One of the foremost motifs at the heart of fantasy literature is the interplay between good and evil and the problems thrown up by this duality. Frequently, these two elements are endowed with religious overtones, and divide the novel's world into very clearly delineated regions of good and evil. Taking "The Lion, the Witch and the Wardrobe" by C.S. Lewis as an example, we can see this conflict between powers of good and of evil portrayed explicitly in the form of an actual war taking place within the novel. This allows Lewis to introduce themes familiar to the Judeo-Christian religions; moral themes of temptation, betrayal and ultimate redemption.
Fantasy literature is not simply about the moral dilemma between good and evil. A good proportion of fantasy literature seeks to provide escapist thrills to the reader. The novel provides a place for a writer to create a world in which he can set his own rules and then allow his characters to explore this world. Fans of fantasy literature want to be taken on a journey that could not exist in real life. As a result, such literature often concerns itself with magic and mythology, conjuring up mythical beasts from Roman, Greek and Nordic legends and making the use of magic a very real possibility within the book.
The theme of the quest or redemptive journey is embedded deeply into the fantasy genre. Tying in with the good and evil duality, much of fantasy literature involves characters on a heroic quest for love, glory or simply for an altruistic cause. These journeys are presented as allegorical metaphors for self-improvement and piety in real life.
In its history, the genre of fantasy has frequently crossed over into its own dark-side: horror fiction. Dark fantasy -- fantasy that includes scarier and more gory and lurid themes -- has developed alongside mainstream fantasy as a sort of evil doppelganger. Amongst the most famous exponents of this genre are Edgar Allen Poe and Anne Rice, who's celebrated Vampire Chronicles is one of the more recent examples of an integration of macabre horror and sword and sorcery fantasy tradition.