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One way to approach world building is to think about elements of our world that you can twist around or use as a jumping off point. You may try reimagining your daily commute to work by flipping one element on its head, like a bus that is upside down or a commuter who is a goblin from another time period. Reality, or the real world, are good building blocks for creating a believable fantasy world. You may also use elements of the world that you find disturbing or troubling and use them as the building blocks for your dark fantasy world. For example, maybe you dislike your office job and translate this dislike into a disturbing world where ghosts work office jobs. Or, maybe you want to examine abortion and use it as a jumping off point for a dark fantasy about a world where women are infertile and second class citizens in a totalitarian regime. You may also use a certain historical time period or major historical event as inspiration for the world of your story. Leaning on history can help you to build off of reality and create a world where readers can see parallels with their own history. Maybe you are interested in the Civil War and end up creating a world where the Civil War failed, leading to consequences for characters in your world. Or, maybe you use the bombing of Hiroshima as a model for a catastrophic event that occurs in the world of your story, creating characters who have special abilities due to their exposure to radiation. Many dark fantasy novels are “retellings” of myths, legends, and popular stories. These retellings are often done by twisting or turning certain elements of the existing story to make it new or strange. This approach can be useful for building a world that feels eerily familiar to a reader but also slightly off. Adding disturbing elements to an existing story can also present a different take on a familiar tale. For example, maybe you love Disney’s The Little Mermaid. You may then put your own take on the story, choosing a minor character in the tale and making them the main character, or reshaping the story so it is set in an underwater setting full of danger and horror that was not as present in the Disney version. Another option is to focus small and limit your world to a small area. This could be an enchanted house, a shape shifting street, or a town filled with misfits and supernatural beings. Sometimes, limiting the scope of your world can actually make it easier for you to focus on the small details and nuances of the setting. You can also have characters who interact with each other often in a small space, leading to a higher potential for drama and conflict in the story. You may also have the setting act as another character in the story. For example, maybe your story is set in a mansion that has supernatural abilities and a mind of its own, creating danger and horror for the inhabitants of the mansion. Or, maybe the small town has a dark secret that they are trying to keep hidden, especially when a newcomer rolls into town asking questions. Once you have determined the world of the story or the setting, you should sit down and consider the details of the world. Think about the rules and customs of the world, as well as the traditions and habits of people who live in this world. Consider if there is a governing body in the world and how they exert their authority over their people. These details will help you create a more believable, well rounded fantasy setting.  For example, your world may be run by aristocratic families who compete for territory, with customs that require lesser born people to follow these families. You may also have supernatural beings who exist in this world as second class citizens and outcasts, considered lesser than the aristocratic families who rule the people. This hierarchical structure of the world should come into play once your get characters into the setting. You may also have a dark fantasy world that resembles our world, except for a few strange habits and customs. For example, maybe instead of working in an office, people work in pods connected to a life force in the basement. Or, maybe instead of hopping on a bus, people hop on supernatural animals who act as taxis for humans. Another key detail of world building is to consider how people speak and communicate. Many dark fantasy worlds have characters who have their own language(s) and ways of communicating that may be different than our own. Considering this detail will allow you to create a richer and more complex fantasy world. For example, you may decide to have some characters speak English, or your mother tongue, and some characters speak a fantastical language. You may then use an existing language, with a few changes, or create your own language that is only spoken by certain characters or beings.

Summary:
Use elements of our world to create your own. Model your world on a historical time period or event. Turn an existing story or myth on its head. Confine your world to a small area, like a house, a street, or a small town. Consider the customs and traditions of the world. Create a language specific to the world.