noun
The Six Secret Teachings and The Three Strategies of Huang Shigong
Refers specifically to two ancient Chinese military classics: 六韜 (Rikutō) and 三略 (Sanryaku). Used in historical or literary contexts.
彼は六韜三略を熟読し、兵法の奥義を極めた。
He thoroughly read The Six Secret Teachings and The Three Strategies and mastered the secrets of military strategy.
noun
secrets of the art of war; mysteries of strategy
Figurative extension: refers to profound knowledge or secrets of military tactics, or more broadly any arcane expertise. Often used in the phrase 六韜三略を極める.
彼は商売の六韜三略を心得ている。
He knows all the secrets of the trade.
From the titles of two ancient Chinese military treatises: 六韜 (Rikutō, 'Six Secret Teachings') and 三略 (Sanryaku, 'Three Strategies'). The compound is used as a yojijukugo to refer to these works or, by extension, to profound strategic knowledge.