Why a garden board?

Go is a big game. A full board has 361 points, and most Go sites are made for people who already play. This page starts small: six taps to learn the rules on a 5×5 board, then the first-capture game, then real Go on 9×9. The wooden board sits on a garden lawn, the stones look like river pebbles, and your opponents are garden animals.

A bit of real Go history

Go comes from China, where it is called weiqi. In Korea it is baduk, and in Japan igo or go. English took the Japanese name. Nobody knows when the game began. An old legend says Emperor Yao made it to teach his son Danzhu, but that is a legend, not history.

The oldest clear written mention is in the Zuo zhuan, a Chinese history put together around the 4th century BC. It records a warning, from about 548 BC, that a nobleman was treating his ruler with less care than a player gives a game of go. The game also turns up in the Analects of Confucius and in the book of Mencius. The oldest board found so far is a stone board with 17 by 17 lines, from a Han dynasty tomb at Wangdu in Hebei. A pottery board with today’s 19 by 19 lines, from around 600 AD, was dug up at Anyang.

By the 7th century the game was played in Korea and Japan. In Japan in the early 1600s, the Tokugawa government gave official support to four go houses, and playing go became a profession. The Nihon Ki-in, the Japan Go Association, was founded in 1924. In March 2016, DeepMind’s program AlphaGo beat the top professional Lee Sedol by 4 games to 1 in South Korea.

The first-capture game is a teaching method from the Japanese professional Yasuda Yasutoshi.

How to play Go

• Black and White take turns putting one stone on an empty point where the lines cross. Black goes first. Stones do not move.
• The empty points next to a stone, along the lines, are its liberties. Stones joined along the lines are one group and share their liberties. A group with one liberty left is in atari.
• Fill a group’s last liberty and you capture it. You may not play where your own stone would have no liberties, unless that move captures.
• Ko: you may not make a move that brings back an earlier board position. This page checks every earlier position, a rule called positional superko.
• In Capture Go, the first capture wins. In full Go, the game ends when both players pass in a row. Dead groups come off. Each side counts its stones on the board plus the empty points it walls in. This is area scoring, as in Chinese rules. White adds 6.5 points, called komi, for moving second, and the half point means there are no draws.

The garden animals

The computer plays out many quick random games from the position and picks the move that wins most often. This is called Monte Carlo tree search. The weaker animals play fewer of these games and sometimes pick a move at random.

• Snail: looks only a little way ahead and often misses captures. Start here, with handicap stones if you like.
• Frog: usually spots captures and saves its stones, but still hops about.
• Tortoise: slow and steady, and rarely gives stones away.
• Swan: thinks for about a second each move. In our test games it beat the Tortoise in 18 games out of 20. It is a fair test for a beginner, but a club player will beat it.

Tips for beginners

Count before you play. When you play next to the other side’s stones, count your own liberties after the move. If only one is left, you are in atari.

Two eyes live. A group with two separate empty points inside it can never be captured. The Make two eyes and Kill puzzles practise this.

Pass when the borders are closed. After both players pass, tap any group to mark it dead or alive, or tap Resume play to settle it on the board.

Your turn

The six Learn steps take a couple of minutes. Then see if you can capture one of Ladybug’s stones before it captures one of yours.