Back when Dungeons & Dragons was about clearing out dungeons, there were some tasks that players performed in EVERY room they entered, more or less in this order.
- Search for traps / hidden monsters
- Loot the corpses of dead monsters (having killed them)
- Search the room for additional loot
- Search for secret doors / passages
To not do so was a dereliction of your duty as an adventurer.
When I placed a secret passage in the Gleaming Cloud Citadel, buoyed by my memories of first edition and AD&D, I was confident that my players would find it sooner or later. Instead, they marched inexorably down an endless corridor, blazing with a magical blizzard, happily gaining level after level of exhaustion, until – half dead – I offered them a roll to realise that they were caught in an extraplanar loop. They eventually retreated to safety, and yet, despite being stumped on how to continue, they still didn’t think to look for a secret door… luckily, an NPC I had planted, in the form of a ferret, was able to reveal their oversight by sniffing at a crack in the wall, and the adventure continued.
When it came to my final published version of Gleaming Cloud Citadel, I replaced the featureless hidden door with a riddle written on a 5 foot wide plaque. It reads:
Follow the right or left path to reach the end. Here a metal door will help you ascend.
The end in this case is death (down the aforementioned endless corridors), and ‘here’ refers to the plaque itself. The plaque is an illusion, through which they can pass to find a staircase leading to the tower’s next level. Riddles can also prove an adventure-halting stumbling block, but they’re better than a hidden door in that at least the adventurers know that they hold the key to continuing – the riddle – and now they need to solve it. An unsearched for hidden door is not even on the players’ radar and will just cause frustration and wasted game time (note: I also dropped a fairly big clue on how to solve the riddle in the location as well, in order to hedge my bets!).
So with the flaws of my original, neglected secret door in mind, let’s explore the topic further and see if we can’t master our design and running of this classic element of RPGs for future adventures:
When to Use Secret Doors
So, if we shouldn’t use secret doors and passages as the only means to continue an adventure (or at least a 5e adventure – maybe if you’re playing OSR style games you can still go ahead!), when can we use them? Well, I believe the best way to use them is as a reward for those curious adventurers who enjoy the ‘exploration’ pillar of D&D. Such rewards might include:
- The chance to bag extra loot
- The opportunity to shortcut the dungeon / location (thereby skipping encounters and conserving resources)
- The opportunity to spy on / surprise the enemy
All of these rewards are nice bonuses for the players, but none of them are the only way for the players to succeed in their current endeavour. In other words, allow for your secret passages to take the adventure in different directions, but never include them as THE only direction. When designing your D&D adventures just ask yourself: “What happens if the party don’t find this door?” If the answer is the adventure grinds to an awkward halt, then you might want to reconsider your design.
How to Run Secret Doors
The way secret doors are typically run (in my experience) is someone says: “I search the room” (either specifically for secret passages or else a general search) and an Investigation check either reveals, or doesn’t, the presence of the hidden door. (Note: Passive Perception might also reveal the presence of a hidden entrance, but I personally don’t favour PP for this usage… no doubt the topic of a follow up post!).
Such a check is fine for quick and dirty gameplay, but rather basic IMHO. Finding a secret door in some of our favourite books and movies tends to be quite a powerful scene: it typically involves a careful search, a bit of astuteness from the protagonist, and then the suspenseful moment when the door slides open and we are unsure of what’s behind it. It’s also usually a pretty cool moment. Who doesn’t like a rotating bookcase, sliding wall panel, or hidden trapdoor?
So how can we recreate the suspense, mystery and magic of that scene in our RPG games? For me, the first thing we can do to make finding secret doors more interesting than a simple skills check is to split them into two challenges:
- Finding the door
- Working out how to open it (finding it’s ‘trigger’)
This door is already starting to feel a lot more significant. After a successful Investigation check, the DM can reveal “you find a gap in the stonework that suggests a presence of a hidden door” and then either ask the players to roll another check to find the trigger, or – better yet – just have the players describe how they attempt to open the door. Naturally, for this to work, you should have already decided what the trigger is (pressure plate, hidden lever/button, password, riddle etc) and you can let the PCs describe their search.
We can improve our running of secret doors further, however. What if, instead of the players’ Investigation revealing the presence of a secret passage, it just revealed a hint at the door’s existence? “You notice that one of the floor tiles next to the wall has a sheen about it, similar to those at the room’s entrance and centre.” This should be enough for a smart player to deduce that the tile is often stepped on, meaning it’s likely there is a secret passage hidden in the wall it’s adjacent too. It’s a subtle difference in gameplay, but just allowing the players to make that deduction, instead of handing it to them fully baked, makes for a more satisfying gaming experience.
We can apply a similar principle to the second part of the challenge: working out how to open the door (finding the trigger). Whether you run this as a roleplaying challenge, during which players explain how they interact with the room’s objects, or as a skill check, or both, just hold back a little with what you reveal. If they examine the torch sconces, the might notice one juts out a little further than the other (you don’t have to say, ‘you pull the one on the left and the door slides open’). If they examine the statue, they might notice that it seems to be hewn out of a single block of marble, except for the right arm, which seems to have required a second piece of stone to carve. Now they have to decide how to use this information and also consider the possibility at least that they are about to trigger a trap, instead of a secret door. Always a nervous moment!
In both cases, instead of revealing the actual door and trigger, you can reveal a clue that should allow the PC to make the deduction “hey there must be a door here”, which is way more satisfying.
After that, you can add tension to the scene with some descriptive narrative of ‘the clank of concealed metalwork’ and then ‘the grind of stone on stone’ as a passage cloaked in pitch darkness is slowly revealed, and ‘a waft of dank cold air hits your nostrils’. Etc. etc.
Types of Secret Door
- Sliding wall (or floor)
- Rotating bookcase
- Fireplace with sliding back
- Wardrobe with false back
- Disguised trapdoor
- Hidden trapdoor (below a rug or piece of furniture)
- Rotating painting (or passage concealed by painting)
- Mirror portal / illusion
Clues Revealing a Secret Door
- A crack in the stone
- A faint breeze / draught in the room
- Different colour / texture stonework
- Scuff marks leading to nowhere / blank wall
- Furniture that is clearly frequently moved
- Sounds from beyond the door
- Hollow sound when tapped or stepped on
- Disturbance of dust
- Footprints / soil / mud
- Torn scrap of cloak
- A person who recently entered the room is no longer there
Triggers can be divided into two types. A simple lever or button you need to push, or a code or puzzle you need to know or solve to open the door:
- Hidden button or pressure plate (must be pushed)
- Disguised button or pressure plate
– a specific brick / tile
– eye / nose of a statue
– a book
- Hidden lever or knob (must be pulled or rotated)
- Disguised lever or knob
– torch sconce
– stone symbol you have to twist
- Rope or chain (must be pulled)
Coded / puzzle triggers:
- Button(s) or lever(s) that must be pressed in a certain sequence (three times in quick succession etc).
- ‘Key’ required, such as placing a medallion in the hollow of a relief
- Password required
- Door has question or riddle subtly inscribed on it (the answer to which is the password)
- A puzzle must be completed for the door to open (good dungeon door, but not practical for an NPC who wants to make a quick escape).
- A certain tune must be played (there’s an organ in the room)
- A water basin or chalice must be filled (it drains away after, allowing the door to close again)
- Statuettes / books / objects must be arranged in a certain way (although this raises the question of how the door closes afterwards!? It might be that the door opens for one minute and the user should un-arrange the objects before stepping through).
With the triggers that require entering a code / password you will mostly like want to leave a clue for what the password is, or have the password be obtainable (via a discarded scrap of paper etc), maybe in a separate room – the reward for a separate Investigation check.
A quick reminder then of the takeaways from this post…
- Avoid including a secret door as the ONLY way to continue an adventure
- Put rewards behind your secret doors (more loot, info, or shortcuts) instead
- Make secret doors a twofold challenge i) finding them ii) opening them
- Offer clues that let the players make deductions (and feel smart!)
I think that’s it!
More DM’s Tips
Check out some of my other posts about running the game: