不能自杀，但有例外 | No self-capture, with one exception
在围棋中，有一条基本规则：你不能下一步让自己的棋子没有气。这种走法叫做"自杀"，而那个不能下的位置就叫做禁入点。这条规则看起来简单，但在实战中它有着重要的战术意义。
想象一下：如果你把棋子下在一个被对方棋子完全包围的位置，下去之后你的棋子没有任何气，那这步棋就是自杀——游戏不允许你这样做。禁入点在棋盘上会用特殊标记提示你（在围棋豆豆中显示为红色标记）。
判断一个点是不是禁入点，关键在于：如果你在这个点下棋之后，你的棋子（包括与它相连的所有同色棋子）一口气都没有，那这个点就是禁入点。
下图中，中间的空点被四颗白棋完全包围。如果黑棋下在这里，落下的黑子不会有任何气，所以这是黑棋的禁入点。
红色标记的点就是禁入点。黑棋不能下在那里。
角落只需要两颗棋子就可以创造禁入点：
左上角被两颗白棋封住，黑棋下在角上就没有气了，所以这是禁入点。
边上需要三颗棋子包围才能形成禁入点：
禁入点规则有一个非常重要的例外：如果你下在一个看似没有气的位置，但这步棋能吃掉对方的棋子，那么这步棋是合法的！
这是因为围棋的处理顺序是：先检查是否能吃掉对方，然后再检查自己是否有气。如果吃掉对方后，你的棋子有了气，那这步棋就不算自杀。
下图中，中间的空点（绿色标记）被四颗白棋包围，看起来黑棋不能下。但仔细看——左边和右边的白棋各自只剩这1口气！黑棋下在这里就能吃掉它们！
绿色点就是左右两颗白棋的最后一口气。黑棋下在这里虽然看起来被四面白棋包围（自杀），但因为能吃掉左右两颗白棋，吃掉后黑棋就有了气，所以这步棋是合法的！
禁入点不仅仅是关于单颗棋子的。如果你下一颗棋子后与旁边的同色棋子连接，那么要看整个连接组是否有气。
举个例子：一个位置看起来没有气，但如果你下在那里后与旁边的同色棋子连接成一个整体，而这个整体有气，那这步棋就是合法的——不算自杀。
上图中绿点的位置，虽然看起来三面被白棋包围，但黑棋下在那里后会与右边的黑棋连接，形成的整体还有气，所以这步棋是合法的。
理解禁入点规则对你的棋力提升很有帮助：
禁入点规则可以用两句话概括：
掌握这个规则后，你就理解了围棋最基本的规则之一。下一课我们将学习另一个重要规则——打劫。
In Go, there is a fundamental rule: you cannot play a move that leaves your own stone with no liberties. Such a move is called "suicide," and the position where you cannot play is called a forbidden point. While this rule seems simple, it has significant tactical implications in actual games.
Imagine placing a stone on a point completely surrounded by your opponent's stones. After placing it, your stone would have zero liberties -- that is suicide, and the game does not allow it. Forbidden points are marked with special indicators on the board (shown as red marks in Cute Go).
To determine if a point is forbidden, the key question is: after you place a stone there, does your stone (including all same-colored stones connected to it) have zero liberties? If so, it is a forbidden point.
In the diagram below, the center empty point is completely surrounded by four white stones. If Black plays here, the black stone would have no liberties at all, making this a forbidden point for Black.
The red-marked point is the forbidden point. Black cannot play there.
In the corner, only two stones are needed to create a forbidden point:
The top-left corner is blocked by two white stones. If Black plays in the corner, it would have no liberties, so this is a forbidden point.
On the edge, three stones are needed to surround and create a forbidden point:
The suicide rule has one crucial exception: if playing on a seemingly liberty-less point captures your opponent's stones, the move is legal!
This is because Go processes moves in a specific order: first check if the move captures any opponent stones, then check if your stones have liberties. If capturing the opponent gives your stones liberties, the move is not suicide.
In the diagram below, the center point (green marker) is surrounded by four white stones — it looks like Black cannot play there. But look closely: the white stones on the left and right each have only 1 liberty left (this very point)! Black can play here and capture them!
The green dot is the last liberty for the white stones on the left and right. Playing here looks like suicide (surrounded by four white stones), but since it captures the left and right white stones, Black gains liberties after the capture — making this move completely legal!
The forbidden point rule is not just about single stones. If you place a stone that connects to adjacent same-colored stones, you must check whether the entire connected group has liberties.
For example: a point may appear to have no liberties, but if your stone there connects with adjacent friendly stones to form a group that has liberties elsewhere, the move is legal -- it is not suicide.
In the diagram above, the green dot position appears surrounded on three sides by White. But if Black plays there, it connects with the black stone to the right, and the resulting group still has liberties, making this a legal move.
Understanding the suicide rule can significantly improve your play:
The suicide rule can be summarized in two sentences:
With this rule mastered, you understand one of Go's most fundamental rules. In the next lesson, we will learn about another important rule -- the ko rule.