noun
constantly changing and unpredictable
A yojijukugo describing a situation or person's tactics that alternate between falsehood and truth, making them hard to read. Often used in strategic or literary contexts.
彼の戦略は一虚一実で、相手はまったく読めなかった。
His strategy was a mix of feints and real moves, and his opponent couldn't read him at all.
一虚一実の駆け引きが、このゲームの醍醐味だ。
The back-and-forth of deception and truth is what makes this game so enjoyable.
A yojijukugo derived from classical Chinese strategic thought, combining 一 (one), 虚 (falsehood/emptiness), 一 (one), and 実 (truth/substance). The exact historical derivation is uncertain, but it reflects the concept of alternating deception and sincerity to confuse an opponent.