Doors in the Dungeon

What makes a door? And moreover, why should we care?

May 02, 2025

A few months ago, I wrote that the most important thing to know about a dungeon is its theme. I stand by that logic, as it distills into many different aspects of the dungeon such as monsters, history, environment, etc.

But there’s another thing that I would wager is as important, which are barriers.

And by that, I mean doors.

To be a little loose with the description, a door refers to any movable barrier that allows (or disallows) passage. Traditionally in TTRPGs, we tend to see doors in the following configurations:

Plain Doors

It's pretty much what it says on the tin: it's a door. It opens. It closes. It can be made out of wood, stone, metal, beads on string, or whatever.

We can do better than that, though, can’t we?

A plain door can have carvings that describe the dungeon’s inhabitants or some historical event. They can be marked by ongoing situations in the dungeon, such as being charred or having messages scrawled on them.

In short, a door is never just a door.

Locked Doors

Fundamentally, if we simplify a locked door to “any movable barrier that bars exit or entry until some prerequisite is met”, a locked door can also be a stuck door, a barred door, a magically-warded door, a portcullis, etc.

Once we open the definition to those potential other scenarios, we start to see the opportunities for doors that don’t just require a key or an exercise in lockpicking.

Secret Doors

One of the trickier things to run in a dungeon is how a secret door is detected by the group. In a lot of games I’ve played, the door either goes completely unnoticed or is just given to the players via some passive ability.

However, the trick to secret doors in my experience is to offer a strange description of something that acts like a little needle to prod the players’ attentions.

Saying something like there are scuff marks on the stone floor in front of the bookcase does a good job of highlighting something that would absolutely be noticed without outright giving the solution away.

The key to secret doors (pun intended) is that you actually have to give the information up to the players. We’ll talk about transference from GM to player in another article soon.

Trapped Doors

Lastly, and probably most controversial of the door tpes, are trapped doors. These barriers often have some sort of mechanism attached to them that harms or otherwise creates a setback for the players.

Now, traps are a lot like secret doors in that the players actually need to know the clues before they can think to investigate it. And it makes sense to provide these clues freely, as a trap is often pretty noticeable if you were to simply open your eyes and look.

In my opinion, traps shouldn’t be incredibly difficult to disarm either. Unless you’re playing a game where it is a very particular skill assigned to a very particular class (looking at you, BX), you can offer the solution to the players freely without any sort of check — the only cost will be time.

How to Actually Use Your Doors

One of the most important decision points in mapping a dungeon as a GM is where separate rooms (or encounters) connect to one another. From a non-narrative perspective, the easiest connectors are doors (followed closely by hallways, but those are a whole different beast — another future article!).

That means that anywhere you want rooms to connect, think about what kind of door would lead from one room to another.

Would it make sense for a trapped door to exist between the gathering room and the waste room in the goblin den? Probably not, unless goblins are eager to do minor puzzles every time they need to take a leak.

Similarly, think about when a door is supposed to be a vehicle for other information — such as murals, graffiti, or just a plain sign.

Or what material the door is made of, whether its stone, wood, metal, or even crystal.

Whatever you decide to do with your door, it should feed into the overall theme of the dungeon and should serve as an evocative challenge or detail about the place as a whole.