A Rough Guide To Castle Design – Part 1

In a series of articles by various authors we look at creating engaging settings for your games.

A Rough Guide to Castle Design

Part 1 – Who? and Why?

by Jon Roberts

In this article I’ll lead you through the design process I use to bring sense to my castle designs. It’s a process that puts reason into design, so that players’ questions have sensible answers. When a world makes sense to players they can imagine it, engage with it and use their heads to navigate its challenges.

There is of course a balance to be struck. If I spend too much time on the little details (how many pounds of meat a garrison of 20 need to store for the winter) then I’m not adding any value – that time is better spent on the evil villain’s master plan or creating truly fiendish traps to deter invaders.

To create a castle that makes sense, first we need to answer Why? and Who?


A castle’s purpose is usually defined by its location, its owner and local politics. In benign lands a castle might be a place of showoff luxury, of paranoid protection, a seat of power, a status symbol or a community focal point. In hostile lands it might be an essential safe haven or a point of hard power from which to dominate the surrounding lands. There are unlimited reasons for a castle but, if it’s going to make sense, we first have to think of one.


Who owns it? Who built it? Who’s necessary to fulfill the castle’s Why? Who else lives there? Together, the answers to Who? tell us the castle’s size, grandeur, construction methods, practical limitations and building materials.

The Why? and Who? of my example castle:

It is the seat of a minor lord who rules a medium sized farming community and small village. The village is tucked away in a mountain valley and the castle is a solid defensive structure at the valley mouth, protecting the community from bandits. The defended valley is relatively safe and few of the community and none of the livestock are housed within the castle. The castle is small; most of the servants come from the town and only important people and soldiers live in the castle itself.

A military outpost it would be very different; everyone needed to run the castle would have to live within its walls. A king’s castle in the center of a stable country would be built for comfort, rather than defence, its role more to impress than to hold off attackers.

Continue reading Part 2 – The Room List >>

One Response to “A Rough Guide To Castle Design – Part 1”

  1. While asking “Who?” and “Why?” is important often a castle has some history, and it makes things interesting. The whos and whys change with time.

    A castle built for luxury that is turned into ruins, then with makeshift repairs was a “military fortification” used by soldiers to protect nearby roads, but by now it is almost abaddoned, because the guards don’t have enough resources to protect the region…

    As you see the moment some PC acquire the castle we have 3 answers to who owns it…

    1st: A local noble lived here with some servants.
    2nd: Some guards lived there
    3rd: It is “seat of power” for the PC who got it.

    And some to why:

    1st: Some noble lived here and prefered a comfortable castle
    2nd: It seen some conflict and small parts of it redesigned for protection
    3rd: A makeshift camp for guards…
    4th: Soon lest guards and more captured criminals stayed there (not enough men to send them to the city)
    5th: It was slowly abaddoned, only some patrols visited them.
    6th: It was given to the PCs as a reward by a smart ruler.

    The PCs follow a good drow deity, and this way he rewarded them with land, and kept them away from cities where many would be afraid of the drow members of the party.

    So in addition to being a base of operation for adventurers, it also the place where they train followers… And they also use the castle as a place to represent a religion. Where people can learn about drow, see how followers of that religion are nice, etc.

    And back to who: Who built it? The original builders? Who modified it for defense? The guards with their changes and makeshift repairs? Or the people hired by various party members?