A young prince, confined to a secluded paradise, abandons his sheltered existence to seek the true nature of happiness in the wider world. Rasselas, the son of the King of Abyssinia, finds his life within the Happy Valley monotonous and devoid of purpose. Accompanied by his sister Nekayah, her attendant Pekuah, and the philosopher Imlac, he ventures into Egypt to observe various modes of life and social strata. The narrative functions as a philosophical inquiry, utilizing a linear structure to contrast the prince's idealistic expectations with the stark realities of human existence.

Readers and critics frequently highlight the work as a quintessential example of Enlightenment-era philosophical inquiry. Discussion often centers on the stark contrast between the idyllic setting of the Happy Valley and the disillusioning realities encountered by the protagonists in Egypt. Many observers note that the prose remains dense and highly structured, reflecting the author's commitment to moral and intellectual rigor. The text is often praised for its refusal to offer easy answers, instead encouraging readers to contemplate the inherent complexities of the human condition. Scholars frequently emphasize how the narrative serves as a critique of optimistic philosophies prevalent during the eighteenth century.