The party has finally dispatched the evil priest and scattered his cult, and now have the run of his dark sanctum. It may be that he has stashed treasures in the—
“Perception check to search the room!” declares the rogue, throwing the die.
“Hang on”, says the DM, “you—”
“Ugh”, the rogue groans, “it’s a 2. Can I use my passive Perception instead?”
“I’m going to try Investigating instead” shouts the wizard.
“But you’re trying to perceive your surroundings”, interjects the fighter, “you should roll Perception”.
“No”, says the wizard, “I’m looking at something specific, so it’s Investigation!” The die flies into the air as the DM sinks his head into his hands, defeated.
Skill checks are an important part of the game. They provide a framework to test the talent and training of a character in an endeavour that has a chance of failure. More so than any others, the Perception and Investigation skills are often the source of significant confusion. This article helps resolve that confusion and offers some important advice on running skill checks in your game.
There are a few important clarifications to make about skill checks before we begin.
The first point is that players should never be declaring that they are rolling a skill check. It’s not their prerogative and it often results in scenes like the one that played out above, where the DM has to fight for control of the table. A player’s role is to describe what actions their character is taking as clearly as possible, allowing the DM to determine what happens. As an adventurer’s life is rarely dull and they often find themselves in high-pressure situations or encountering strange sights, DMs will frequently call for skill checks to measure how well they perform.
For example, while it’s an easy thing to find lore in a library, the weaknesses of an ice demon may be a challenge to recall in the midst of battle. Likewise, an accomplished acrobat can probably perform a backflip with ease on even terrain with only a few moments of preparation, but to try to wall-flip over a bunch of debris in a full-on melee might require a bit of luck. An Intelligence (Arcana) and a Dexterity (Acrobatics) check would resolve these situations, if the DM feels it necessary.
The second point is that ‘skill checks’ aren’t actually skill checks. Rather, they’re ability checks to which you can add your proficiency bonus if you are trained in the appropriate skill. Both ability and skill are at the discretion of the DM. For example, if the barbarian decides to bend a metal rod in front of a captive in order to frighten them, the DM might call for a Strength (Intimidation) check. Likewise, trying to swim a long distance might prompt the DM to ask for a Constitution (Athletics) check.
With these points made, we can move on to the main purpose of the article.
Perception vs. Investigation
These two skills are often confused or, worse, treated as Intelligence- and Wisdom-based counterparts of the same activity. Given what we covered earlier about checks being based on abilities, we can see that this idea is particularly likely to cause problems—and it does.
The difference between perception and investigation is the difference between using your senses and using your faculties. The examples provided on PH 178 are especially helpful in determining which skill applies based on what the players describe their characters doing. Most questions about the rules can be readily answered by referring to the books, but assuming that you’re reading this because you’re still unclear, we will endeavour to elaborate.
“I never guess. It is a shocking habit—destructive to the logical faculty. What seems strange to you is only so because you do not follow my train of thought or observe the small facts upon which large inferences may depend.”
— Sherlock Holmes in The Sign of Four
This skill really doesn’t get the attention that it deserves, and that’s why we’re covering it first (and with somewhat greater detail). Many DMs use Perception when they should use Investigation, usually because they’re accustomed to asking for said checks in the context of measuring awareness to threats, and therefore it seems reasonable that the skill might apply to noticing finer details in their surroundings.
To understand when Investigation is an appropriate proficiency to apply, it may be helpful to consider an exemplar of the investigative arts: Sherlock Holmes. This fictional detective is shown on numerous occasions walking through a crime scene, observing countless minor details that others dismissed, and using that information to make deceptively straightforward deductions to general astonishment.
For example, the victim of a murder was left handed. How did he know? In the victim’s home, the ink pot on the left side of the writing space, their table knife with butter on the right side of the blade, their mug on the desk sitting with the handle to the left, and other clues all spoke to it. Without ever touching anything, Holmes uses Investigation to deduce details others overlooked. Though, of course, he can still get down and lift the rug, run fingers behind shelves, throw open drawers and rifle through their contents, et cetera, and still rely on Investigation—it’s a difference in method, not practice.
Adding to the confusion about this skill is that the official adventures also seem to forget that Investigation exists and substitutes Perception instead. For instance, in the starter adventure, Lost Mine of Phandelver, there are many instances (finding a waterproof satchel at the bottom of a well, finding an old chest in a partially collapsed cottage, finding a small wooden case in the ruins of an herbalist’s shop, and more) that should rightly be Investigation checks, but the adventure calls for Perception. And as many other adventures followed the precedents Phandelver set, this issue has continued to compound.
“‘What is the matter, Strider?’ Merry called up. ‘What are you looking for? Did you miss the East Wind?’
‘No indeed,’ he answered. ‘But I miss something. I have been in the country of Hollin in many seasons. No folk dwell here now, but many other creatures live here at all times, especially birds. Yet now all things but you are silent.’
— J.R.R. Tolkien, The Lord of the Rings
Perception is the most commonly used skill in Fifth Edition. While travelling through the wilderness, stalking through a dungeon, or otherwise going about your life, Perception measures your awareness of your surroundings. It helps see candle light under a door, hear the footsteps of an invisible enemy, smell the rot of an approaching zombie, feel the subtle temperature drop as you pass deeper underground, and more. If a check relies on natural senses, you’re probably safe to assume that your proficiency in Perception applies.
We just finished talking about how the official adventures often call for Perception checks where Investigation is more appropriate, but there are many examples to be found where they get this right. Phandelver gets it right at least half the time, and so there are many excellent examples of Perception to be found. Listening through doors in the enemy hideouts, catching a whiff of strange odours, searching for hidden enemies, and keeping a lookout while travelling are all sensible and effective uses of the skill. These are cases of using your general awareness to notice something amiss.
Is there occasionally overlap with Investigation? Certainly, but such cases are really much less common than one might think. We encourage you to bear that in mind as you run or design dungeons, as it makes the game much less focused around one single skill—one that not every class gets proficiency with.
It is also worth including a helpful note here about the game’s most frequently used passive score: your passive Perception. Passive scores are often misunderstood. For instance, a common question we see is “Can I roll lower than my passive Perception?” This is troublesome for several reasons, mostly because it is another example of players trying to use game mechanics—skills in particular—without being asked.
To clarify, passive scores are not a player tool, they are a DM tool. Passive Perception is intended for use in resolving hidden threats as an alternative to tipping the players that something might be amiss by calling for Wisdom (Perception) checks. As an accurate measure of someone’s average perspicacity, passive Perception is best used in practice to approximate a character’s general attentiveness, rather than their focused interest. If someone wants to pay attention for something specific, it is more appropriate to have them roll a Wisdom (Perception) check. And no, their passive score doesn’t factor in as a benchmark.
Putting It All Together
Investigation and Perception have similar objectives: to learn more about the world around them. The difference lies in the way that information is obtained. Investigation relies on observation and deduction and Perception relies on awareness and natural senses. This simple rule of thumb can help eliminate many disputes before they can begin.
Yet, even with this clarification, it’s silly to think that there will never be confusion about what skill(s) may apply to what situation. This is why the DM is singularly empowered to call for checks and to decide which ability and skill is relevant to the task at hand. Reminding your players of this fact, along with their responsibility to clearly explain what their character does, may go a long way to preventing such confusion from getting out of hand.
Have you had a notable experience with skills and ability checks? We’d love to hear from you in the comments below!
10 thoughts on “D&D Tips: Perception vs. Investigation”
To elaborate further… If your perception shows that a statue has been scraped across the floor and it cannot be moved, then an investigation check on the items and walls of the room could be used to see if there are signs of a sconce being turned, or a place on the wall that has the oil residue of someone who touched or pushed something there many times. ….Unless it is obvious, or a little more obvious, then it is a perception check. If it is anything that requires an amount of intellegence to figure out (which most characters don’t put stat points in (Int), then nobody can figure out anything unless they just go around the room twisting and pulling everything, which someone would have to suggest doing to see if anything happens (if they think to do that).
Intellect skills are used only rarely in gameplay, mostly in History and Arcana checks (which doesn’t amount to a whole lot of checks for anyone (unless it is module specific). The investigation skill can give characters a valid reason to not dump Intelligence as a worthless stat. It allows them the ability to figure out how things work, including intrigues, traps, business dealings, research, how to figure out what the local monsters and society are going through, how to craft things, how to find things, anything that you can come up with to not just have it a perception check. That will make Investigation an important skill!
One difference of the perception and investigation skill is in traps . The perception skill is used in noticing that something is out of place or odd in the way the floor tiles are situated, ceiling structure is off , holes in the walls, etc., but the investigation skill could tell that stepping on the tile on the floor sets off the trap to shoot darts out the holes on the wall, drop the ceiling, or potentially unleash a fireball to roast everyone (if the tell tell signs of previous damage are clues, or if detect magic detects something is magical, but not sure what). Investigation figures out how a trap works so that it can be disarmed without killing the party.
I am a new DM and this is very helpful. I am playing with a small group, my Wife, BFF and his wife. He got pissed when I told him his investigation in the Throne Room of Gnomengarde in Icespire Peak adventure may take awhile. He always wants to say I’m rolling for this or rolling for that. He has played alot more than me and I actually rely on him for some judgements when I don’t know the rules. How can I take over as DM and put him in check even though he may know the rules a bit better. Also he is going to his monster manual and questioning how I set up the game?
Thank you for your question.
My suggestion is that you have a chat with your friend acknowledging that he has more experience with certain aspects of the game, but that doesn’t mean that his judgment trumps yours as the DM, especially when it comes to adjudicating those parts of the game that are expressly at the DM’s discretion.
For example, if you say it takes 20 minutes to do a thorough investigation of a room based on the result of his check, then that’s how long it takes. If he has a problem with that, ask him to ‘do an Investigation check’ of your game room looking for his character miniature (or some other object you’ve hidden). When he realizes that it’s not so easy as just rolling a die—that the roll represents a whole series of actions as the character checks everywhere they can think of—then this problem shouldn’t happen again.
You could also ask him to ‘do a Perception check’ and then call him out when he does something other than listen, smell, and/or look around the room from where he is standing. By giving him a real life example of the difference between the two, you can probably avoid more confusion.
Passive Perception *IS* the floor of any Perception check, because if PP was enough to detect X, the DM should have already informed that player of X.
The designers said so in a podcast you can easily find online.
Thank you so much! I have been running 5e since it came out and literally never had my players use this skill because I mistakenly thought it was basically “gather information” from 3.5 and I never liked that skill to begin with. It was just recently that I realized it was a sort of sister skill to Perception but I didn’t really understand it well enough to use it until this article.
My personal take on using the skill as a benchmark pretty much comes down to the fact that I have a player with a passive perception of 19, which means I would either have to have all of my perception checks be minimum 20 or not matter at all.
Hi! I’ve been struggling with this topic myself for quite some time, but I feel like you are off in a few things, and I would love to start a conversation about that.
On the topic of the Phandelver starter adventure, I feel like some of the things you mention as being wrongly presented as perception skill checks, even though I agree with some of them, don’t you think that the ones that would be possible to perceive with a naked eye like the chest in the cottage, should fall in perception?
It is possible to see the red hankerchief that is almost totally covered by the big brown coat on the rack behind the door just by looking around, if you are perceptive enough. Most people would not see it, but a high perception should be able to see it.
In any case, what I really would love to get into, is the part where you state that the passive perception doesn’t factor in as a benchmark. Apart from the fact that the designers already told that it should be taken into account as the skill floor, why do you think it shouldn’t factor as benchmark? I mean, the passive perception is working all the time. Why shouldn’t be working the moment you roll the dice? The second your active attempt to perceive something is done, the passive kicks in again.
I think it diminishes the value of someone being perceptive if they can’t be as perceptive trying as they are when not trying at all, and encourages not rolling, since 50% of the time you really are being less perceptive than you usually are without even trying.
The DM in a game I am playing is also ruling passive perception as a benchmark just as you are suggesting. However, I disagree.
It is so very well explained in this article:
‘Passive Perception is intended for use in resolving hidden threats as an alternative to tipping the players that something might be amiss by calling for Wisdom (Perception) checks. ‘
So, passive perception is not your minimal perception; it is an average value (10) with your bonus proficiency, and its sole purpose is to not roll every time a hidden danger or secret door is nearby, so that you don’t alert your players to it. It is not a perfect representative of your perception but it is a good mechanic to streamline the gameplay.
That being said, I really like how you approached this article with the desire to start a communication and it is a shame that the author didn’t reply or that it doesn’t have more comments because it is an excellent article regarding Perception vs. Investigation.
Thanks for your comment!
It’s strange… I thought I replied to this comment a long time ago. I suspect I’m confused with a similar comment on another article, as this debate has come up a few times.
There are a few reasons why I disagree with allowing the passive to function as a benchmark.
(1) It invalidates the purpose of the rogue class’ Reliable Talent feature (can’t roll below 10 on skills in which the character is proficient—an 11th-level feature!).
(2) Every skill in the game has a passive score, not just Perception. Making the passive score a benchmark for Wisdom (Perception) makes as much sense as making the passive score a benchmark for Strength (Athletics) or Dexterity (Stealth). If this logic is followed through, half the results on a d20 become meaningless because you just “did better because”.
(3) Passive checks are a DM tool, not a player tool. The DM uses them to approximate a character’s performance when there is cause to not have that character roll a check. This could be because the DM doesn’t want the player to know there’s a goblin sneaking up behind their character or that the NPC is being deceitful with them, or because they’re performing a repetitive task that would require the same roll over and over again.
At the end of the day, when a character is actively doing something, a passive score shouldn’t come into play. We have dice to be rolled, and those rolls need to matter. Don’t like the result? Too bad. Alea iacta est.
Those are my thoughts on the matter. It may be that at your table these problems don’t come up, and you prefer to minimize the number of rolls people have to make. And that’s fine, it’s just not how I run the game nor how I think it was intended to be run (for whatever that’s worth).
Regarding your specific Perception vs. Investigation question, finding a handkerchief partly concealed beneath a coat could potentially be either skill. It depends greatly on how the player frames what their character is doing, and the DM may have to ask them to elaborate on this. “I’m going to look around” is far too vague most of the time; do you mean that you’re standing in the middle of the room and just staring in whatever direction takes your fancy and noting the placement of things, or do you mean that you’re going around each area of the room and pulling back furniture, bedsheets, coats, etc? The former is Perception (like it would be to listen or smell the vicinity), the latter is Investigation.
To put it in other words: perceiving your environment is largely a passive activity that relies on your senses while investigating your environment involves careful observation and scrutiny. Perception might let you feel an unexpected draft, but Investigation will find the mechanism to open secret door that is causing it. Why? Because otherwise what’s the point in even having an Investigation skill?
That’s how I look at the two skills.
I would like to put forward a counter-explanation of passive perception (and investigation, which strangely you do not even seem to consider).
First of all, while they are a DM tool, if the DM is ignoring them out of ignorance, it is not unreasonable for a player to at least question that. Ideally this should be discussed between them between sessions but nevertheless, it being a DM tool does not mean the DM is using such tools as intended.
More generally, though, I put it to you that the better description of the difference is that passives detect ongoing situations. If someone is hiding somewhere in line of sight then they are hiding exactly the same over time. Rather than going to rounds and rolling round to round perception checks, passive perception stats are used.
On the other hand, if it is a question of trying to hear a door open, or a single line of dialogue, or see a brief flash of colour or some other one-of event, then it is a regular perception check.
Passive Investigation is also a thing. Most of Sherlock Holmes’ examples are passive perception. As you described, he walks into a room and notices relevant things. Everything in that room description you gave from Sign of the Four is just sitting there. It was there before he came in, there while Holmes walked around the room and still there when he left. All that time he was able to observe it, his passive investigation applied.
If, on the other hand, it was a one shot occurance (or series thereof), a regular investigation roll would apply. Recognizing that a gesture between two people was a subtle communication, for example, just from that one snapshot view.
There is even an argument for both being needed in some cases. In the gesture example, a perception roll to have seen it at all in a crowded room and an investigation roll to recognize its significance. Your draft example there is arguably another example of such a situation, however in that case passives should also apply, since it is unlikely such a draft is just a one shot and the door is always there either way…