一鼓作氣

春秋時代﹝西元前七七零至四七六年﹞齊國派兵攻打魯國。魯莊公和曹劌帶著軍隊抵抗。兩國的軍隊擺開陣勢以後，魯莊公打算擂鼓，命令軍隊向前衝。曹劌卻說：「等一會兒！」等到敵人先擂過三遍鼓以後，纔命令魯國軍隊擂第一遍鼓。鼓聲一停，立即命令軍隊衝過去攻擊。果然，打得齊國軍隊四散奔逃。

後來魯莊公問曹劌，為甚麼敵軍擂過三遍鼓以後，曹劌纔命令魯軍擂鼓。曹劌回答：「打仗最重要的是要有勇氣。擂第一遍鼓，士兵勇氣旺盛，人人想向前衝。擂第二遍鼓，勇氣就會衰退一點兒。等到擂第三遍鼓，勇氣已經消失了，所以我命令軍隊等敵人擂過第三遍鼓以後，再擂鼓。這樣，敵人的勇氣由旺盛而衰退，由衰退而消失。我們卻正是勇氣旺盛的時候，打起仗來，當然成功了。」

One Strike Fires Up The Spirit

During the Spring and Autumn Period, the state of Ch'i attacked the state of Lu. Lord Juang and Tsau Guei led the army to resist the Ch'i troops.

The soldiers of both states were lined up in battle array, and Lord Juang was preparing to strike his drum, ordering his army to advance, when Tsau Guei said, "Wait a minute!" He waited until the enemy had struck their drum three times, before ordering his army to advance. And surprisingly, they fought so well that the Ch'i army scattered in all directions.

Afterwards, Lord Juang asked Tsau Guei why he had waited until the enemy had struck their drum three times before ordering the Lu army to strike their once. Tsau Guei answered, "The most important thing, when fighting a war, is morale. The first time the drum is struck, the soldiers all have high morale. The second time, their morale declines some, and by the third time, their morale is already gone. Therefore, by waiting until the Ch'i army hand struck their drum three times before striking ours once, our soldiers were in high spirits when their soldiers morale was gone. Naturally we won the war."

Today, this idiom can be used to describe a situation in which a person accomplishes a task or project all in one go, as opposed to working at it gradually.