Building Believable Magic Systems in Urban Fantasy

One of the key elements that defines urban fantasy is the integration of magical elements into the modern world. Whether it’s a hidden society of magical beings, a world where spells and supernatural creatures roam the streets, or the exploration of a character’s newfound magical powers, the magic system in an urban fantasy setting must feel both extraordinary and plausible. Readers need to believe that magic can exist within the framework of their everyday lives without shattering the suspension of disbelief. But how do you create a magical system that feels authentic while staying grounded in the real world?

In this post, I’ll take you through an in-depth guide to building unique and believable magic systems in urban fantasy. We’ll discuss the importance of internal consistency, the balance between magic and real-world rules, and how to keep your readers hooked without losing their trust in the world you’ve created.

1. Establishing Rules for Magic

The first step in crafting a believable magic system is setting clear rules for how magic works in your world. While magic allows for immense creativity and wonder, it also requires structure. Without established rules, magic becomes too arbitrary and unpredictable, making it difficult for readers to connect with the world you’ve built.

Why Rules Matter:

  • Internal Consistency: A magic system must adhere to its own logic. If magic behaves differently without explanation, it risks confusing or frustrating readers. The moment magic becomes a convenient plot device that appears without proper foreshadowing, you lose the trust of your audience.
  • Limits and Costs: Every magic system should have limitations. Power without limitations feels contrived. Magic should come with costs, whether it’s physical tolls on the user, restrictions on its use, or even social consequences. For instance, maybe casting a spell drains a person’s energy, risks the safety of a loved one, or only works at a certain time of day. These limitations make magic feel earned and give characters something to struggle with.

Think about Jim Butcher’s The Dresden Files, where Harry Dresden’s magic is often limited by the amount of energy he can draw from the world, the danger it poses to him personally, and the rules of the White Council. Dresden’s magic is consistent but not unlimited, and he is always mindful of the cost of each spell.

2. Make Magic a Part of the World’s Framework

In urban fantasy, magic doesn’t just exist in isolation—it interacts with the real world. For your magic system to feel believable, it should be integrated into society, politics, culture, and even economy, as though it’s always been a part of the world. That is, unless the magic of your world is held in secret among only those in the know… say an underground world of witches like in my Blood Angel Series, for example.

Creating a Magical Ecosystem:

  • Hidden vs. Known Magic: Is magic something that society is aware of, or is it hidden from the public? In many urban fantasy stories, magic is concealed from the general public, adding a layer of mystery and intrigue. However, even in these worlds, magic should still have an impact on the economy, government, or society. Maybe magical beings run secretive industries, or powerful witches control the black market of enchanted items.
  • Magical Institutions and Regulations: Think about how magic would be regulated, if at all. Are there organizations that oversee magical activities? Is magic illegal for certain people or in certain areas? How does the magical community interact with the mundane world—do they cooperate, conflict, or hide from each other? Exploring these societal dynamics can help ground your magic system in reality and avoid making it seem like an arbitrary addition to the plot.

For example, Laurell K. Hamilton’s Anita Blake: Vampire Hunter series presents a world where vampires, werewolves, and other supernatural creatures are not only known but have legal rights and recognition, with the government regulating these creatures’ activities. The existence of supernatural beings is integral to society’s politics, and the magic in the world reflects that integration.

3. Determine the Source of Magic

One of the most important decisions when creating a magic system is determining where the magic comes from. Magic can be drawn from a variety of sources—nature, gods, emotions, the mind, or even technology. The source of magic will significantly shape how it functions and is understood in your world.

Common Sources of Magic:

  • Elemental Forces: Magic that taps into the natural world, such as fire, water, or earth, is a common source of power. This can create a connection between magic and the environment, adding depth to the system. For instance, a fire mage might have to be near a flame or rely on natural heat sources to use their powers, making the system more tangible and grounded.
  • Bloodlines or Heritage: Magic might be passed down through generations or tied to specific bloodlines. This can create tension within societies, with some families hoarding power, others struggling to access their abilities, or even forbidden forms of magic associated with certain ancestries.
  • Energy or Willpower: Magic could be powered by an individual’s physical, mental, or emotional energy. A magic user might have to tap into their own life force, willpower, or emotions like anger, sadness, or love to fuel their spells. This can create complex inner conflict, as characters may hesitate to use magic for fear of personal loss.
  • Technology and Science: Some urban fantasy systems blend technology and magic, where magic is not a mystical force but a scientific one, often with technological advancements enabling magical phenomena. Think of how techno-magic systems like those in the Shadowrun series blend cybernetics with spellcasting or enchanted machines.

By establishing where your magic originates, you not only create more specific rules for your system but also provide readers with a clearer understanding of its limitations and potential.

4. Incorporate Magic into Character Development

The use of magic in urban fantasy often plays a central role in character development. A character’s relationship with magic can reveal a lot about their personality, values, and struggles. This is where character-driven conflict can shine—especially if magic isn’t simply a tool, but something that challenges or alters the character’s life.

Examples of Magic and Character Development:

  • Moral Dilemmas: A character might have access to immense magical power but must choose whether to use it for good, evil, or for personal gain. This inner conflict can shape their journey. In The Dresden Files, Harry Dresden’s magic comes with deep moral consequences. His choices, especially when using darker forms of magic, define who he is as a person and affect his relationships.
  • Physical or Emotional Limitations: Magic could come with a physical toll, such as the deterioration of the user’s health or mind. Alternatively, magic might amplify a character’s emotional state. This can add depth to characters, making their struggles more relatable and the magic itself a more integral part of the narrative. For instance, a character might be too emotionally unstable to control their magic, creating tension and stakes.
  • Identity and Belonging: If magic is tied to heritage or bloodlines, a character may feel the weight of their ancestry, the pressure of expectation, or even a sense of loss if they cannot access their magical heritage. How they grapple with their magical identity can be central to their character arc.

5. Use Magic to Enhance the Story, Not Dominate It

While magic is an essential component of urban fantasy, it should never overpower the story. The best urban fantasy integrates magic in ways that enhance the plot, drive character development, and add intrigue to the world—without allowing magic to solve all the problems instantly.

Balance Between Magic and the Mundane:

  • The magical and mundane worlds should interact, not just coexist. Often, the challenges in urban fantasy arise from the friction between these two realms. Magic might make life more complicated rather than easier. This keeps the stakes high and forces characters to think creatively and make tough choices.
  • Magic should be a tool, not a crutch. It can help drive the plot forward, but it shouldn’t remove all challenges. There needs to be an element of danger, uncertainty, and complexity even in magical situations. For example, perhaps magic is unreliable in certain circumstances, or the protagonist’s power might not be enough to overcome an adversary without sacrifice.

Crafting a believable magic system in urban fantasy is an exciting challenge, but it requires careful thought and structure. The magic must be consistent, integrated into the world, and tied to real-world consequences to maintain the suspension of disbelief. By establishing rules, creating a system that fits the world, and using magic as a tool for character development, you can create a magical system that feels grounded, logical, and, most importantly, immersive. When done well, magic becomes more than just a fantastical element; it becomes an integral part of the world, deepening both the stakes of the story and the richness of the characters within it.


Charlie N. Holmberg’s BOOK OF MAGIC

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Charlie N. Holmberg’s Book of Magic
By Charlie N. Holmberg
Genre: Speculative Nonfiction, Writing Self-Help

Unravel the secrets to crafting a masterful magic system from best-selling fantasy author Charlie N. Holmberg.

Whether using magic as flavor or as an essential piece of plot, this book will guide fantasy authors, from new to experienced, through the delicate layers of creating, utilizing, and mastering magic systems.

In this book, we will…
*Discuss the schools, laws, and spectrum of magic
*Learn to build individual pieces of a magic system
*Dig into magic’s influence on worldbuilding
*Examine different types and styles of magic
*Develop and polish original magic systems

With workshops, work pages, and reference materials included, this succinct one-and-done guide to crafting the magical elements of the fantasy genre is a must-have for speculative fiction authors.

“If you haven’t had the fortune of attending one of Charlie’s writing classes (which I have), this is the next best thing. Book of Magic contains so much wit, wisdom, and practical suggestions for helping any beginning author, or veteran, make their magic systems rise up and be noticed. She uses expert examples from other authors you know as well as teaching a masterclass on developing magic systems from scratch based on methods she’s invented. You just may need this book to help find out what kind of magic-based diseases might be festering in your neighbor’s cabbages.” —Jeff Wheeler, Wall Street Journal bestselling author of the Kingfountain series

Amazon * Bookbub * Goodreads

Charlie N. Holmberg is a Wall Street Journal and Amazon Charts bestselling author of fantasy and romance fiction, including the Paper Magician series, the Spellbreaker series, and the Whimbrel House series, and writes contemporary romance under C. N. Holmberg. She is published in over twenty languages and is a Goodreads Choice Award, ALA, and RITA finalist. Born in Salt Lake City, Charlie was raised a Trekkie alongside three sisters who also have boy names. A BYU alumna, she discovered in her thirties that she’s actually a cat person. She lives with her family in Utah. Visit her at http://www.charlienholmberg.com.

Website * Facebook * X * Instagram * Bookbub * Amazon * Goodreads

What inspired you to write this book?

In the brainstorming process, I almost always discover my stories’ magic first. Whether it’s a full-fledged magic system (like in The Paper Magician) or just a spark of magic (like in Followed by Frost), my brain loves the fantasy element of fantasy novels and beelines straight to that. I think I was in a conference or the like and the idea of writing a craft book on magic came to mind—I jotted it down in the bottom corner of my notes. But of course, I didn’t have TIME to write something like that. It was just an idea, but it’s an idea that liked to revisit my brain once in a while.

When I got an idea for what I could include in the book, I would jot it down. I teach a class at conferences about magic systems, but I didn’t think that would be enough for my own craft book—I wanted to have things in there that were new and fresh, so I tried to brainstorm in that direction. My brain would collect ideas here and there; record them in a notebook or on my phone. And then at the beginning of the year, in between other fiction projects, I thought, “Well, why don’t I just outline it?”

I found I enjoyed it. I outlined it and then just brain-dumped my thoughts under every section. I went into the PowerPoint for my magic class and pulled it in. I know workshops really help to cement an idea, so I wanted to include those in the book as well, even designing them so readers can write directly onto the page as they go. Oliver Heber Books had reached out to me for the possibility of publishing previously, so the route was set!

What can we expect from you in the future?

I don’t have any more craft books on the docket right now, but I’m full steam ahead on fantasy fiction! I’ll be completing my Whimbrel House series (book 4, Wizard of Most Wicked Ways, releases March 4th, 2025, and I’ll draft book 5 next year), and I’m releasing a romantasy duology called The Shattered King, with book one coming out next fall. After those series are finished, I’ll be releasing a historical series—the first book is called The Hedge Witch’s Cure for Marriage, and I’m very excited for it!

Did you learn anything during the writing of your recent book?

So in Charlie N. Holmberg’s Book of Magic, I have several appendices for writers to utilize. One of these appendices is a list of commonly used magic in fantasy novels. This list can be used in three ways: 1) choosing one of these magics to ensure an easier learning curve for magic for the reader, 2) avoiding these magics to encourage a more original magic system, or 3) twisting one of the magics to make it your own.

I was thinking about this while playing Final Fantasy XVI with my husband, and I thought, okay, what if I took my own advice? What if I took something off this list and did #3 (twisted it)?

So I chose healing magic. How would I find a way to make it uniquely mine? And I came up with an idea that really stuck with me. That idea had babies with Final Fantasy XVI (the MMC is inspired by Joshua Rosfield), and then playdates with [ahem, my favorite novel] The Bird and the Sword by Amy Harmon and To Poison a King by S.G. Prince. And I drafted that book in fifteen days. It wasn’t even a twinkle in my eye in May and it existed in July.

So . . . check out that appendix, I guess. It’s MAGICAL (pun intended).

Anything specific you want to tell your readers?

I created this book to help other fantasy authors craft fun, believable magic systems, but I think it would be a fun read for those who just enjoy reading fantasy. Sometimes it’s fun to peek behind the curtain. 😉

If your book had a candle, what scent would it be?

Paper and ink to set the reader at ease, a bright lilac to inspire creativity, sharp lemon to mimic magic, and freshly cut grass for theme (that one will make sense after you read it).

Fun Facts/Behind the Scenes/Did You Know?’-type tidbits about the author, the book or the writing process of the book.

Obviously one cannot write an adequate book on magic systems without talking about Brandon Sanderson.

Once upon a time, I hired a good friend of mine as a personal assistant/head editor. Her name is Kristy, and she’s one of the most competent people I know. I wasn’t utilizing her full skillset, so when a bigger, better job offer for her came along, we parted ways amicably.

Said job offer happened to be for Dragonsteel, which is Brandon’s company.

In Charlie N. Holmberg’s Book of Magic, I wanted to address Brandon Sanderson’s laws of magic, but I wanted to make sure I did it in a super legal way. So I contacted Kristy simply because she’s a fountain of knowledge and asked her what I was legally aloud to quote, and she told me. And she said if I wasn’t sure, I could send it into Dragonsteel for review.

“Who would I send it to?”

“Me.”

So that made it pretty darn easy to get review eyeballs on it 😀

Would you like a chance to win a $10 Amazon Gift Card (1 winner) or a signed copy of the book (3 winners)? Follow the tour HERE for special content and a giveaway!

I am happy to be one of many tour hosts sharing information about