Heart of Darkness draws on several literary genres, including romance, tragedy, symbolic narrative, and colonial adventure. Romance and tragedy are the most traditional genre categories in this list, and Conrad’s novella combines elements from both. Romance narratives typically begin with characters being separated from each other, and the action of the story takes the form of a quest or an adventure that results in a rescue or other form of reunion. Likewise, Marlow’s journey begins with a quest to find and rescue Kurtz. Furthermore, like other romance narratives, Heart of Darkness concludes with a kind of transcendence, in which Marlow rises above the challenges he encounters on his journey. The end of the novella is not, however, a happy one, and in this sense it resembles tragedy. In tragedy, the resolution of the problem that initiated the story’s action often involves the death, banishment, or diminishment of the protagonist. Marlow may have survived his Congolese journey, but as the tone of his story indicates, the experience shook him to his very core. 

Conrad’s novella also functions as symbolic narrative, which is also known as an allegory. In an allegory, surface details imply a secondary meaning. Decoding these secondary meanings provides the reader with a deeper understanding of the story. Often, allegories involve characters who represent moral qualities, and these characters’ actions have moral or spiritual meaning. In the case of Heart of Darkness, Marlow’s ignorance towards the horrors of Belgian colonialism and the bewilderment he experiences throughout his journey into the Congo could be said to represent a state of innocence. By contrast, Kurtz could be said to represent corruption, or perhaps even evil, understood here as being completely deficient of moral judgment. As Marlow travels further along the river and eventually meets Kurtz, he undergoes a spiritual trial in which he is forced to reevaluate his own moral grounding. When Marlow returns to Europe at the end of the novella, he has survived his symbolic encounter with corruption and evil, but he comes away with a fuller understanding of the power that evil can wield. 

 Heart of Darkness also draws on the genre of colonial adventure stories. Such stories sought to thrill readers who remained at home in Europe, unable to venture to far-off colonies. For this reason, writers of colonial adventures often used exotic settings at the margins of empire. These settings were made to appear wild and strange in order to provide a backdrop for dramatic quests that tested the fortitude of European heroes, who triumphed over physical struggles and had daring encounters with the unfamiliar. For instance, the story takes place in the yellow Belgian territory that remains unknown and unexplored, rather than the vast amount of red on the color-coded map Marlow finds in the Company’s office in Brussels, indicating that “one knows that some good works is done there.” While Conrad’s novella incorporates these elements, it distinguishes itself from other colonial adventure stories through its pacing and tone. Whereas most colonial adventures feature fast-paced and thrilling plots, Conrad’s novella has a slower plot that is more ponderous than exciting.