The theme of a novel varied, depending on the author's intention and style. Here are some common novel topics: Love: Love is one of the most basic human emotions. Many novels involve the theme of love. 2. Adventure: Many novels involve the theme of adventure, describing the protagonist's journey of exploring the unknown, facing challenges and overcoming obstacles. Fate: Many novels discuss the fate and destiny of humans. After many twists and turns, the protagonist finally achieved his goal. Friendship: Friendship is one of the most beautiful emotions of human beings. Many novels involve the theme of friendship and describe the story of the protagonist and his friends getting through difficulties together. Family: Family is one of the basic units of human society. Many novels involve the theme of family, describing the emotional entanglements and conflicts between the protagonist and family members. Religion: Religion is one of the most important parts of human culture. Many novels deal with the theme of religion and describe the struggle and dialogue between the protagonist and religious leaders or doctrines. Science fiction: science fiction deals with the future world and technology. Many novels involve science fiction, which tells the story of the protagonist exploring the unknown, facing challenges and overcoming obstacles. History: Historical novels explore the theme of human history and cultural heritage. Many novels involve historical topics and describe the emotional entanglements and conflicts between the protagonist and historical figures. These are just a few examples of the theme of a novel. In fact, the theme of a novel is very diverse. Every author has his own unique writing style and theme choice.