: the server uses axum + WebSocket to hold the dice results and score for everyone at once, the interface uses Leptos compiled to WebAssembly, and the data packets travel over FlatBuffers. Round history is stored in PostgreSQL, so you can look back after reloading the page.

How to play for fun

• This game is a game of chance — there is no way to play a sure thing, and you do not need one.
• Picking more squares makes your points move more gently; picking one square is more dramatic.
• Keep chat polite: no insults, no spam, no advertising.

Background music

All the classical pieces in the game are in the public domain, taken from the Mutopia Project. The piano sound uses Alexander Holm's Salamander Grand Piano samples, licensed CC BY 3.0.

Contact

Feedback, bug reports, or requests to delete round data: admin@satime.net. See also the Privacy policy, Terms of use and How to play.