Chapter 6: Experiments and Surprises
This chapter focuses on the theory of traps, hidden doors, and interactive features. As you go through these exercises, you’ll create hidden risks and rewards that careful players will be able to find through thoughtful exploration.
As we’ve progressed through this course, many of our activities have been focused on brainstorming. In chapters 6-9, we get more substantive and begin writing down features that we want to include in our dungeon. Later, we’ll decide where to place these features within our 30 rooms; we commit to keying the rooms in chapters 11 and 12.
Table of contents
Note
A course—by necessity—makes things sequential. The act of design is essentially non-linear. We put this section before the act of keying your rooms so that you can be thinking about the principles of disguising secrets as you progress. You’ll find secrets to hide throughout the design process!
Dungeon lore
As we discussed in chapter 2, a dungeon gets a lot of its juice from the contrast of what it was built to be contrasted with what it is now. The tension between these two truths drives much of the excitement the dungeon offers.
The contrast can be as simple as:
The Pyramid of Et was constructed by ancient kings to serve as their tombs. They are now abandoned.
But it can be more elaborate, too:
The House of the Tyrant was built by an ancient giant king. It is now occupied by dwarven bandits. They’ve looted all of the obvious treasure that they could carry or break down, but there are still titanic doors and colossal chests they can’t figure out how to access.
This lore isn’t an abstract exercise. Imagining dungeon features, hazards, and rewards ex nihilo is not only difficult, it’s pointlessly disconnected from the game itself. Your lore is what you use to generate ideas for the content of your dungeon.
- What original features of the dungeon have been forgotten by its current inhabitants?
- How do the current residents misuse the magical features of this place (for good or ill)?
- What secrets are hidden in the foundations of the dungeon?
- What traps, hazards, and puzzles exist to guard these secrets?1
Dungeon features
Fill your dungeon with interesting and fantastical things whose functions are unknown to the players (or even the dungeon’s denizens). These things are derived from your dungeon’s original purpose; magic and machines created by the original inhabitants for reasons now unknown. By experimenting with these features, players can learn their functionality (at least in part) and use it to their benefit.
The best dungeon features have both positive and negative effects. When used hastily, the players unleash and perhaps suffer the negative consequences. Once the feature is better understood, the players can use this dangerous element to their advantage. And, when used correctly, the feature can be employed to give the adventuring party a boon. For example, imagine a hydraulic press. If the players say “I stand under the column and activate the device,” they get crushed. But once they figure out its function, they can try putting all sorts of things under the press; they can use it to open chests, break cursed items, drain dragon brains from petrified skulls, etc. They can even start a Youtube channel about it.
Dungeon features for each letter of the alphabet
altar, book, cage, door, elevator, fountain, guillotine, hole (bottomless), idol, jewel, kiln, laboratory, machine, nega-magic field, oubliette, painting, quarry, rune, statue, throne, unholy shrine, void, well, X marks the spot, yellow sign, zodiac
Here are three example dungeon features for players to experiment with:
Mirror
A hall of twelve mirrors, three of which bear the frozen visage of an adventurer and three of which are broken. Those who look into an empty mirror see their own reflection frozen there. Adventurers who look into an empty mirror create a “save state.” At any point, they can choose to reset their bodies directly to this point—same XP, same Wounds, same equipment, etc. This must be done consciously, i.e., before they are unconscious or dead. When this ability is activated, the image disappears from the mirror and the mirror breaks.
River of Fire
The River Phlegethon looks like a normal river but the water is acidic, earning it the nickname the “River of Fire.” It exudes a noxious, sulfurous scent. Any normal item submerged into the waters is quickly destroyed.
Magic wall
An archway of skulls bifurcates a room. The keystone skull once belonged to a giant bird. A malicious presence haunts the bird skull, whose evil will only allow those who bear the tokens of its master the Pigeon King to pass. This is not a physical barrier but a mental command screaming DO NOT ENTER. It cannot be resisted by any sentient, living creature. Arrows and spells may pass under the archway.
The keystone skull’s evil will can only work on creatures it can see. Blinding the skull (with a flare spell) or sneaking past while invisible will also allow passage.
Traps and hazards
Traps are dangerous dungeon features designed to protect treasures and thwart intruders. For our purposes, “traps” include hazards of all sorts. A chasm in the dungeon with a rickety rope bridge that breaks if more than one adventurer steps onto it at a time is a good trap.
Traps are usually present to guard something specific. The presence of a trap will tell the players that there is something worthwhile to be gained by braving the trap. Gambling risk and reward is an interesting choice for the players.
We’ll perform the act of distributing treasure in chapter 9; earmark your traps as probable places to hide treasure for now.
As before, your lore will inform what these hazards look like and root them conceptually in the fictional space. For example, a giant’s trap might swing a crushing mace so high that it completely misses dwarves and shorter characters.
Tip
Remember the traps in Indiana Jones and the Last Crusade? You can set up puzzles that are based on your setting’s lore in the same way. Your setting’s lore will be remembered when it’s actionable and impactful.
Here are three example traps to surprise your players:
Flooding fish statue
A shallow pool hosts a large fish statue with a large blue sapphire in its mouth. Removing the sapphire causes the doors to slam shut and water to gush from the fish’s mouth. Within moments, the door will be completely flooded.
Why this trap doesn’t suck: A too-obvious reward should make players suspicious that there is a hidden risk. If the guild makes an effort to position themselves for success before looting the gem from the fish statue, they can significantly reduce the risk of this trap.
Chess board room
A 40’ x 40’ room with an alternating pattern of 5’ by 5’ white and black squares on the ground—like a gigantic chess board.
The guild can enter this room by any square on the front row. When they step onto a square, they hear a click.
The first square an adventurer steps onto magically marks them as a particular chess piece. That adventurer can only move through the room using legal moves for that chess piece. Stepping out of bounds results in electric shocks.
An adventurer stepping into the king’s square on the back row results in another click. A secret door adjacent to the king’s square opens, allowing the guild to exit into a new area.
Why this trap doesn’t suck: This is a more elaborate, more puzzle-oriented trap—the sort made by a mad wizard. This sort of thing can be fun when used judiciously.
Having no obvious exits to the room is a clue to the players that there’s something up. They have the choice to ignore the room or brave the trap if they want to figure out the room’s purpose (and find the secret door).
Because the penalty for learning the rules of the trap is just a wound, players have a grace period to experiment.
Invisible path
A door opens onto a chasm, apparently dropping into an endless pit. Falling into the pit would be certain death. On the other side of the chasm is another door.
In actuality, an invisible bridge spans the two doors, though it does not go in a straight line. Rather, it meanders across the gap.
Why this trap doesn’t suck: The danger is obvious and the solution isn’t. If the guild doesn’t understand there’s an invisible bridge, they can simply leave.
The presence of the invisible bridge can be found by reaching out and touching the empty air directly in front of the door. Adventurers can tap on it with a ten-foot pole or tentatively put their weight on the empty air while their companions hold a rope tied around their waist. The invisible bridge can be painted with paint, spilled ink, smashed lightning bugs, whatever.
My preview chapter of His Majesty the Worm, Dungeon Seeds, has many more interesting features and traps included if you need more ideas.
Writing “solutions”Advice
A defining feature of OSR challenges is that they have many possible solutions but no single solution. 2 Traps are great challenges because they present an obvious danger and aren’t easily overcome. They’re fun because players have the agency to avoid, disarm, or defeat the challenge using their ingenuity.
Create traps that aren’t just the purview of a single class, like the thief. Ideally, any player can participate in the fun of problem solving your trap by using a variety of character abilities, the content of their backpacks, and common sense. For example, a pit trap may have its mechanisms disarmed by the thief using their thief’s tools, but it may also be circumnavigated by the sorcerer’s gust of wind spell, or the party can simply jam a piece of furniture from an adjoining room into the pit so it can’t open fully.
When imagining solutions, don’t fall into the trap3 of thinking that these are the only solutions available. When adjudicating the players’ actions at the table, speak generously about what the adventurers can see and understand about the trap. Then, interpret the actions of the players fairly, imagining what would happen based on the physics of the world and hidden information that you understand. Let clever plans work.
On the other side of the coin, it is okay to invent traps with no idea of how players might get around the hazard that you’ve created. Players will surprise you with all the ways they can bypass even your most devious designs, assuming they have enough information to make informed decisions.
Secret doors
Some doors are hidden to explicitly exclude outsiders or guard treasure. Other hidden doors are original sections of the dungeon that have been papered over by the current residents, e.g., the giants’ quarters were too large to be used by the dwarven bandits, so they shut the door and forgot about it.
Place hidden doors in likely locations to give your players the thrill of exploration and discovery. You can put hidden doors:
- Behind tapestries and under rugs
- Inside sarcophagi or iron maidens
- Behind bookcases, triggered by pulling a certain book
- Behind waterfalls; in fact, all waterfalls must have secret doors behind them
Special doors
Some doors will only open at a certain time or state (the full moon) or when the players have performed a certain action (sacrificed a goat on the altar in the room). The cyclic loop of finding a door, not knowing how to open it, exploring to discover the special condition needed, and returning is part of the fun of fantasy adventure games. As before, let the lore of your dungeon guide and ground your choices for special conditions that are needed to open doors.
Make your dungeon doors interesting, regardless of whether they’re special. A door’s color can hint at what’s behind it. A door’s construction can show that it’s made to gate off a different section of the dungeon. Orcish graffiti on a door can give your players hints about secrets elsewhere.
Puzzler doors
A common type of special door is one that can only be opened once a riddle is answered or once a puzzle has been solved.
A good way to create puzzles and riddles is to look at examples that you think your players will know, and then twisting it so the answer is no longer obvious. “Reflavoring” a puzzle provides enough support because of the recognizable pattern that players can get it, but the newness makes it feel like a challenge.
Example riddle
Can we rewrite a riddle from The Hobbit? Everybody knows those.
A treasure chest
Hides what’s best
A golden treasure within
But open it once
And not even the wise
Can close the chest again
The answer, of course, is “egg.” You’ll see the little Humpty Dumpty reference I added in, too.
Example puzzle
We can reflavor a children’s game with a sword and sorcery pastiche to make a simple puzzle. I’ll use Hangman/Wordle as an example.
To open a magic portal, you must write the magic word. They see five blank spots that hold the letter runes of the magic word.
An adventurer who speaks Draconic may inscribe draconic letters to try and discover the magic word. If the letter is placed correctly, it glows green. If the letter exists in the word but is not placed correctly, it glows yellow. If the letter does not exist in the word, a single line of a pentagram is drawn.
If the players write the magic word (“BLAZE”) correctly, the portal opens. If all five lines of the pentagram are drawn first, a fireball erupts in the room.
Best practicesAdvice
Secret doors and puzzler doors carry risks. One of the risks is that they stop forward progress. Imagine a riddle that locks a door (“Speak friend and enter”). Until the players can guess the answer, the door will remain closed. If there’s no other way forward, play can’t happen! Another risk is that solving a riddle or puzzle might engage one player while the others sit at the table disconnected from the game.
The solution to mitigate these risks is to avoid using secret or puzzler doors to gate forward progress. Instead, use these challenges to guard optional content, like treasures. This lets players opt into a puzzle for an extra bonus, but also be able to disengage before the experience becomes frustrating.
Tip
In your map, look for “dead ends.” Set optional content or treasure in these dead ends, then gate them off with puzzling doors or traps.
CluesTheory
Traps and hidden treasures are staples of fantasy adventure gaming. However, they are difficult to do well in a medium like TTRPGs because hidden content is, well, hidden. It runs the risk of being inadvertently skipped, even by players who are trying to discover it. This can be frustrating to both players (who want to find hidden traps before they go off and hidden treasure to haul back to town) and GMs (who spent a long time thinking up cool hidden stuff)!
A key component of a game is meaningful choice. For a choice to be meaningful, the rewards and risks must be known (or at least discoverable). Therefore, an essential part of making hidden content is creating clues that demonstrate the existence of this hidden content: the risks and rewards for things that aren’t immediately apparent to the players. These clues are the parts of the game that the players can actually interrogate and interact with.
Think of hidden features like an iceberg. Much of a feature can be out of sight, but you must still be able to see part of it peeking above the surface.
“Landmark, Hidden, Secret,” Anne of DIYandDragons
Information can be landmark, or hidden, or it can be secret.
- Landmark information is automatic and free. Players hear landmark information the first time without asking, and if they ask, they can be reminded of it as freely as they heard it at first.
- Hidden information isn’t automatic - players have to ask to learn it. And it often isn’t free - there is often some fictional cost that must be paid to learn hidden information.
- Secret information has no guarantees at all. It is the opposite of automatic, and it’s always expensive. 4
Sensory clues
Clues can be embedded in sensory data. Describing unique or out-of-place sounds, smells, feelings, temperatures and other sensations to give players a hint that something is unusual and worth investigating. Layer descriptions from multiple senses to draw players’ attention to hidden features that are especially dangerous.
For example:
- A hallway with a noticeable draft from a hidden door
- Discoloration in flagstones to show a pressure plate
- Scorch marks and a lingering smell of burning to indicate the presence of fire traps
- An ozone smell and raising hairs on the adventurers’ arms to indicate a lightning bolt trap
Repeating pattern clues
Clues can be repeated patterns. The pattern will draw the players’ attention. Once they understand the significance, they’ll be able to apply their learnings to every room where the pattern exists.
Good clues aren’t immediately obvious on the surface, but seem obvious in retrospect—like the answer to a riddle
For example:
- Every mural in your dungeon has a secret door embedded in it. If the adventurers find a hidden door in one mural, a clever player might think to check the other murals for similar secret passages.
- There are four puzzles in this dungeon, each flavored around one of the elements. Once players understand that fire and earth have been key to solving two previous puzzles, they’ll be looking for a way to employ air and water in future puzzles.
Differentiated patterns
Clues can be created through differentiated repeating patterns as well. When one of these things is not like the other, your players will take notice.
For example:
- A row of four monkey statues: one hiding its eyes, one hiding its mouth, one plugging its ears, one making a rude gesture. If the players investigate the rudely gesturing one (the odd one out), they’ll find a cache of coins at its base.
- The room contains many two lit candles and one unlit candle. A secret door is revealed when all three candles are lit.
Broadcast dangers
The most important clue to broadcast is danger. It’s boring if a trap triggers while an adventurer walks down a hall, deals some damage, and the adventurer says “OK. I keep going, I guess.” Traps, like the rest of the game, should involve interesting decisions.
The greater the danger, the more clearly the danger needs to be telegraphed. If the trap triggered while walking down the hallway resulted in instant death instead of a small wound, the experience would feel even more arbitrary and unfair. If the hallway was smeared with blood and the adventurer still chooses to walk down it, they will be less surprised when they’re eviscerated by an instant death trap. The best trap clues make players say: “I should have seen it coming!”
Activity: Create hidden featuresActivity
In this activity, you will create hidden traps, treasures, and doors for your dungeon. Because your setting’s lore is a great way to define what these features look like, you will also decide the history of your dungeon.
For this activity, open the workbook that you created in chapter 2.
Steps 2 and 3 of this exercise reference the map you created in chapter 4. If you want, take a few moments to reacquaint yourself with your map on page 4 of your workbook.
Then, navigate to page 6: Traps and Secrets. For each step, write your answers down here.
If you want to see my version of the workbook with this activity complete, check it out here.
Step 1: Define your dungeon’s history
Imagine what your dungeon was constructed to be. Now, imagine what it is today, who occupies it, and what new purposes it serves.
Complete these two sentences:
- Once, this dungeon was…
- Now, this dungeon is…
Use the lore of your dungeon to inform your decisions in future activities.
Step 2: Create a secret door
In chapter 4, you designated at least one door on your map as secret by marking it with an “S.” Choose one of these secret doors to detail for this exercise.
In “Secret #1,” write a sentence or two for each of the following questions:
- Visible: What does the hidden door look like?
- Trigger: How is the secret door opened? Is it openable by pushing on it when it’s discovered? Is a specific “key” required?
- Effects: Is the door trapped? Is it magical in some way? If not, leave this section blank.
- Guards: What treasure, shortcut, or other benefit does the hidden door lead to?
- Possible Solutions: What clue in the room description will hint at the existence of the secret door? What can players see or interact with?
- Name: Rewrite “Secret #1” to be a memorable title for your secret door.
Is the door merely a nondescript section of wall? Is it hidden behind an object? Is it magically hidden? Is it a magic portal that appears after a certain action is taken?
Step 3: Create a special door
In chapter 4, you designated at least one door on your map as special by coloring the door a solid color. Choose one of these special doors to detail for this exercise.
In “Secret #2,” write a sentence or two for each of the following questions:
- Visible: What does the special door look like?
- Trigger: How is the special door opened? Is it based on an action taken by the players or something else? Is there a specific “key” required?
- Effects: Is the door trapped? Is it magical in some way? If not, leave this section blank.
- Guards: What is the door guarding? Is it designed to slow down intruders, give a special NPC exclusive access to a specific area, hide a treasure, or something else?
- Possible Solutions: What clue in the room description will help players understand how to operate the door? What can players see or interact with?
- Name: Rewrite “Secret #2” to be a memorable title for your special door.
Is the door just hard to open (heavy, hot, underwater, etc.)? Is there another object in the room that needs to be manipulated to open it? Is there a puzzle or a riddle needed? Does it open during a specific time of day/year? Can it only be opened by a specific kith/kin/gender?
Step 4: Create a trap or hazard
Last, you will brainstorm a fantastic hazard or trap to use in your dungeon.
In “Secret #3,” write a sentence or two for each of the following questions:
- Visible: Is the trap obvious or hidden? If it’s hidden, what clues telegraph the danger to the players? Is it naturally occurring or constructed by intelligent creatures?
- Trigger: How is the trap triggered? Is it based on an action taken by the players or something else?
- Effects: What does the trap do? How do you describe those effects mechanically?
- Guards: Why is the trap placed where it is? Does it guard a treasure, a faction’s stronghold, a tomb, or something else?
- Possible Solutions: What are possible ways that clever plays can avoid or disarm the trap? What clues can you write to hint to these solutions?
- Name: Rewrite “Secret #3” to be a memorable title for your trap.
- (Optional) Place the Trap on the Map: If you’re pleased with your trap, look at your map and consider where a hazard might make sense to be placed by the former or current inhabitants. Mark this area with a “T.”
Classic traps
alarm, arrows that shoot from the walls, boiling oil, collapsing floor, flooding room, jets of flame, poisonous mold, rolling boulder, swinging blades, unwilling teleportation
Further reading
Want a big list of fun ways to hide (and broadcast!) doors?
…secret doors are an excellent opportunity for OSR-style gameplay. A secret door is a common dungeoneering problem that is usually solved through observation and intuitive solutions (as opposed to system mastery, or having silver weapons).
Arnold K. of Goblinpunch wrote A Comprehensive Guide to Secret Doors, which is a thorough treatise on the subject.
Why do some traps suck? What are the pitfalls I should avoid?
Traps fall into two basic categories: zap traps and interactive traps. The difference isn’t the kind of danger, it’s how they work in play.
In Bad Trap Syndrome, Ben Robbins describes common pitfalls5 of standard traps in fantasy adventure games.
What are some good traps that I can use?
My measure of a good trap:
- At least one part of it is immediately visible.
- It allows interaction and investigation.
- it has impactful consequences for the victim.
Chris McDowall kicked off a conversation with his blog post 34 Good Traps about what makes a good trap in an OSR game. He lays out several open-ended, problem-solving traps you can use for your dungeon!
How do I create good clues for secrets?
I like games that eschew mental stats in favor of player skill. In short, that means no perception rolls or anything like it; if the players want to find something, they have to interrogate the scene (via the game master) to find what’s there.
Dungeon Scrawler’s Dungeon Room Appendix is a great resource for folks following along with this course as it lists and draws different rooms to include in your dungeon. Their treatise on secrets has lots of advice for where to hide things in your dungeon and creating clues to find them.
How do I use locked doors, hazards, and other features to create interesting flows through the dungeon?
One powerful technique is to show the players they haven’t unlocked yet right off the bat. Many metroidvanias do this in the first stage to establish the pattern of explore -> find a roadblock -> explore some more -> return to bypass roadblock.
Sometimes, I see the question: “How do I run an RPG like a metroidvania/like Hollow Knight/like Blasphemous?” Metroidvanias are a type of video game defined by large, open maps with many routes possible through them, with routes gated via utility-based powers. I wrote a blog post to talk through how these patterns can be used in an RPG as well. (There’s lots of relevant further reading linked from that post, as well.)
All spot art in this chapter (and this course!) by BertDrawsStuff. ↩
Citing Arnold K’s post 1d124 OSR-Style Challenges. ↩
Pun intended. ↩
Again, pun intended. ↩