D&D 5E Perception vs. Investigation in UA Traps Revisited - A problem again?!

[ThePolarBear]

Again: Neither do I argue how to use Perception/Investigation, nor do I argue that those checks are not valid in the situations that are stated in the UA Trap rules. I am absolutely fin My point is, that you can't investigate somehing that you haven't noticed.

Absolutely. The opposite is also possible however: unless you lift a carpet you can't see what's beneath it. And the something you find might very well be blatant the moment you actually lift the carpet, requiring no roll whatsoever even if its "an act of perception".

You wirte "Perception has already passed, possibly because the difficulty to notice them was so trivial". Maybe we have differences of opinion cocerning "what is trivial to perceive". In my opinion "faint burn marks" are not easy to spot (in contrast to BIG FAT BURN MARKS). Furthermore I think that "scuff marks and wear pattern" are also not trivial and therefore no auto success - especially, if there are other conditions like if the characters are in a hurry or exhausted (disadvantage on ability checks).

Possibly means possibly. It's just a possibility. It might have required a perception roll. Still missing the point: The example brought forward is NOT that of a functional trap but how the two different skills are used in regards to traps. Perception to notice something, Investigation to gain informations that are not immediatly apparent. In the example, the knowledge of the marks on the door is a given. How such information has been acquired is not revealed.

In regards to burn marks the fact that are faint does mean something: you do not perceive them - at least not as burn marks. No amounts of looking around will let you distinguish said burn marks from other black spots, until you get down on your knees and start touching, analyzing the runes, passing your fingers on them and on the mosaics. At that point, assuming you have been thorough enough on your investigation, the difference is apparent without a roll.

You are not investigating something you can't see. You do see that the mosaic has black spots, just like it has red, purple, green ones and runes and whatever. You are investigating something you are already looking at, and want to know more about it. You either realize that what you are looking at is not what you expected it to be or you don't.

No matter how good your perception is you are not going to identify water just by sound: You hear a liquid sloshing. That's it.
Even if it looks like water, sounds like water, smells like water, taste like water - it might still be poison.

Again, I do agree on using Investigation to deduce facts/evidence to find a trap. But these rules ALWAYS ask for perception to find "obvious traps". But the moment Investigation comes into play, it seems like Perception doesn't have to be taken into account at all. It's alway either Perception or Investigation. But for some strange reasons you never seem to need both. That is not consistent.

How is that not consistent? If it is always that way, it IS consistent

You never need more than one roll to identify a threat. Why?
My opinion:
a) Rolling is more complex than not rolling, so 2 rolls is more complex than one and takes more time.
b) It increases the chance of failure no matter what: You have to succeed twice to obtain a single advantage. This might lead to group unsatisfaction.
c) It uses "do not roll if not necessary" to skip parts that would be so obvious that rolling would not be required.

Now, obvious traps are obvious because there's something that can be perceived as "obviously" out of place. No need for an investigation check.
Non obvious traps require logic to see them through because the trigger is non obvious. Even if you see it, you won't recognise it. Or prehaps you won't even be able to see it at all because it's just in a non obvious place, where it's just not normal to look at.

Once an investigation is done, you ALREADY know that there's something wrong because the effects are not difficult to perceive once you know what too look for.

And again, this is how the "official" rules are. You do not like it? Do not run as they say. You do not find that consistent? Fix it at your liking. I personally have zero problems with applying rules as is when i feel like it, and changing them if i want to. Zero problems with having impossible tasks being impossible and not even checks, trivial tasks not be checks too, and gating apparent discoveries that should fall under another skill behind something that makes more sense does not infringe my suspension of disbelief.

 

[Caliban]

I'm gonna give the benefit of the doubt, and assume you aren't screwing with me.

In which case, I apologize for coming across as condescending, and seeming to attack you. Neither was remotely what I meant to do.

Sorry for taking it personally. I was having a bad day yesterday and probably shouldn't have been posting at all.

 

[doctorbadwolf]

Sorry for taking it personally. I was having a bad day yesterday and probably shouldn't have been posting at all.

It's all good. I was also in a bad mood

 

[lkwpeter]

In regards to burn marks the fact that are faint does mean something: you do not perceive them - at least not as burn marks. No amounts of looking around will let you distinguish said burn marks from other black spots, until you get down on your knees and start touching, analyzing the runes, passing your fingers on them and on the mosaics. At that point, assuming you have been thorough enough on your investigation, the difference is apparent without a roll.

You are not investigating something you can't see. You do see that the mosaic has black spots, just like it has red, purple, green ones and runes and whatever. You are investigating something you are already looking at, and want to know more about it. You either realize that what you are looking at is not what you expected it to be or you don't.

Actually, we are not far away in most points.

Your example:
1.) You do see that the mosaic has black spots, just like it has red, purple, green ones and runes and whatever. You are investigating something you are already looking at, and want to know more about it.
2.) You either realize that what you are looking at is not what you expected it to be or you don't.

My point of view:
1.) You see a room. You gain plenty of impressions. You see everything that is obvious und therefore described through the DM. You see a mosaik as one part of the room.
2.) What you do NOT automatically recognize are faint black spots on the mosaic. Yes, you automatically see them, if the character pays its attention to it. But if it just walks through the room, there is no way, the character automatically sees differences on the mosaic! A perception check is needed. Afterwards Investigation for deducing the information found.

All in all, I am speaking of that "uncertain outcome" (PHB, p. 174) of ability checks. If a character turns its attention to the "mosaic" or "doorknob" (see examples above), I am fine with your interpretation. But if the character just walks through the room with the mosaic or opens the door without putting much attention to it, the outcome is uncertain. And that means, Passive Perception comes into play. If the character fails the check, there is nothing to deduce.

My intention was, that the UA Trap rules seem to skip the part of a possible uncertain outcome of perception. To raise the stakes: Let's say the character is blind. How would it be able to deduce those facts that it can't even see? The new rules doesn't take such things into cosideration at all. They imply that any Perception check is dispensable, if an Investigation check is made. Maybe they don't intent to. But if you read the whole document and compare situations where a Perception check is needed and those that require an Investigation check, you somehow end up in this conclusion.

Wisdom is, at least in the case of traps, the ability relating to your sensory perception. The role that the Perception skill plays, then, is quite clear; it's whether you spot that hidden trip wire, or that discoloration from a not-quite-perfect concealment, or that blood stain. Intelligence governs your deductive and inductive reasoning. It is your ability to draw inferences and conclusions to what you have already perceived, as well as your ability to perform tasks, for lack of a better term, heuristically (such as a methodical search). This is why "Search", as a skill, used to key off of Intelligence and not Wisdom, and why Investigation, and not Perception, is the most obvious successor to that skill.

Here's how I adjudicate traps:
*If the trap has a visual component, I compare that component's DC vs. the PC's passive perception to see if any of them notice the component.
*How the PC's choose to react to the information tells me whether to call for a Wisdom (Perception) check (e.g, "Do I see anything else?") or an Intelligence (Investigation) check (e.g, "I check the wall next to it; do I find anything?")

Generally speaking, pretty much every trap I design has several visual components (with separate Wisdom (Perception) DCs, so some obvious clues will spotted through Passive Perception, while better concealed components would require a more thorough active check) and most have non-visual components (which would necessarily have to be revealed through an Intelligence (Investigation) check).

That's exactly what I am speaking of. Happy to hear that. Thanks for your comment!

 

[Yaarel]

I get what the rules for the Perception/Investigation split seem to want to do. At the same time, the descriptions seem confusing or confused.

I would rewrite "Perception" as only "what can be perceived through the empirical five senses". Most sensory input is automatic. But some sensory information is faint, subtle, partially obscured, or camouflaged. If a sound is faint or drowned out by other sounds, if a sight might be subtle, if a smell faint, then a Perception check is necessary. A successful check gains a description of the sensory information only. Ever. If something is completely concealed, or a scent is upwind, then a Perception check is useless.

To recognize or figure out what the sensory pattern might mean or imply, always requires an Investigation check. Many attempts to recognize something are automatic (a chair is a chair, and most people would be familiar with it). But if something might be unobvious or strange, then an Investigation check is necessary.

If someone succeeds on a Perception to notice a tripwire. I would never use the word "tripwire" in the description. I would say, you see some kind of string stretched tight near the ground. And wait to see if any players decide to pull at it out of curiosity.

 

[Ristamar]

I would never use the word "tripwire" in the description. I would say, you see some kind of string stretched tight near the ground. And wait to see if any players decide to pull at it out of curiosity.

Unless you're running a group that has little to no experience with D&D (or similar games), isn't that a bit a pedantic?

 

[Yaarel]

Unless you're running a group that has little to no experience with D&D (or similar games), isn't that a bit a pedantic?

Heh, if the DM refuses to "lead" the players, the players tend to learn the hard way.

One DM who I admire would make sure to add an encounter that is impossibly high level, that players must avoid. The first time I encountered it, is when the rest of the players were in palpable terror because they suspected one of the monsters that we saw in the distance might be one of these high level encounters. Mixing up the levels adds to the verisimilitude of the game world.

Somewhat similarly, if the DM wants to make traps a thing within the game world, then seeing what players do if they suspect a trap, is part of the entertainment.

 

[BookBarbarian]

I seriously doubt it.

No ability check is ever required. Whether or not an ability check is called for is entirely up to the DM, based on his or her judgment as to the certainty or uncertainty of the outcome of the player's stated goal and approach for the character given the fictional circumstances at play.

Indeed. The detecting of the presence of a Trap and whether a Wisdom check with Perception proficiency added or an Intelligence Check with Investigation proficiency added will depend entirely on what approach the player is taking to discover the traps, assuming they are taking any approach at all if they are not they will find it by the most fun way of all: Triggering it

Now that isn't to say the OP doesn't have a point. If the writers of the UA Article were attempting to help DMs describe the results of a Perception or Investigation check they could have done better differentiating how one might consistently describe one versus the other.

Fortunately UA articles typically come with feedback surveys.

 

[ThePolarBear]

My point of view:
1.) You see a room. You gain plenty of impressions. You see everything that is obvious und therefore described through the DM. You see a mosaik as one part of the room.
2.) What you do NOT automatically recognize are faint black spots on the mosaic. Yes, you automatically see them, if the character pays its attention to it. But if it just walks through the room, there is no way, the character automatically sees differences on the mosaic! A perception check is needed. Afterwards Investigation for deducing the information found.

That is exactly what i'm saying. No amounts of perception will ever allow you to see the marks, unless the act of perceiving is made at a distance of 5 cm. (exageration, i know.) At that point, only if you are looking at the right place with the right inquisitive mind you are able to understand what those spots actually are. They are dead obvious. It's not about seeing them. It's about understanding what they are.

All in all, I am speaking of that "uncertain outcome" (PHB, p. 174) of ability checks. If a character turns its attention to the "mosaic" or "doorknob" (see examples above), I am fine with your interpretation.

If the character is investigating the mosaic then the attention is clearly there.

But if the character just walks through the room with the mosaic or opens the door without putting much attention to it, the outcome is uncertain. And that means, Passive Perception comes into play. If the character fails the check, there is nothing to deduce.

No, the outcome is certain. He does not notice the marks for what they are. There's no requirement for perception, because perception alone does not help.
No amount of rolling will let you jump to the moon. No amount of perception will let you recognise the marks, unless you happen to be looking for some clue specifically.

My intention was, that the UA Trap rules seem to skip the part of a possible uncertain outcome of perception. To raise the stakes: Let's say the character is blind. How would it be able to deduce those facts that it can't even see? The new rules doesn't take such things into cosideration at all.

That's because the old general rules still apply. If something it's impossible, something it's impossible. It's not uncertain. There's no roll. The fact itself that there is no roll listed indicates that perception is not what it takes to identify what happens in this case - RAI.
A blind person is blind. (i know, i love tautologies. edit: Well, repetitions, more than tautologies.) No matter how hard he tries it's not going to see anything, no matter what he tries to do. It's up to the DM to rule on this cases. The roll is investigation, but requires visual input for at least a part of the informations. This case? For me it might set off the trap, end up touching the ash and understanding what is is, feeling the indentations of the runes, if there's one. Or it might end up touching a part of the mosaic that's clean and not notice anything.

And yes, TECHNICALLY understanding that what is being touched is ash is perception. How difficult is that however? Is it really meaningful (again, another rule for rolling) to have a roll that's probably quite easy and really not more important than the player actually expressing is willfulness to inspect thorougly something?

They imply that any Perception check is dispensable, if an Investigation check is made. Maybe they don't intent to. But if you read the whole document and compare situations where a Perception check is needed and those that require an Investigation check, you somehow end up in this conclusion.

Is a perception check dispensable for following tracks? Yes, that's just survival. You might find the tracks, you might not, but either way you are unable to follow them or learn anything useful if you fail.
Is a perception check dispensable to look for the right tome in a library? Yes, that's most likely an investigation or an arcana check. You do see books, how you search for the book you are looking for is way more important than how visible the book actually is - in most cases at least.

Would you advocate that to grapple you have to make an acrobatics check to see if you do not lose your footing, then an attack roll to see if you actually come into contact with the creature you are trying to grapple, then the athletics check to see if you can actually hold it, then another acrobatics to see again if the struggle does not bring you down? Or even just two of these?
It's the same for traps. For some actually see something is more important than knowing how it works. For others the other way around is the most important. And the roll is just one - in the intentions. (Not that it really needs repeating, we are on the same page here) A Dm is always free to change that for any reason, as long as it's for making the game more confortable for his group.

All that said, if a character walks on the mosaic the trap triggers, so if seeing a mosaic on the ground does not put your team on high alert they are going to perceive the trap from a very advantageous position

If someone succeeds on a Perception to notice a tripwire. I would never use the word "tripwire" in the description. I would say, you see some kind of string stretched tight near the ground. And wait to see if any players decide to pull at it out of curiosity.

Dunno. If i use tripwire i might be committing either an error (i'm letting more informations out than what is actually availlable) or giving out a specific indication that's clear on the intent of what is being seen - a tripwire, a contraption that is based of a triggering mechanism connected to a wire or other form of string that serves to activate something. I might use "string" or "tripwire", depending on how much i think is right for the players to know. I do not usually describe a corridor as something like "an open space lined in worked rocks of non-identified kind that streches in lenght for an unknown distance, that's more or less regular in shape, about 4 arms of width and 8 in height" after all