The novel portrays the excesses and moral decay of the French aristocracy in the late 18th century, during the ultimate decline of the Ancien Régime, a time when libertine attitudes towards sex and pleasure were becoming more prevalent. With very few exceptions, the main characters are indifferent to the traditional moral codes of society. Adultery, premarital sex, and other forms of sexual transgression are depicted as commonplace, forming a power struggle between men and women. The dissolute lives and amorality of the main characters embody the corruption at the heart of the old aristocratic class and the emotional emptiness of their lives.

This power struggle is most notable in the two protagonists, the Vicomte de Valmont and the Marquise de Merteuil. These two characters view sex and seduction as a means of gaining power and influence over others. Valmont, while enjoying the pleasures of sexual intercourse, is motivated mainly by the egotistical satisfaction seducing women brings him. While he can share lovers, he must always be the preferred lover, as witnessed in Letter 51 and the love triangle between himself, Vressac, and the Comtesse. When women attempt to resist his advances, as Tourvel and Cécile do, he pressures them into sex through either intimidation (Cécile) or emotional blackmail by vowing to die by suicide if denied (Tourvel).