Thirty-Six Stratagems
Origin: The name of the collection comes from the Book of Qi's seventh biographical volume, Biography of Wang Jingze (王敬則傳). Wáng was a general who had served Southern Qi since the first Emperor Gao of the dynasty. When Emperor Ming came to power and executed many members of the court and royal family for fear that they would threaten his reign, Wang believed that he would be targeted next and rebelled. As Wang received news that Xiao Baojuan, son and crown prince of Emperor Ming, had escaped in haste after learning of the rebellion, he commented that "of the thirty-six stratagems of Lord Tán, retreat was his best, you father and son should run for sure." "Lord Tán" refers to general Tan Daoji of the Liu Song dynasty, who was forced to retreat after his failed attack on Northern Wei, and Wang mentioned his name in contempt as an example of cowardice.
The number thirty-six was used by Wang as a figure of speech in this context, and is meant to denote "numerous stratagems" instead of any specific number. Wang's choice of this term came from the I Ching, where six is the number of yin that shared many characteristics with the dark schemes involved in military strategy. As thirty-six is the square of six, it therefore acted as a metaphor for "numerous strategies". Since Wang did not refer to any thirty-six specific stratagems, the thirty-six proverbs and their connection to military strategies and tactics are likely to have been created after the fact, with only the collection's name being attributed to Wang.
The prevailing view is that contents of the Thirty-Six Stratagems originated in both written and oral history. Some stratagems reference occurrences in the time of Sun Bin, approximately 150 years after Sun Tzu's death. The original hand-copied paperback was believed to have been discovered in China's Shaanxi province, of an unknown date and author, and put into print by a local publisher in 1941. The Thirty-Six Stratagems came to the public's attention after a review of it was published in the Chinese Communist Party's Guangming Daily newspaper on September 16, 1961. It was subsequently reprinted and distributed with growing popularity.
The Thirty-Six Stratagems are divided into a preface, six chapters containing six stratagems each, and an incomplete afterword that was missing text. The first three chapters generally describe tactics for use in advantageous situations, while the last three chapters contain stratagems that are more suitable for disadvantageous situations. The original text of the Thirty-Six Stratagems has a laconic style that is common to Classical Chinese. Each proverb is accompanied by a short comment, no longer than a sentence or two, that explains how said proverb is applicable to military tactics. These 36 Chinese proverbs are related to 36 battle scenarios in Chinese history and folklore, predominantly of the Warring States period and the Three Kingdoms period.

Content: The Thirty-Six Stratagems consists of six chapters, with each chapter consisting of six stratagems.

Chapter 1: Winning Stratagems (勝戰計, Shèng zhàn jì): 

Deceive the heavens to cross the sea (瞞天過海, Mán tiān guò hǎi): Mask one's real goals from those in authority who lack vision by not alerting them to one's movements or any part of one's plan.

Besiege Wèi to rescue Zhào (圍魏救趙, Wéi Wèi jiù Zhào): When the enemy is too strong to be attacked directly, attack something they cherish. The idea is to avoid a head-on battle with a strong enemy, and instead strike at their weakness elsewhere. This will force the strong enemy to retreat in order to support their weakness. Battling against a tired and dispirited enemy will give a much higher chance of success.

Kill with a borrowed knife (借刀殺人, Jiè dāo shā rén): Attack using the strength of another when in a situation where using one's own strength is not favourable. For example, trick an ally into attacking them or use the enemy's own strength against them. The idea is to cause damage to the enemy via a third party.

Wait at leisure while the enemy labors (以逸待勞, Yǐ yì dài láo): It is advantageous to choose the time and place for battle while the enemy does not. Encourage the enemy to expend their energy in futile quests while one conserves their strength. When the enemy is exhausted and confused, attack with energy and purpose.

Loot a burning house (趁火打劫, Chèn huǒ dǎ jié): When a country is beset by internal problems, such as disease, famine, corruption, and crime, it is poorly-equipped to deal with an outside threat. Keep gathering internal information about an enemy. If the enemy is in its weakest state, attack them without mercy and annihilate them to prevent future troubles.

Make a sound in the east, then strike in the west (聲東擊西, Shēng dōng jī xī): In any battle the element of surprise can provide an overwhelming advantage. Even when face-to-face with an enemy, surprise can still be employed by attacking where they least expect it. Create an expectation in the enemy's mind through the use of a feint. Manipulate the enemy to focus their resources somewhere before attacking elsewhere that is poorly defended. Tactically, this is known as an "open feint".

Chapter 2: Enemy Dealing Stratagems (敵戰計, Dí zhàn jì): 

Create something from nothing (无中生有, Wú zhōng shēng yǒu): A plain lie. Make somebody believe there was something when there is in fact nothing or vice versa.

Openly repair the gallery roads, but sneak through the passage of Chencang (明修棧道，暗渡陳倉, Míng xiū zhàn dào, àn dù Chéncāng): Deceive the enemy with an obvious approach that will take a very long time, while ambushing them with another approach. It is an extension of the "Make a sound in the east, then strike in the west" tactic, but instead of merely spreading misinformation to draw the enemy's attention, physical decoys are used to further misdirect the enemy. The decoys must be easily seen by the enemy to draw their attention while acting as if they are meant to do what they are falsely doing to avoid suspicion.
Today, "sneaking through the passage of Chencang" also has the meaning of having an affair or doing something that is illegal.

Watch the fires burning across the river (隔岸觀火, Gé àn guān huǒ): Delay entering the field of battle until all other parties become exhausted by fighting amongst each other. Go in at full strength and finish them off.

Hide a knife behind a smile (笑裏藏刀, Xiào lǐ cáng dāo): Charm and ingratiate oneself with the enemy. When their trust is gained, move against them in secret.

Sacrifice the plum tree to preserve the peach tree (李代桃僵, Lǐ dài táo jiāng): There are circumstances where short-term objectives must be sacrificed in order to gain the long-term goal. This is the scapegoat strategy where someone suffers the consequences so that the rest do not.

Take the opportunity to pilfer a goat (順手牽羊, Shùn shǒu qiān yáng): While carrying out one's plans, be flexible enough to take advantage of any opportunity that presents itself, however small, and avail oneself of any profit, however slight.

Chapter 3: Offensive Stratagems (攻戰計, Gōng zhàn jì): 

Stomp the grass to scare the snake (打草驚蛇, Dǎ cǎo jīng shé): Do something unaimed, but spectacular ("hitting the grass") to provoke a response from the enemy ("startle the snake") to have them give away their plans or position. Do something unusual, strange, and unexpected to arouse the enemy's suspicion and disrupt their thinking. It is more widely used as a warning: "[Do not] startle the snake by hitting the grass". An imprudent act will give one's position or intentions away to the enemy.

Borrow a corpse to resurrect the soul (借屍還魂, Jiè shī huán hún): Take an institution, a technology, a method, or even an ideology that has been forgotten or discarded and appropriate it for one's own purposes.

Lure the tiger down the mountain (调虎離山, Diào hǔ lí shān): Never directly attack an opponent whose advantage is derived from their position. Instead, lure them away from their position to separate them from their source of strength.

In order to capture, one must let loose (欲擒故縱, Yù qín gù zòng): Cornered prey will often mount a final desperate attack.