When a stone or a small group tries to run away, there are two classic ways to catch it: the ladder and the net. They are among the first capturing techniques any Go player learns, and they stay important at every level. Strong players read ladders across the whole board before they even start a fight, because the answer changes which moves are possible.
This article explains both techniques in words, since the key to both is the reading, not a single picture.
Atari, the starting point
A stone is in atari when it has only one liberty left. If the owner does nothing, the opponent captures it by filling that last liberty. The natural response is to run: extend the stone into its last liberty, hoping the new, longer group has more liberties.
Both the ladder and the net are answers to that running move.
The ladder
A ladder, called shicho in Japanese, is a sequence of ataris that chases a group diagonally across the board. Each time the running group extends, it gains only two liberties, and the attacker immediately takes one of them, putting it back in atari. The group zigzags toward the edge or toward the far side of the board like steps on a staircase.
The ladder works because the running group never gets a third liberty. When it finally reaches the edge of the board, it runs out of room and is captured along with every stone it added on the way. That makes a failed ladder escape very expensive: the owner loses not one stone but a whole line of them.
How to read a ladder
To read a ladder, follow the diagonal path the running stones will take. Picture each step: the runner extends, the attacker ataris from the side that keeps it running in the same diagonal direction. Continue until one of two things happens:
- The path reaches the edge with no help for the runner: the ladder works, the runner dies.
- The path meets a stone of the runner's colour: the runner connects to it and gains liberties, so the ladder fails.
Ladder breakers
A stone lying on the ladder's path that helps the runner is called a ladder breaker. Once a ladder breaker exists, the ladder fails, and the attacking stones that tried to chase are full of cutting points. Your opponent will cut them apart, and your position collapses.
This is why experienced players look far across the board before starting a ladder. A single stone twelve lines away can decide whether a local fight works. It is also why placing a stone that both does something useful and breaks a ladder is a classic strong move: it is a double-purpose play.
Ladders in practice
Some practical advice:
- Never run out of a working ladder. If you have read that the ladder works, do not add stones to the running group. Each stone you add is one more stone lost.
- Never chase a broken ladder. If there is a ladder breaker, choose another way to attack.
- Check both directions. Sometimes the ladder can go two ways; the attacker chooses the direction that works.
- Watch for ladder-breaking threats. An opponent can play a move that threatens to break the ladder while doing something else. If you answer by capturing the laddered stones, you lose tempo; if you ignore it, the ladder is broken.
The net
A net, called geta in Japanese, catches a running stone not by chasing it but by surrounding it loosely. Instead of putting the stone in atari, the attacker plays a move one step away that blocks every escape route. When the runner tries to push out in any direction, it runs into the attacker's stones and gets captured.
A net is often better than a ladder:
- It does not depend on ladder breakers elsewhere on the board.
- It is short, so there is less to read.
- The attacker's stones end up solid, without the cutting points a ladder leaves.
Its disadvantage is that it requires the attacker's surrounding stones to be in the right place already. You cannot net a stone that has open space on two sides.
How to read a net
When you are considering a net, check every way the runner can push. For each push, ask whether your stones block it and put the runner in atari. If every push fails, the net works. If one push reaches open space or a friendly stone, the net fails, and the runner escapes into your territory.
Nets are especially common when capturing a cutting stone: the cutter has few liberties, and a loose surrounding move catches it cleanly.
Choosing between them
When you want to capture a running stone:
- Try the net first. If it works, it is usually the cleanest capture.
- If the net fails, read the ladder. Follow the diagonal all the way.
- If both fail, do not chase. Attack for profit instead, or leave the stone and play elsewhere.
Why beginners should practise these early
Ladders and nets teach two habits that matter at every level: reading a sequence all the way to the end, and looking at the whole board rather than only the local fight. A player who reads ladders properly naturally starts noticing distant stones, which improves every other part of their game.
They are also common in real games, especially on smaller boards. In short 9×9 games against the computer on the home page, you will meet both within a few games. Play people on the online page and you will see opponents run out of ladders they should have abandoned. If you sign in on the account page, you can replay the moment a ladder started and follow the path yourself.
For related skills, see capturing races and cutting and connecting.
Frequently asked questions
What is the difference between a ladder and a net?
A ladder chases a stone with repeated ataris diagonally across the board. A net surrounds it loosely so every escape route is blocked, without repeated ataris.
What is a ladder breaker?
A stone of the runner's colour on the ladder's diagonal path. When the runner reaches it, it connects and escapes, so the ladder fails.
Should I run if my stone is in a ladder?
Only if there is a ladder breaker. If the ladder works, running adds stones that will all be captured.
Why do strong players look at the whole board during a local fight?
Because a distant stone can break a ladder and change the result of the local fight completely.
Is a net always better than a ladder?
Not always, but when a net works it is usually cleaner: no dependence on distant stones and no cutting points left behind.
