D&D 5E How do you do secret doors?

iserith · Apr 19, 2017

Prakriti said:
I'm running two Sunless Citadel games concurrently. Group A's highest passive Perception is 16, while Group B's is 12. Almost every trap and secret door in the adventure is DC 15. So if I use the passive Perception rules as written, Group A will find every secret door and trap, every time, and Group B will miss every trap and secret door, every time. That doesn't seem fun or fair.

That can happen if you're not telegraphing the secret doors when describing the environment. Possible SC spoilers follow.

I don't have Yawning Portal yet, but I did update Sunless Citadel myself and run it a year or so ago. Near the entrance, in the tower shell, is a trapped secret door leading to a small chamber. (I'm assuming this wasn't changed in the update.) I took the trap out, but knew I needed to telegraph the secret door in some way in the description. So I added one line to the boxed text: "Water seeps in along the southern wall." The secret chamber is described as "damp and cold," so this made sense to me.

Investigating the area of the water given no time pressure or other cost or risk reveals the secret door, no roll. "The water has no obvious source, pooling at a seam where the floor and wall meet. The seam runs up the wall, across and back down again, framing what may be a secret door." From there, the players can have their characters try to figure out how it works, the stakes of the Intelligence (Investigation) check being (success) the operation of the door is discovered quickly and quietly or (failure) it takes a while and is noisy which calls for a wandering monster check.

As you can see, if there is someone in the party undertaking the general task of Search for Secret Doors while traveling the dungeon, but does not have a high enough passive Perception, then yeah, he or she is going to miss this secret door. But if I have telegraphed its existence in describing the environment, the players have the opportunity to investigate more closely and discover it - and be rewarded for engaging with the environment.

Glomb175 · Apr 26, 2017

I don't have much experience with secret doors so feel free to disregard my comment, I just ran the redbrand ruffian hideout scenario from lmop for my group and in place of the secret doors, I replaced them with puzzle doors, inscribed with difficult riddles. That's just because I know my players and they don't investigate rooms, they see the entrance and the exit and they go straight through it so they'd miss out on some good opportunities if I didn't guide them

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Quickleaf · Nov 24, 2018

Resurrecting this thread, as there was good discussion on several related topics I consider connected (secret doors, traps, passive vs. active Perception, Investigation, and DM description).

I've often wondered about the specifics of a secret door's functioning & how to describe a secret door without obviously describing a secret door. There a fun little blog here about 20 modern-day secret doors: https://makezine.com/2015/06/17/20-secret-doors-clever-hiding-places/

The first one is a sliding/folding secret door bookcase on a track.

I was thinking about how I'd describe this kind of secret door to a player whose PC has a high passive Perception. And honestly, it really does look like a book case. A while back I mentioned giving traps the False Appearance trait of a mimic/gargoyle/treant, and I feel like this is a similar case. What would high Perception notice here? Maybe an unusual joint in the front face of the bookshelf? If it's poorly constructed, you could always have an arcing scrape extending along the floor from the middle of the bookcase?

So, I'm imagining a theoretical write-up for this bookcase secret door... Folding Bookcase Secret Door: False Appearance (bookcase); DC 15 Wisdom (Perception) you notice an unusual joint in the front-facing woodwork between the two shelves; DC 15 Intelligence (Investigation) the joint appears to opposite die of a hinging mechanism, as if the two shelves are meant to fold.

Not bad, but I was thinking about groups using the passive Perception technique with secret doors (i.e. if you're "above this high" you notice it). In many situations it really doesn't matter who succeeds the Perception check, much like when one or more PCs make a lore check; regardless, the knowledge usually gets disseminated among the PCs. So I've been wondering if there might be a technique to make it relevant who notices the secret door – like a reaction of some kind. We did this spontaneously a lot back when I played/ran AD&D or BD&D.

"You push the side of the bookcase and it begins to fold towards you, revealing a secret passage behind it... what do you do?"

Maybe if the player succeeded one of the checks (or had a high enough passive Perception), they have the option of using their reaction to prepare for whatever may be beyond the secret door... depending on the scenario, this might include thrusting a torch/lantern in the passage, drawing a weapon, ducking back behind the wall for cover, or casting a protective spell. This reflects the PC realizing the bookcase was some kind of secret door, as opposed to a player just having their PC push on stuff and then stumbling a bit when accidentally coming upon the secret door. So that gives me a writeup like this...

Folding Bookcase Secret Door: False Appearance (bookcase); DC 15 Wisdom (Perception) you notice an unusual joint in the front-facing woodwork between the two shelves; DC 15 Intelligence (Investigation) the joint appears to opposite die of a hinging mechanism, as if the two shelves are meant to fold; a PC succeeding either check or with a passive Perception of 15 or higher can take a reaction as soon as the secret door is opened to respond (e.g. duck for cover, draw a weapon, light or extinguish a light source).

5ekyu · Nov 24, 2018

Quickleaf said:
Resurrecting this thread, as there was good discussion on several related topics I consider connected (secret doors, traps, passive vs. active Perception, Investigation, and DM description).

I've often wondered about the specifics of a secret door's functioning & how to describe a secret door without obviously describing a secret door. There a fun little blog here about 20 modern-day secret doors: https://makezine.com/2015/06/17/20-secret-doors-clever-hiding-places/

The first one is a sliding/folding secret door bookcase on a track.

I was thinking about how I'd describe this kind of secret door to a player whose PC has a high passive Perception. And honestly, it really does look like a book case. A while back I mentioned giving traps the False Appearance trait of a mimic/gargoyle/treant, and I feel like this is a similar case. What would high Perception notice here? Maybe an unusual joint in the front face of the bookshelf? If it's poorly constructed, you could always have an arcing scrape extending along the floor from the middle of the bookcase?

So, I'm imagining a theoretical write-up for this bookcase secret door... Folding Bookcase Secret Door: False Appearance (bookcase); DC 15 Wisdom (Perception) you notice an unusual joint in the front-facing woodwork between the two shelves; DC 15 Intelligence (Investigation) the joint appears to opposite die of a hinging mechanism, as if the two shelves are meant to fold.

Not bad, but I was thinking about groups using the passive Perception technique with secret doors (i.e. if you're "above this high" you notice it). In many situations it really doesn't matter who succeeds the Perception check, much like when one or more PCs make a lore check; regardless, the knowledge usually gets disseminated among the PCs. So I've been wondering if there might be a technique to make it relevant who notices the secret door – like a reaction of some kind. We did this spontaneously a lot back when I played/ran AD&D or BD&D.

"You push the side of the bookcase and it begins to fold towards you, revealing a secret passage behind it... what do you do?"

Maybe if the player succeeded one of the checks (or had a high enough passive Perception), they have the option of using their reaction to prepare for whatever may be beyond the secret door... depending on the scenario, this might include thrusting a torch/lantern in the passage, drawing a weapon, ducking back behind the wall for cover, or casting a protective spell. This reflects the PC realizing the bookcase was some kind of secret door, as opposed to a player just having their PC push on stuff and then stumbling a bit when accidentally coming upon the secret door. So that gives me a writeup like this...

Folding Bookcase Secret Door: False Appearance (bookcase); DC 15 Wisdom (Perception) you notice an unusual joint in the front-facing woodwork between the two shelves; DC 15 Intelligence (Investigation) the joint appears to opposite die of a hinging mechanism, as if the two shelves are meant to fold; a PC succeeding either check or with a passive Perception of 15 or higher can take a reaction as soon as the secret door is opened to respond (e.g. duck for cover, draw a weapon, light or extinguish a light source).

It depends on circumstances...

If it's anything except a well kept up active location - cracks allowoping breeze, smells from other side, lights, even bugs or insects leaving signs of more activity at that point along the shelf - in the dust msybe. Mildew or mold perhsps.

If it is an active location, then maybe footprints or unusual signs of foot traffic.

MNblockhead · Nov 25, 2018

Some excellent answers here. I just want to address the common distaste many DMs have for Passive Perception. I think passive perception is fine if you run it as isereth describes above, but I would add that the passive perception is going to notice things that would easily be over looked that *could* be evidence of a secret door, or maybe it is just more recent construction or repairs.

I describe the environment and ask the players what they are doing.

"You force option the door to the ancient tomb. A 5' wide passage slopes down, continuing more than a 100' descending into darkness. What do you do?"

Maybe two characters quietly scout ahead, one focusing on traps and the other keeping a look out against undead or other potential attackers. Following along a ways back another character carefully checks for secret doors. The fighter and cleric take up the rear, keeping alert for anyone attempting to sneak up from behind.

As they move down the corridor, I describe the results of their activities. Instead of making them continually role for perception, they can use passive perception. For the player searching for secret doors, I may describe the passage as looking undisturbed an nothing seems out of place. Or maybe I state that they find an area where the morter has broken away, or some scratches on the floor, etc. The player can then investigate. Now many times, what there will be no secret door. This avoids having every passive perception result indicating a secret door. Maybe there is a secret door and you just can't figure out how to open it. Maybe there isn't one and it is just a stone that was damaged during construction. If you roll low on investigation, you won't be entirely sure.

This keeps players on their toes and engaged with the environment.

Also, I don't let everyone make an investigation check. Another character can help the character who made the passive perception check with the investigation, but to make a second investigation check, you have to bring something new to the table. Maybe the dwarf cleric, who wasn't looking for secret doors can make a second investigation using stone cunning to determine if the unusual grooves can be explained by construction practices or erosion, etc.

pming · Nov 25, 2018

Hiya!

Gaxkang said:
I'm gearing up to run Caverns of Thracia converted to 5e in the Summer and I really don't have an idea on how to do secret doors in a meaningful way. In the old days it was just a d6 roll whenever the party passed on, and I suppose the logical continuation of that would be a perception check now (or passive perception).

Er, no, no it was not. In the "old days", say B/X D&D from '78/81, you had to actively say "I search for a secret door...here" and point to the location on the map. It took 10 minutes to search a 10' square cube. Your chance of success was 1 in 6 (2 in 6 if you were an elf). If a party walked down a corridor with a secret door in it...they walked past it. There was ZERO chance to detect it unless the player(s) declared they were searching AND they searched in the right 10' area AND the DM rolled a 1 (or 2 for elves). Secret doors were very hard to find back in the "old days" (re: tomorrow, for me...

).

But something about that feels like its missing something, its not very robust and more than a little arbitrary. But in the same vein, every time I've tried to describe an area of the wall in such a way that hints at something being there, like "this part of the wall is covered in a newer looking coat of plaster, then the door is always found and its not very secret.

So how do you do secret doors? What ways have you tried that work?

I do it the "old way" still. If the players don't say "We search for secret doors...here", then they don't find it. When they do search, I use Perception and I roll the dice for them, behind the screen. My go-to DC for a 'normal' secret door is DC 18. IF a character succeeds with the Perception, I then place the "S" on the map in the correct location. Then the Players can each roll an Investigation check, again with DC 18, to locate the specific means of opening said secret door. In other words, just because they found it doesn't mean they know how to open it.

And yeah, this means Secret door often go un-noticed. Occasionally they will find one, but be completely stumped as to where/how it opens.

PS: For the whole "Passive Perception" thing, I often have 'variable DC' numbers for mundane/typical things (e.g., passing by a concealed door...a door/passage that is behind a large bookshelf in a room, for example). It will be something like "DC12+"; then, when a PC gets near it I roll d6 or d8 and add that to 12...that's the DC. It lets me set "average DC" numbers for mundane things, but still leaves it open to interpretation of 'quality' or whatever...and also keeps the auto-success/fail when a PC has a Passive Perception of, say, 15...they would always see a DC 15 or under Concealed Door. At least with a random number added on I can justifiably say "don't look at me, I'm just the DM" when they miss the Concealed Door and are attacked from behind with their only escape being deeper into the dungeon where they don't know what's there...

^_^

Paul L. Ming

Stalker0 · Nov 25, 2018

I get the concern about passive perception...it’s one of the things where you are damned either way.

If you go with passive...a party either auto succeeds or auto fails.

With rolling, due to the math of multiple characters rolling, the chance to spot goes way up...so you often have to raise the DC to compensate. And it takes more time.

Ultimately I go with rolling just because my players like the control, but it’s not a perfect scenario

Laurefindel · Nov 25, 2018

Stalker0 said:
I get the concern about passive perception...it’s one of the things where you are damned either way.

If you go with passive...a party either auto succeeds or auto fails.

With rolling, due to the math of multiple characters rolling, the chance to spot goes way up...so you often have to raise the DC to compensate. And it takes more time.

A poster above proposed a third possibility, and the more I think about it, the better I like the idea: the door rolls its own ability check!

[edit] that was @Shiroiken in this post

So instead of having a set DC, the door has some sort of "hiding bonus" (presumably set by the makers of the secret door) and when the PC walk in front of it, the DM makes a check for the door (DC = passive perception). If the check is successful, the door remains hidden. Otherwise, it is discovered. The DM even has the possibility of giving the door "advantage" if he/she wants to (covered in snow/dust, overgrown with vines and moss, etc).

This way, players don’t get a hint for rolling perception out of the blue (and get four attempts for a 4-player party), and passive perception is not always a auto-win/auto-lose.

Imaculata · Nov 26, 2018

What I usually do, is tell the elf in the party that he senses a draft, or something similar. I clearly telegraph a secret door if someone with keen senses is close enough to it, or if someone is deliberately looking for one.

But I think most importantly, I make sure that secret doors are always optional. They may lead to treasure that is not required for the completion of the dungeon, or they may open up a shortcut, an optional path. But they are never tied to progression.