I’ve been thinking about hidden s$&% lately. And by lately, I mean over the last several months. All of that bulls$&% with time pools and core rules, that all started because I wanted a way to handle hidden things in Dungeons & Dragons better. Hidden things made me think about stealth. Stealth made me wonder about different modes of play. And different modes of play led me to wonder whatever happened to those modular extra rules that Wizards of the Coast promised as a way to convince us not to be mad about having to drop $150 on the same books we’d already bought numerous times just because there was a bigger number on the front.

Point is, I’ve been thinking about hidden things in D&D adventures. See, I play a lot of exploration-based video games. I LOVE hunting for secrets. And I’m drawn to games with lots of s$&% to find: hidden treasures, collectibles, audio and text logs, secret passages, all that s$&%. Hell, the last three games I played obsessively to completion were Alien: Isolation, Doom and Prey.

Hunting down hidden s$&% – let’s call it scavenger hunting – scavenger hunting should be an awesome part of Dungeons & Dragons, right? I mean, Dungeons & Dragons has a lot of exploration built right into it. And finding hidden s$%& is pretty much THE payoff for exploration. And yet, in this, D&D kind of sucks.

As I’ve said before, my goal is to develop a comprehensive set of modular rules that allows the GM to hide s$&% in adventures for the players to find. In a FUN way. Not a sucky way. But before building a pile of new rules, it’s important to understand a couple of things. First, how do the OLD RULES actually work and second, how SHOULD the new rules work conceptually.

Today, we’re going to look at the first of three types of things that GMs might hide in their adventures and answer those questions. We’re going to look at traps. How do they work right now in D&D? And how should they work?

No One Reads Anymore

Last week, I discovered that no one knows how traps currently work in D&D. See, I did one of those Twitter polls I sometimes do. This one was about the difference between Intelligence (Investigation) and Wisdom (Perception). Specifically, I asked people to tell me how they – as GMs – determined when to use one of those skills over the other. I got a lot of different answers, but almost all of them boiled down to a simple dichotomy: Perception was for passively noticing something, Investigation was for actively searching for something. When someone walked into a room with a trap, for example, they had a chance to spot that trap outright. That was determined by either Passive Perception or a Perception check. And if the character searched the room for traps, the outcome was determined by an Investigation roll.

Either way, the result of a successful check was the same. The GM would tell the player about the presence of the trap and invite them to disarm it.

The distinction between spotting and searching isn’t new to D&D. It appeared in D&D’s 3rd Edition. 3E included two distinct skills: Spot and Search. And they were used as described above. One was for casually noticing stuff, one was for actively searching for stuff. Spot was based on Wisdom, being more reliant on awareness. Search was based on Intelligence, being more reliant on deduction and inference.

Side note: that distinction is stupid.

With the culling of the skill list in D&D’s 4th Edition and with the addition of Passive Perception, there was no reason to have two separate skills anymore. Passive Perception covered the spotting, and an active Perception check covered the searching. And that made a lot of sense. The distinction between spotting and searching, after all, is really about the distinction between actively and passively using your senses.

When D&D 5E added the Investigation skill under Intelligence, it seems like lots of folks assumed that they were just bringing back the Spot/Search distinction. But that would have been a really dumba$% thing to do. Now, WotC does do a lot of dumba$& things, but this wasn’t one of them. It turns out, if you actually f$&%ing read the rules, Investigation is not anything like searching at all. Searching and spotting both fall under Perception skill. Investigation is different. The problem is, to really understand the difference between Perception and Investigation, you have to read PHB 177 to 178 – including the sidebar on Hidden Objects, DMG 103 to 104, and DMG 120 to 123. And then you need to ignore a few unclear phrases and some outright contradictions. But if you do that and put it all together, you’ll actually a clear picture of the distinction between Investigation and Perception.

Perception is for discovering sensory information. Anything you can see, hear, feel, touch, or taste. Under normal circumstances, you don’t need to roll any dice or compare any numbers. You see what you can see and hear what you can hear. But occasionally, sensory details might escape your notice or they might be hidden from you. Some things are tiny and easily overlooked. Some things are quiet and not easily overheard. And some things are camouflaged or concealed or disguised.

In those circumstances when something might go unnoticed, the GM uses Perception to determine whether any of the characters notice it. First, the GM sets a DC. Then, the GM compares the DC to each characters’ Passive Perception. If a character’s Passive Perception is equal to or greater than the DC, the GM reveals the detail. Otherwise, it goes unnoticed. However, a player who suspects there might be something hidden can choose to search for it. In that case, the player rolls a Perception check against the same DC. And it should be noted that, according to PHB 178, the player is REQUIRED to describe where they are searching and what they are interacting with.

So, if Perception covers both passively spotting things and actively searching for things, what is Investigation? Well, Investigation is for making deductions based on clues. But you could be forgiven for not understand what that actually means. The description of the skill on PHB 178 isn’t very clear and it outright contradicts some of the specific uses for Investigation described in the other citations I listed. But it’s those other citations that actually make it clear. And, in D&D, specific beats general.

Investigation lets you reach conclusions based on sensory information, but – and this is important – that sensory information must already be available. Despite what the skill’s description says about “searching for clues,” those clues come from Perception. The example given in the book of using Investigation to determine what kind of weapon might have inflicted the fatal wound on a corpse bears this out. The sensory information – the wound itself – is obvious. No Perception roll is needed. And the reference in the description to “deducing the location of a hidden object” is directly contradicted by the sidebar on the very same page, as well as in the DMG several times.

The DMG actually provides some clear examples of when and how to use Investigation. For example, after you notice the strange breeze and misplaced seam in the wall that doesn’t line up with the masonry using Perception, Investigation allows you to deduce the existence of the secret door and figure out the mechanism that opens it. And after you notice the treasure chest is bolted to the floor and there are strange holes in the wall behind the chest as part of an elaborate mural, Investigation allows you to figure out how the arrow trap works well enough to sabotage it.

That means that the GM must draw a clear distinction between sensory information and deductions based on that information. That is, the GM shouldn’t say “you discover an arrow trap” or “you found a secret door,” as the result of a successful Perception check. Instead, the GM must limit himself to describing exactly the details the character noticed that might lead to those conclusions but not the conclusion itself.

Of course, after failing an Investigation check on further examination of those sensory details, the players could still guess what those details mean. At least in some situations. If the players notice the seam and the breeze and the bookshelf, they might just guess that there is a secret door and it is opened by moving one of the books. And then the characters might simply try to move all the books. And all the torch sconces. And anything else. That’s fine. There’s nothing wrong with that. Especially because, in some situations, they might guess wrong. What appears to be a secret door might actually be the mechanism for a trap. Perhaps a panel that slides open and allows a swarm of ravenous spider-rats into the room if the players disturb the books. They might regret their attempts to open it.

The GM must be mindful that these rules create three tiers of hidden information. First, there’s information that is obvious, but requires interpretation. That’s information that requires only an Investigation check: “what weapon inflicted the deadly wound.” Next, there’s information that isn’t obvious, but requires no interpretation. That’s information that requires only a Perception check: “there is a small, folded note hidden in the victim’s boot.” Finally, there’s information that is not obvious and requires interpretation. That’s information that requires both a Perception check to turn up the sensory details and an Investigation check to understand the results: “there is a tiny, discolored pin prick on the back of the victim’s neck; he was jabbed with a poisoned needle.”

Now, I have to admit I might be wrong about all of this. As I said, the books are a bit unclear and slightly contradictory. I’m guessing at what the designers SEEM TO HAVE INTENDED. And it’s entirely possible that I’m wrong. Hell, some of the details suggest that WotC themselves aren’t entirely clear on what they intended. Honestly, the fact that I can deduce an actual pattern from this s$&% might be a fluke. The designers themselves may have just said “f$&%ed if we know!” And given that the core of the distinction seems be hanging on the increasingly arbitrary, bulls$&% distinction between Intelligence and Wisdom, who f$&%ing knows at this point.

But here’s what I do know: the distinction that I THINK was intentional, the one I described? Personally, I think it potentially leads to a better game than the old Spot and Search distinction. Especially when it comes to trap mechanics. So, let’s get back to those now.

How Traps SEEM to Work in D&D 5E

To be fair, the DMG is pretty clear about how traps work. Seriously. Check out DMG 120 to 123. It’s all there. The problem is, for some reason, the geniuses at WotC decided to present specific rules for each specific trap rather than general rules for all traps. I don’t know why. There does seem to be a general pattern that could have been spelled out more clearly and there is a prose discussion that tries to spell out some general rules. But some of the specific traps deviate from the general form.

A trap consists of two parts: a trigger and a terrible thing that happens when the trap is triggered. Let’s call that the effect so I don’t have to type out “terrible thing that happens when the trap is triggered” over and over again. A trigger might be described as a specific device, like a tripwire or a pressure plate, or it might be described as an action that causes the trap to go off, like turning a door knob or opening a chest. That includes magically triggered traps that will go off when a specific area is entered or an object is touched.

The effect describes what happens when the trap is triggered. It describes it in terms of what happens in the world and in terms of game mechanics. For example, a spear trap might cause spears to shoot up out of small holes in the floor covering a 10-foot square area around the treasure chest. Those spears might make a melee attack roll against each creature in the area with a specific attack bonus and deal a specific amount of piercing damage on a miss.

It’s important to understand that the trap is more than just a name and some game mechanics. The trigger and the effect are described clearly. And that information is used to determine what sensory information might be available about the trap, such as the holes in the floor and the fact that the chest is bolted to the floor. That information also allows the GM to adjudicate creative ways of dealing with the trap. It is specifically noted on DMG 121 that the players’ are encouraged to take actions to mitigate or foil the trap based on whatever information they have and whatever guesses they make.

Each trap includes mechanical information about how the traps might be detected and disarmed. And here is where I will admit the DMG gets a little “f$&% if I know” about when Investigation checks are required and when Perception checks should be used. But the basic format for each trap is the same. The trigger is described, the effect is described, the ways it might be detected are described, and the obvious ways it might be circumvented are described.

Why Traps Suck in 5E

So, what’s wrong with the…

Okay, before I launch into explaining why 5E’s rules for traps suck, I need you to note that I am not talking about the why the IDEA of a trap sucks. I know some GMs HATE traps in games. That’s fine. Those GMs are just bad and they should feel bad. Because, CONCEPTUALLY, there is nothing wrong with traps. It’s the specific executions of traps in various games and adventures that suck. And part of those specific executions come from the self-same GMs who HATE traps. Yeah, a lot of the people who hate traps inadvertently make them hateful by using them badly and then blame all traps ever. Someday, I will talk about how to use traps in adventure design. But what I’m talking about here is the pure, mechanical way in which encounters with traps are resolved in D&D? I don’t need any of those “this whole article sucks because traps suck in all games ever blargle wargle garble!!!!1!!1!” comments, thanks.

So, what’s wrong with the mechanical execution of traps in D&D 5E? To be honest? Not as much as you think. I mean, it’s garbled as f$&%, but that’s the problem with D&D 5E in general. It’s a good game, presented very badly. There isn’t much consistency, but the basic ideas are good. That’s a damned good framework for traps here.

D&D is being smart in that it is trying to get away from the idea that traps are for the rogue. Most GMs think there’s only ever a reason to put traps in the game if the party has a rogue who can disarm traps. But that’s a f$&%ing stupid viewpoint. That’s like thinking you should only put kobolds in an adventure if there’s a wizard in the party who can put them all to sleep. Rogues are just the easiest way of dealing with traps. They aren’t – and shouldn’t be – the only way. They are the sleep spells of traps-dealing-withery.

And that brings us to something else. A lot of GMs – strangely, many of the same ones who think traps are for the rogue – think traps are only good when they go off. They think that any trap the party detects and disarms or avoids is a waste of time. If it didn’t hurt the party, the party didn’t overcome a challenge. And that’s also a stupid viewpoint. That’s like thinking that if the party managed to get through a combat encounter unhurt, they don’t deserve any experience points because they weren’t really challenged.

Amusingly – if you find abject stupidity funny, anyway – amusing enough, when you combine these two attitudes, you will generally conclude that traps suck. These two ideas are, in fact, half the reason people think traps suck. Think about it. If you think traps are only there for rogues to disarm and traps are only good when they are undetected and undisarmed, there’s really no good way to use traps, is there?

Here’s the f$&%ing truth: a trap that goes undetected until it goes off and hurts someone is the least interesting type of trap there is. There’s nothing exciting or engaging there. It doesn’t require any choices. It doesn’t reward or punish any choices. It’s just a kick in the d$&%.

A trap only becomes interesting when the party has a chance to deal with it. And I don’t mean deal with it by rolling a saving throw to take half damage from a kick in the d$&%. A trap is interesting when the party knows there is a trap in the way and has to deal with that. Do they avoid it and risk stumbling over it later? Do they sabotage it? Do they just leave the treasure chest alone? Do they set off the trap and take the kick in the d$&% in return for the sweet, sweet treasure? And can they do any of that?

But traps aren’t just interesting because of the choices and challenges they create. Traps also provide a way of rewarding players for their skill and ability choices. When the elf with Keen Senses and proficiency with the Perception skill spots the tripwire just before the fighter blunders into it, that player feels good about choosing to play an elf and selecting Perception as one of their limited proficiency choices. They get a warm fuzzy.

Despite being a confused mess, the D&D trap system potentially makes traps interesting and fun in both of those ways by creating several levels of possible interaction with a trap. If the party detects the trap’s trigger or its mechanisms, they can investigate and gain further information. With that information, they can attempt to sabotage the trap. If they succeed, the trap is eliminated and they win. Three die rolls, each one rewarding a different combination of ability and proficiency choices, have the potential to make three different players feel the warm fuzzies. But with each die roll, the D&D trap system is doing something very interesting. It’s shifting the potential intrinsic rewards in the scene. What do I mean?

Suppose the party detects the mechanisms via Perception, but fails to interpret the information via Investigation. Now, they have partial information. They know something about the trigger or the mechanism or both. And now they have the opportunity to overcome the trap via clever means or to make the hard choice to spring the trap or avoid it. If they succeed now, instead of the warm fuzzy that comes with having the right skills and abilities for the job, they have the warm fuzzy of being clever and overcoming an obstacle. Hell, even if they succeed at the Investigation roll, they might still face a tough choice if they don’t have the means to disarm the trap. They might even face a tough choice if they do have the means. After all, if that rogue fails his attempt to sabotage the trap, he’s probably going to take that kick in the d$&% right in the face. Rogues are not terribly durable. I know, I’ve killed a lot of them. And after three or four kicks in the d$%&, they aren’t generally happy to take a fifth.

Once the party knows a trap is there, they have a chance for either their skill choices or their cleverness to pay off. And being a rogue is not a prerequisite. Everyone can make Perception and Investigation checks. And D&D is smart about that too. The Perception DCs for detecting most of the specific traps in the book aren’t aggressively high. And using both Passive Perception and active search rules increase the odds that a smart party will see a trap coming.

So, what DOES suck about the D&D system? Well, there’s a few things. A few things apart from the focus on specific trap rules instead of a general form and the general garbled and contradictory stuff about when to use Perception and when to use Investigation.

First, searching in D&D doesn’t cost anything. Not just for traps. Searching doesn’t ever cost anything. Unless there is a ticking clock spelled out in a specific adventure, time has no value in D&D. And since searching carries no cost, it’s to the party’s advantage to search everything everywhere all the f$&%ing time. Unless they know that their GM never includes traps or secret doors or hidden treasures in the game, players should search constantly. After all, there might be something hidden anywhere and if the cost of the search is just a quick die and the party can make five attempts at every search, not searching is just stupid.

Every GM has dealt with the search-crazy player. It ain’t fun. You want the players to think about where they are searching. You want them to respond to environmental clues and make logical deductions and only search when they suspect there is something to find. If the players search everywhere, it slows the game right the f$&% down. But it also means that, when the players do find anything, they aren’t being rewarded for their cleverness. They are only finding things because of their persistence and random chance.

What D&D needs is a cost for searching. Some kind of risk or cost associated with taking too much time. Maybe some sort of system for tracking time and building tension based on the amount of time being wasted. But lacking that, D&D needs some way to make the search costly or risky or painful so there’s a reason to NOT search.

D&D also needs a way to make traps interesting when they do go unnoticed and when they get sprung. Some kind of rule wherein a player could react based on limited information to something that was about to happen. Suppose, for example, the players could hear the click of a trap’s pressure plate and then have to declare an action like “jump backward” or “raise my shield in front of me” or “dive to the ground.”

My so-called “CLICK!” rule would actually play well the with the layers of sensory information and interpretation that D&D 5E almost manages to make a part of the game. The rogue who fails his check to sabotage the trap can decide to “roll away from the scything blades” because he’s already analyzed the trap. The party that saw the holes from which the arrows will fire can dive to the ground when the trap goes off while they were blundering around looking for the trigger and hopefully allow some of the arrows to sail over their head. Thus, the information the players did manage to gather or guess can mitigate some of the effects of the trap even when d$&% kicks start getting doled out.

And speaking of those layers of sensory information, it would actually be helpful to have a couple of layers of sensory information to help guide the party toward investigating further. First of all, different aspects of a trap might require different Perception check DCs to discover. For example, the slot from which the scything blade will swing might be fairly obvious even under the layers of cobwebs (DC 15), but the small and expertly hidden pressure switch in the floor might not be so obvious (DC 20). Moreover, there could be a layer of sensory information that merely encourages the party to search the area which would work well with Passive Perception. A Passive Perception score of 10 might reveal only that the “wall seems odd here, but you can’t put your finger on why.” That might encourage an active search that would turn up the slot for the scything blade or even the pressure plate.

How To Unsuck Traps

D&D has laid a foundation for how traps should work. It’s a wobbly foundation, sure. Not the greatest. But it’s strong enough that it’s worth shoring up instead of burying and starting again. And based on what I’ve already said above about what D&D is doing right and wrong, there’s already a pretty good conceptual picture of how traps should work. So, let’s just parse that picture down to its barest elements.

GMs and game designers must have a clear understanding of what triggers a trap and what happens when the trap is triggered. That understanding allows for one or more layers of sensory information that can be discovered about the trigger or the trap’s effect or both. While it is possible that either a trap’s trigger or its effect might be beyond notice, one or the other must provide some clue. A trap that is completely undetectable sucks. They must also know the basic methods by which a trap might be sabotaged. And the GM must be willing to adjudicate other actions the players might take to mitigate the trap.

When the party approaches a trap, the GM should determine, based on Passive Perception, what sensory details the party notices outright. If they don’t notice any details, the GM might at least give them a clue that something is off and warrants further scrutiny depending on Passive Perception.

Should the party choose to specifically search an object or area that contains a trap, the GM should determine, based on Perception checks, what sensory details the party notices. The choice to search must involve some kind of risk, cost, or trade-off.

Once the party has uncovered the sensory details that indicate there is a trap, they can choose whether further investigation is warranted. If the party chooses to accept a further risk, cost, or trade-off, they can spend some time examining the mechanism and determine information about how the trap might work and how it might be disarmed. This is determined by an Investigation check.

The party might decide to sabotage to trap, assuming someone in the party is capable of using the right tools. They might do so whether or not they have made a successful Investigation check to understand the trap. But, if they haven’t made such a check, the GM may ask them some specific questions about how they are doing it and may assess penalty for disarming the trap blindly. Alternatively, disarming a trap blindly might carry no penalty – assuming the party guesses at a viable method – but disarming it after a successful Investigation might carry a bonus. In addition to disarming the trap with thieves’ tools, the party might attempt other methods to disarm or thwart or bypass or mitigate the trap with jury-rigged or MacGyvered solutions, which the GM will have to adjudicate normally.

If the trap goes off, each member of the party should be asked how they respond to whatever cue the trap might provide. The party might hear the click of the trigger mechanism or see the shimmer of the magical detection spell. If they don’t know what the trap does, they will have to guess at how to react in that split second. Their reactions should be used to modify attack rolls, saving throws, or other mechanics appropriately, even changing them into automatic successes or failures depending on the specifics.

An entire scene with a trap should play out in five to ten minutes. And when combined with logical placements, foreshadowing, and good adventure design, traps should become a lot more interesting, engaging, and fun. It’s definitely a lot better than the old days of “roll a search roll, roll to disarm, roll a saving throw.” Well, that may be overselling it. After all, in the really old days when rogues sucked at disarming traps, there was a lot more jury-rigging and MacGyvering and a lot less clattering of dice. Granted, there were also a lot more kicks in the d$&%. So maybe this is a happy medium.