Looking up...
彼は失策を犯してしまった
He made a bad move
A mistake or blunder, especially in a game or strategic situation
その将棋の一手は明らかな失策だった
That move in shogi was clearly a blunder
彼はビジネスで大きな失策を犯した
He made a major blunder in business
Often used in contexts where a decision or action leads to negative consequences
Often used in games, sports, and business contexts to describe significant mistakes
From 失 (shitsu, 'loss') + 策 (saku, 'strategy' or 'plan')
More commonly used in formal or strategic contexts than casual conversation