Oki

Oki, also called Placement, is a move that puts a stone in a gap or other vital point inside, or immediately beside, the opponent’s stones or territorial framework. The point is usually strategically or tactically sensitive: the move exploits weaknesses in the opponent’s shape or available eye space.

An oki may reduce potential territory, prevent the opponent from making secure eyes, induce a response, or create tactical opportunities. It is a specific placement move, so the term is narrower than a general invasion; an oki is not necessarily intended to establish a large group inside the opponent’s framework. The word describes the nature of the move, not its result. Whether the stone succeeds—or eventually lives—is a separate question.