What adjective describes a narrative involving clever rogues or adventurers?

The adjective that describes a narrative involving clever rogues or adventurers is "picaresque." This term comes from the genre of picaresque novels, which typically feature a roguish protagonist who navigates through various adventures and misadventures in a satirical or humorous manner. These narratives often focus on the protagonist's experiences in a corrupt society, emphasizing their cunning and resourcefulness as they confront various challenges.

In contrast to the other options, "pernicious" refers to something that is harmful or destructive, particularly in a gradual way; "philosophical" pertains to the study of fundamental questions about existence and knowledge; and "perpetual" describes something that is everlasting or continuous. None of these terms encapsulate the adventurous and cunning spirit found in picaresque narratives. Thus, the most fitting descriptor for a story centered around clever rogues or adventurers is indeed "picaresque."