D&D 5E Passive Investigation?

[iserith]

I've been tempted recently, with the megadungeon the group is currently working through, to remove passives entirely, or to change how passives work.

In the former idea, the PCs don't notice anything if they're not going, "I'm going to check that!" Tough cookies if they should have, and trigger a trap.

In the latter, I don't know whether I'd make it just base modifier is your new passive, or something different entirely.

Technically, they are saying "I'm going to check that..." if you are using their passive score to resolve any uncertainty as to whether their checking turns anything up. They're just saying "I'm going to check that..." over and over and over again.

The trick is, to make it a meaningful choice, you need to make marching order and travel pace important plus provide some good trade-offs for not keeping watch for danger. You'll also want to telegraph hidden dangers to make sure it's fair.

 

[quandaratic]

That's not the case because by definition a passive check resolves a different kind of activity than an ability check does because the former is for tasks performed repeatedly.

No, a passive check resolves the exact same activity, because repeating a task doesn't change the essential nature of the task. The Players Handbook example would be a simple ability check, but the DM just decides the result is a single score instead of the many results of many checks. It doesn't mean that the character searched for secret doors any differently, just many times.

In the context of the podcast, they were talking about hiding in combat and how that related to a Search action.

In that podcast, they specifically said that they were talking about Stealth in and out of combat. Crawford also provided non-combat examples, of a the Dugrand ball, and of just watching minstrels perform.

there is a "floor" because the DC for hiding is set by the opposing passive Perception score. If the monster can't beat that, they aren't hidden anyway, so that's effectively the "floor."

That's not how they proposed passive perception to provide a minimum possible result. What they said was, that if a character who is actively making a perception check rolls low, they would use their passive perception score instead of the result of the die roll.
Here is what Crawford said, verbatim: "It really represents the floor of your perception. ...and so, if you make an active perception check, and you get a number that's lower than your passive perception, all that means is that you did a lousy job of this particular active search, but your passive perception is still active; you're still going to notice something that blips onto your passive perception radar. Really, when you make that roll, you're rolling to see 'can I get a higher number?' If you fail to, well, again, your passive perception score is still active. It is effectively creating the minimum."
The rule, as he wrote it, is definitely, that a player cannot get a perception result lower than their passive perception score.

 

[quandaratic]

The travel activity rules show that Passive Perception is not quite "always on".

It does definitely say that characters doing other things don't get to use their passive perception, while traveling.
Crawford also suggested, in the podcast, that it makes total sense that stealth might automatically succeed against passive perception, for a character whose attention is focused on a particular thing. ...and it does make sense. It just might depend on that thing.
I'd suggest that the activities while traveling section mentions it as an override to the general rule, because specific beats general.

 

[iserith]

No, a passive check resolves the exact same activity, because repeating a task doesn't change the essential nature of the task. The Players Handbook example would be a simple ability check, but the DM just decides the result is a single score instead of the many results of many checks. It doesn't mean that the character searched for secret doors any differently, just many times.

Doing a thing once and doing a thing many times are two different activities and they are resolved different in the rules.

In that podcast, they specifically said that they were talking about Stealth in and out of combat. Crawford also provided non-combat examples, of a the Dugrand ball, and of just watching minstrels perform.

That's not how they proposed passive perception to provide a minimum possible result. What they said was, that if a character who is actively making a perception check rolls low, they would use their passive perception score instead of the result of the die roll.
Here is what Crawford said, verbatim: "It really represents the floor of your perception. ...and so, if you make an active perception check, and you get a number that's lower than your passive perception, all that means is that you did a lousy job of this particular active search, but your passive perception is still active; you're still going to notice something that blips onto your passive perception radar. Really, when you make that roll, you're rolling to see 'can I get a higher number?' If you fail to, well, again, your passive perception score is still active. It is effectively creating the minimum."
The rule, as he wrote it, is definitely, that a player cannot get a perception result lower than their passive perception score.

I'm not going to listen to it again to verify the quote so I'll take your word for it that it's accurate. That said:

Characters don't "actively make a Perception check."

There is no "active perception check."

And the only situation in which there's a minimum, by the very rules they're very badly talking about, is in combat.

They may rule otherwise in their games, but the rules don't back this up as far as I can tell.

 

[quandaratic]

Characters don't "actively make a Perception check."

There is no "active perception check."

Just so I'm sure, are you saying that a player will never roll a die, and add their Perception skill modifier, to check what their character observes about their surroundings?

And the only situation in which there's a minimum, by the very rules they're very badly talking about, is in combat.

They may rule otherwise in their games, but the rules don't back this up as far as I can tell.

Also, just so I'm sure, are you saying that the rules don't work the way that is described by the lead designer of the game's rules?

 

[iserith]

Just so I'm sure, are you saying that a player will never roll a die, and add their Perception skill modifier, to check what their character observes about their surroundings?

No, I'm not saying that. Characters don't make checks. Players do, when the DM asks for one, which is when the DM determines that the player's stated approach to a goal for the character has an uncertain outcome and a meaningful consequence of failure. Therefore "characters don't 'actively make a Perception check.'"

Also, just so I'm sure, are you saying that the rules don't work the way that is described by the lead designer of the game's rules?

Given that the lead designer is referring to things that aren't actually in the rules, such as "active perception checks," maybe so. To argue that he's right because he's the designer is, I believe, a logical fallacy. What the rules say and how someone uses them in their personal games can be different even among the designers of the game.

If a creature is trying to hide, a character's passive Perception score (+1) is the DC to meet or exceed. If the character is not keeping watch for danger or is not in the fictional position to notice a hidden creature, the passive Perception score does not apply because there is no uncertainty - if the creature meetings the requirements for hiding, it is hidden, no check needed. To the extent the passive score is a "floor" for a subsequent ability check is when the creature is already hidden because the monster met or exceed the DC to hide. The passive check already indicated the the character keeping watch for danger while adventuring failed to notice the monster.

Those are what the rules say. If Crawford plays it differently for some reason, that's his right, just like any other DM.

 

[quandaratic]

Given that the lead designer is referring to things that aren't actually in the rules, such as "active perception checks," maybe so.

I think you're taking the phrasing too literally, but I agree that there aren't any references to this concept, that the passive perception score should be used in place of a low result on a perception check. If it's supposed to be the official version, it's either a big oversight, or a very confusing way of supporting DM's choice.
I don't know if I would use this rule, personally.

 

[iserith]

I think you're taking the phrasing too literally, but I agree that there aren't any references to this concept, that the passive perception score should be used in place of a low result on a perception check. If it's supposed to be the official version, it's either a big oversight, or a very confusing way of supporting DM's choice.
I don't know if I would use this rule, personally.

I think it's irresponsible of the designers to use terms that aren't in the rules to discuss the rules. It just creates confusion, especially with something like passive checks since passive does not refer to the inaction of the character, but rather the fact that there's no roll.

I believe Crawford is right that you can think of passive Perception as the "floor," but only in certain circumstances. It therefore cannot be applied across the board and, in my view, doesn't even need to be discussed since it only causes more confusion. You don't need to think of passive Perception as a "floor" to make rulings in accordance with the rules.

I would just put it out of your mind.

 

[Tony Vargas]

Given that the lead designer is referring to things that aren't actually in the rules, such as "active perception checks," maybe so.

Remember, with 5e they decided to lean more on natural language than jargon, so the onus is more than ever on us to read for comprehension, rather than on then to code unambiguously.

Is it hard to understand that 'active perception' is being used to contrast making a check to which perception proficiency will apply vs resolution involving passive perception? No. So it's a perfectly reasonable way to put it.

Personally, though my thoughts on the matter have nothing to do with who said what how, but more with the probabilities involved.

A passive check - comparing a passive score to a static DC - for instance, is nonsense. Not because it parses as nonsense, but because the DM sets difficulties, so it's just the DM ruling success or failure rather than uncertainty. There's just a superfluous step of setting a DC that will mean success or failure, then 'checking' it.

On the other extreme I don't care for contested checks at all, they get 'too swingy' - in the sense that gets used around here.

So, that leaves checks. D20 + bonuses vs a DC. Rule success or failure or call for a check. There's one place a passive score fits in that mechanism: as a DC.

So, if a slithering tracker sneaks up on a PC, it's stealth check vs a DC of his passive perception. If a spy leaves a purloined letter at a dead drop the PCs have access to, he makes his check vs their passive investigation, perhaps?

 

[iserith]

Remember, with 5e they decided to lean more on natural language than jargon, so the onus is more than ever on us to read for comprehension, rather than on then to code unambiguously.

Is it hard to understand that 'active perception' is being used to contrast making a check to which perception proficiency will apply vs resolution involving passive perception? No. So it's a perfectly reasonable way to put it.

It's less about adhering to jargon than not confusing the listeners many of whom are already confused about what "passive" actually means in reference to a passive check. I'm perfectly capable of knowing what he means. But his use of "active" in this context muddies the water.

Personally, though my thoughts on the matter have nothing to do with who said what how, but more with the probabilities involved.

A passive check - comparing a passive score to a static DC - for instance, is nonsense. Not because it parses as nonsense, but because the DM sets difficulties, so it's just the DM ruling success or failure rather than uncertainty. There's just a superfluous step of setting a DC that will mean success or failure, then 'checking' it.

We've had this discussion before. I view it now as I did then: A passive check resolves uncertainty the same as an ability check. A task (approach to a goal) is determined to be uncertain, a DC is determined, and if the task is being performed repeatedly, a passive check is used to resolve it. If it's not repeated, an ability check is used. The uncertainty determination happens "upstream." I think I also touched on this recently in the thread on Expertise as a way to resolve issues with Expertise causing a call as to uncertainty to be an auto-success. Auto-success, like uncertainty, is determined earlier in the adjudication process.

On the other extreme I don't care for contested checks at all, they get 'too swingy' - in the sense that gets used around here.

So, that leaves checks. D20 + bonuses vs a DC. Rule success or failure or call for a check. There's one place a passive score fits in that mechanism: as a DC.

So, if a slithering tracker sneaks up on a PC, it's stealth check vs a DC of his passive perception. If a spy leaves a purloined letter at a dead drop the PCs have access to, he makes his check vs their passive investigation, perhaps?

I would say an example of passive Investigation coming into play might be as an activity while delving, say, a ruin of an ancient empire. The dungeon has pictographs or the like all along its many hallways. Rather than keep watch, navigate, forage, track, draw a map, etc., a character would have the option to study these pictographs while delving to deduce valuable lore of some worth to sages (perhaps worth X gold back in town per sector of the dungeon explored). Due to the esoteric nature of the hieroglyphs, the less than ideal conditions in the dungeon, and places where the runes were defaced by monsters or faded with time, a standard investigation uncertain. (Leaving the door open for other approaches the PCs propose to be more or less certain or difficult.) Therefore, it's a DC 15 passive Intelligence (Investigation) check at a Slow pace and a DC 20 passive Intelligence (Investigation) check at a Normal pace, and an auto-fail at a Fast pace. Further, when traveling at a Slow pace, the chance of running afoul of a wandering monster increases relative to traveling at a Normal pace. As you can see here, that specific task (or tasks, if you want to consider the tasks at a given pace to be distinct) has an uncertain outcome with the result determined downstream in the adjudication process.

Going back to passive Perception, a character engaged in studying the pictographs is not keeping watch which means he or she is automatically surprised by wandering monsters sneaking up on the party and runs afoul of traps if the character is at the front of the party when it runs into them. That is, unless the character is a ranger in favored terrain. The upside is that hopefully the character lives long enough to go back to town and sell this useful information to the sages.