Go
Take turns placing a stone on an empty point. A stone or group with no empty point next to it is captured. When neither player wants to move, both pass — and whoever surrounds more of the board wins. New to it? Start on the small board against the Gentle computer, and try the Go Through the Ages course. Or watch how the masters did it: Famous Go games.
Your online game is still open.
Host a game
Start a room and share the code. You play Black on a 9 × 9 board.
Join a game
Enter the code you were given.
Share this code:
Waiting for your friend to join…
Keyboard: arrow keys move, Enter places a stone.
Counting
Talk it over: are any groups still on the board that could not escape capture? Tap them to mark them out of play (tap again to bring them back). The count updates as you go — agree it together.
Set the table — board size, head start, the computer and the board view
A change here starts a new game.
The computer opponent runs entirely on your device. The classic levels play a beatable game; they are practice partners, not strong engines. The "plays like a person" opponents use KataGo's human-imitation network, trained on games between ranked people: it plays the moves a player of that rank tends to play, mistakes included, without reading ahead, so the rank describes a style rather than a certified strength. Even the 25-kyu one beats the classic Strong level most of the time. Its model (about 28 MB) downloads the first time you choose one, is kept in your browser, and then runs on your device; your moves are never sent anywhere. The count is by area: your stones on the board plus the empty points only you surround. White gets 7½ points for moving second (½ with a head start), so there is never a tie. Online rooms are private: only someone with the code can join. There's no chat and no account, and the room is gone shortly after you leave. If a child is in the room, it follows Spark & Anvil's children's rules.