Magical realism is a literary style in which fantastical elements are incorporated into realistic literature. It falls under the umbrella of speculative fiction, as it contains components that differ from reality. However, unlike most speculative fiction such as fantasy, science fiction, or dystopian fiction, the majority of the work is still rooted in realism. To define it, it is often explained by how it differs from other forms of speculative fiction.

One key difference between magical realism and more popular forms of speculative fiction is that it must take place in the real world, with largely realistic elements. For example, fantasy is defined by its alternate worlds and fictional creatures, while science fiction relies heavily on futuristic technology or scientific advancements as a focal point for its story and themes. In Keeper, the world that Gato and Faustino live in is realistic except for one component: The Keeper himself. As a magical being, he is able to control the forest he lives in, manipulate the creatures and weather, and spend decades as a ghost, waiting for Gato to win the World Cup and return.

Another key component of magical realism is its roots in folklore.