shicho

An ancient Go proverb states "Do not play Go if you do not know the ladder". What the ladder is is essentially a deathtrap for a group of stones. It is easy to recognize after you have played for a while but beginners often fall prey to it. One common example is shown below, the "X"s are black stones and the "O"s are the white ones, a period denotes a blank space, it is white's turn.

.............
....xx.......
...xo*.......
....x........
.............

An newbie would try to save their stone by playing at the "*". Lets see what happens next.

.............
....xx.......
...xoox......
....x*.......
.............

Black then responds by cutting off one of white's exits and putting the group in atari. Looks like white is in the same spot, it tries to play at the next asterisk to try and save its group now composed of two pieces.

.............
....xx.......
...xoox......
....xo*......
.....x.......

.............
....xx.......
...xoox......
....xoox.....
.....x*......

.............
....xx.......
...x..x......
....x..x......
.....x.x.....

I think you can see where this goes, white ends up with a rather substantial group captured and black is free to do a victory dance. Any situation like this will eventually hit a wall resulting in a capture for the opposing side. It is possible to setup a safety net that your group will run into that saves it, if you can do this you can quickly shred the poor defense that black has erected in trying to capture the ladder group.

The ladder is a potent weapon against newbies but once you begin to play intermediate and advanced games don't rely on it as an offensive weapon, most players will just accept the one piece loss and play somewhere more productive.

Shicho is the Japanese term for a method of capture in the board game go. The English term is ladder.

Shicho is one of the two fundamental methods of capture in go, the other being geta (net in English).

..........
..........
..........
..O.......
.OX.......
..OO......
..........

Note the black stone (X) has only one liberty. Though it hadn't been captured yet, it is good as dead, because it is caught in the shicho, or ladder. If black tries to escape...

..........          ..........
..........          ..........
..........          ..........
..O.......          ..O.......
.OXX......          .OXXO.....  <--- white responds by again putting
..OO......          ..OO......       black in atari.
..........          ..........

As you can see, it is hopeless for black to persist in this attempt to escape, because eventually, this shicho leads to the edge of the board.

.....OX...   <--- even if black plays the next step in the shicho,
....OXXO..        he still only has one liberty, and is captured.
...OXXO...
..OXXO....
.OXXO.....
..OO......
..........

However, black could persist if there was a ladder breaker present...

..........                      .....O....
.......X..  <--- ladder         ....OXXX..   <--- black escapes
..........       breaker        ...OXXO...
..O.......                      ..OXXO....
.OXX......                      .OXXO.....
..OO......                      ..OO......
..........                      ..........

Serious players read this out ahead of time, and won't persist in trying to escape if there is no chance of escaping, and likewise, one would not persist in trying to capture by shicho if there is a ladder breaker present.

The ability to read ladders before making moves is one of the fundamentals of go strategy.