ko threat
A move in the game of Go that creates a threat elsewhere on the board, forcing the opponent to respond and allowing the player to retake the ko.
Without a ko threat, you cannot win the ko.
He played a ko threat and then immediately took the ko back.
Common spelling in Go contexts, using katakana コウ for the ko rule.
Kanji spelling using 劫 (ko); less common but seen in some Go literature.
Compound of コウ (ko, from the Go term for the ko rule) and 材 (ざい, material). The term literally means 'ko material', referring to a move used as a resource in a ko fight.