Designing a Fantasy Castle in Fantasy Worldbuilding Knowledge Base | World Anvil

Designing a Fantasy Castle

What’s the attraction of castles? Why do we as storytellers keep coming back to them?


Castles are the physical representation of power and authority. It's where things happen. It's a military place, but it's also sort of a dominant bit of architecture in the landscape. It's a hub of politics, money, military power. And so that makes it a hub for stories.


It's also a really good seat of internal drama. If you're doing political schisms behind castles, you have the upstairs and the downstairs. You have things overheard. All those stories come together in a limited space. You are forced by the power dynamics of the castle to be nice to people you would not be nice to otherwise. This is why intrigue thrives and spying and romance and politics happen there. Because you can't just kill each other on the castle grounds, much as you might like to.


Castles are also physical history.


They are what an archeologist would call "sites of multiple habitations." In the real world, that might look like a castle that was on a defensible hill, where the layers of habitation might be a Roman fort, that was replaced by a medieval chieftain's structure, that was expanded by a noble during the Renaissance, and then given a new facade during by a 19th century politician. But in a fantasy context, you can make those layers more interesting. Maybe a dwarven merchant acquires a castle built by elves with delicate architecture, and decides they can't build a proper fortress. So he rebuilds it his way, and later the elves visit and are horrified at how he's "ruined" the place.


Where to Place Your Fantasy Castle


One of the most common mistakes worldbuilders make is putting them on a map in random spots where they feel like it would be great to have a story-shaped castle. There are two obvious places where castles should go on your map. The first is on top of a hill. Yes, this is partly because it's easier to defend against a seige. But also, it's a status symbol. The ruler of an area wants to be literally above their subjects.


The other common place to put a castle is in a militarily significant place: a bridge, a crossroads, or river. In this situation, the ruler is seeking control of a strategically-important location. Two real world examples of this are the White Tower, which controls access to London via the Thames, and Stirling Castle, which sits between a marsh and a mountain on the passage to the north.


What Rooms Should a Fantasy Castle Have?


Based on what you see in movies, you might think that every castle consists entirely of a wall, a courtyard, and an audience chamber. But naturally, there's also a castle kitchen. There are stables. There are also living quarters - which might be for the nobles and servants, but could just be a garrison or barracks, depending on the purpose of this particular castle.


Crypts or dungeons beneath the castle are great storytelling options. They're dark, spooky and provide an entry point to adventure. Towers are also rooms with rich storytelling possibilities. Who is being held prisoner in the tower, and why? If your characters must climb the tower to rescue a prisoner, it's a powerful symbolic moment of subverting the authority that tower represents.


And don't discount that audience chamber or throne room. This is the interior showcase of status and power, and in a fantasy castle setting, it's where you can really go crazy and have fun with the height of "magical interior decorating." What represents opulence in your world? What kind of diplomacy, justice and rulership happens in this place?


Tips for Fantasy Castle Layout Design


Okay! Now you know what purpose your fantasy castle is serving in your game or story. It's time to start thinking about the actual layout. You can't create a battle map or any other visual reference if you don't know what you're drawing. So here are some tips for coming up with your "construction punch list" of structures, rooms and spaces to include in your fantasy castle layout.


Work from the outside in.

  • What is the first element of your castle that characters visiting it will see and encounter? The towers? A moat? Or a ditch filled with spikes and refuse?
  • How many towers will the castle have? Will they be round or square? How tall are they? What condition are they in?
  • What image does the castle present: military might, wealth and power, or history and heritage? These might be represented by heavy fortifications, gleaming banners, or restoration work.

Work from the present to the past.

  • Think about those layers of habitation. What is the castle's current use? Is it a seat of justice and diplomacy? The showplace of a frivolous noble? These might dictate including ballrooms, dining halls, military garrisons, or other structures.
  • Who was the previous owner of the castle, and what was their use for it? What lingering structures speak to that history? What condition are they in now?
  • Is there a lost history to the castle? What ancient or mythic characters used this place as a base of operations, and what elements of their presence remain?

Layer in fantasy elements as you go.

  • If you're building that fantasy moat, what monsters are enchanted to inhabit it? What other magical defenses exist?
  • Is there a court wizard? What kind of spaces would he or she need - an orrery, library or tower? Would their presence be secret or showcased in your setting?
  • Have these rulers used magic in place of modern technology? What conveniences do they have access to that ordinary folk wouldn't? Magically-heated baths? Enchanted birds to send messages to the market down in the village?


  • Kobold Press Campaign Builder: Castles & Crowns This fantastic resource from Kobold Press is now in pre-order, after a successful Kickstarter, and is compatible with DnD5e and Tales of the Valiant.
  • AD&D Castle Guide - This old school resource includes a lot of background on medieval castles, as well as "a modular system for the design and construction of castles for use by player characters and NPCs alike."
  • Roll for Fantasy - Castle Creator - This allows you to create a relatively simple, (mostly) 2D view of a castle. (Their town creator can be used to create a top-down view).