The Stratagems of the Warring States belongs to the genre known in Chinese as "persuasions" (説). These were short historical anecdotes intended to be used by politicians and diplomats to bolster their arguments.
While the episodes described in the book all take place between the fifth and third centuries BC (the Warring States era), they were not collected into a single volume until the Han Dynasty, when Liu Xiang set about bringing some order to the imperial archives, grouping diverse existing material into standard compilations.
The world they describe tends to be regarded as a dark period of Chinese history, defined by perpetual conflict between dozens of feudal states. However, it was also a time of unparalleled freedom and intellectual exuberance, when a hundred schools of thought genuinely did contend. Competition between states turned civil service employment into a sellers' market and constant upheaval allowed great potential for social mobility. In such an environment, a smart and opportunistic peasant could not merely speak his mind to a prince, but rise to become one.
The Stratagems reflect this atmosphere. While the stories are populated with grifters, parasites and warlords, the evident delight taken by the characters in their own intellectual chutzpah gives them an unfailing charm, even at their worst moments.
Finally, it is worth noting that while the Stratagems is a history book, it should not necessarily be read as a catalogue of facts. Stories are occasionally attributed to individuals who could not possibly have participated in them, and characters interact whose lifespans did not intersect. The classical Chinese approach to historiography preferred to give multiple perspectives on any given event, building up a 360-degree collage of commentaries without coming down in favour of one or the other. The Stratagems is a reflection of this preference and, arguably, all the better for it.
While Liu Xiang made an effort to catalogue each state's stories in chronological order, this pattern is not always followed, and they were not originally intended to be read in any particular sequence.