False seki

False seki (also called Pseudo-seki) is a position in which opposing groups appear unable to capture one another, but accurate reading shows that one group is actually dead or can be captured.

The apparent mutual restriction is deceptive. A false eye, a shortage of liberties, or a sequence of moves inside the shape may allow one player to capture the group that seemed to be in seki. Recognizing false seki is essential for determining life, death, and territory correctly. Unlike genuine seki, it does not leave both groups unconditionally alive: one group can be killed if the position is played out correctly. Do not judge from the visible shape alone. Read whether either player can force a capture, and account for ko or other relevant contingencies.