Urban Fantasy Worldbuilding

This has been an insane year. And I mean that quite literally. I've published a non-fiction book, I've launched a Kickstarter, I've started a shop on my website, I've made the short list for a novel competition (This one: https://flash500.com/short-list-novel-opening-2025/ My entry is Blood and Bloom in Las Vegas)

And it's that last event (Blood and Bloom making the short list) that inspired this blog post.

Urban fantasy lives at a fascinating crossroads. It is fantasy that insists on standing inside the real world, but then asks: what happens when magic intrudes?

In this post, I want to explore two closely related pieces of craft in urban fantasy worldbuilding:

1. How you structure the world itself , and

2. How you design plots (especially mysteries) inside that world

I’ll use Blood and Bloom and my experience with it, alongside fantasy touchstones like The Dresden Files by Jim Butcher.

What Is Urban Fantasy, Really?

Urban fantasy is fantasy set in a real city that exists (or existed) in the real world. That distinction matters.

• It doesn’t have to be contemporary (Victorian London counts).

• It does have to be urban.

• And it does have to intersect meaningfully with real-world structures: police, media, governments, infrastructure, history.

This is why Harry Potter and Percy Jackson aren’t urban fantasy. They’re contemporary fantasy, but they're simply not urban.

Urban fantasy is about the city and the city should matter as much as any other piece of worldbuilding in book. Magic rubs up against zoning laws, crime scenes, tourism boards, journalists, and autopsies.

In Blood and Bloom, the opening image is a police crime scene on Lake Las Vegas, with flashing lights, forensic techs, and a body that should not biologically be doing what it’s doing. I use the city (Las Vegas) and have my character interact with the real world (the police), while still having magic (guy is dead with a bunch of flowers growing out of his chest).

Now, in Blood and Bloom, my protagonist needs to keep the magical world secret from the real world. And that brings us to the three models of Urban Fantasy & Magic:

The Three Models of Urban Fantasy Worlds

1. The Secret World

This is the classic model.

• Magic exists.

• Most humans don’t know about it.

• Everyone involved is invested in keeping it secret.

The Dresden Files is the gold standard here. Humans are treated as a nuclear option: weak individually, terrifying collectively. The fear isn’t that monsters will destroy humanity—it’s that humanity will respond.

Worldbuilding challenge: How is the secret maintained?

Your options include:

• Mystical obfuscation (glamours, perception filters)

• Bureaucratic cover-ups (special police units, classified files, disinformation)

• Social contracts (oaths, pacts, mutual assured destruction)

Mystical solutions make spectacle easier, but they reduce tension. Non-mystical secrecy raises stakes. Every witness matters. Every journalist is a threat.

In Blood and Bloom, Lily Harper is a sentinel and her job is not justice, but containment. The murder victim deserves answers, but preventing the fairy Pact from collapsing matters more. That moral tension only works in a secret-world model.

2. The Open World

In open urban fantasy, magic is public knowledge.

Everyone knows demons exist. Everyone knows mages rule. Society has adapted.

The Bartimaeus Sequence is a strong example: an alternate-history London where magicians openly dominate society.

Worldbuilding challenge: You must understand real history before you break it.

If magic had always existed:

• Would democracy arise?

• Would monarchies persist?

• Would policing, warfare, or class structures look remotely familiar?

Open worlds demand rigorous historical logic, combined with strong What If logic, because readers will interrogate every divergence.

If you want to create that kind of world, check out my conversation with George from Alternate History Hub.

3. The Recently Revealed World

This is the transitional phase. Magic was secret. Now it isn’t.

This model thrives on:

• Culture shock

• Moral panic

• New economies

• Extremist reactions

Laurell K. Hamilton and the Anita Blake books are a great example of this, with Vampires having become citizens with rights 2 years before the book opens. The Sookie Stackhouse novels (adapted as True Blood by HBO) is another sterling example.

Worldbuilding challenge: Can bring up all kinds of messy themes. Be aware of what you're doing.

Okay, so that's the world, but a world does not a story make. So let's talk about mysteries.

Why Urban Fantasy Loves Mysteries

Urban fantasy and mystery are natural partners because:

• Cities generate crimes.

• Secrets generate lies.

• Magic complicates evidence.

Mysteries thrive where information is asymmetric and that’s exactly what urban fantasy provides.

The easiest way to design a mystery is the plan your plot from the villain's POV and then insert your protagonist to discover clues. You can see this kind of structure in Storm Front (Book 1 of The Dresden Files) where the villain (Victor Sells) has agency at the start and Harry Dresden reacts to the plot. He follows damage, figuring stuff out, and only after he's got a reasonable idea of what's going on does the agency shift from the villain to the protagonist.

This same structure appears in Blood and Bloom:

• A body appears.

• Then a high-court fairy shows up

• Then a sword goes missing.

• Lily runs around like a headless chicken for quite a while, gathering clues on these events until she finds out enough to actually being protagonist-ing.

Let's take a look at 4 core principles of this kind of plot.

Crafting a Fantasy Mystery: The Core Principles

1. The Villain Has Agency

Your antagonist is already acting when the story start. The protagonist is catching up. Victor Sells is already killing people when Storm Front begins. The powers behind the Vegas murder are already moving long before Lily arrives at the lake.

2. Your Protagonist Needs Personal Stakes

In urban fantasy, the mystery should threaten:

• Their job

• Their identity

• Their safety

• Their relationships

Lily isn’t investigating because she’s curious. She’s investigating because:

• A Pact breach could start a war

• A fairy relic could destabilize the city

• Exposure could get innocent people killed

3. Clues Arise Naturally, Not Through Plot Convenience

Urban fantasy mysteries work best when clues come from:

• Crime scenes

• Institutions (police, hospitals, morgues)

• Allies with limited perspectives

• Magical tools with costs

4. Obstacles Are Not Delays. They Are Pressure

Interruptions matter. Allies get hurt, authorities interfere, rivals arrive early. Don't look at these events as padding. These kinds of delays are escalation and compression points that increase tensions.

Why Setting Is the Silent Protagonist

Urban fantasy cities should not be interchangeable. In Blood and Bloom, Vegas matters. It's a city of illusion, like some kinds of magic. It's a city in the desert, but there is water that plays a central role in the mystery of the plot. It thrives of excess, secrecy, and spectacle and that's part of the story.

A magical murder in Vegas means something different than one in Boston or London. The setting shapes:

• Who notices

• Who profits

• Who looks the other way

Urban fantasy worldbuilding succeeds when the city itself participates in the plot.

Build Forward, Not Sideways

Urban fantasy asks you to do two hard things at once:

• Respect the real world

• Break it intelligently

It is however one of the most rewarding genres in my opinion. And one which, if done right, has a very low barrier to entry, even for non-fantasy fans.