5E Passive Investigation?

Savage Wombat

Adventurer
I've got a player taking the Observant feat.

One of the lines is: "You have a +5 bonus to your passive Wisdom (Perception) and passive Intelligence (Investigation) scores." Now, passive Perception gets mentioned all over the place, but passive Investigation? Is this just for when the DM has a clue for you, but no one's said they're looking at the crime scene?

I think I'm just having a hard time coming up with examples in my mind. Is there anything in HotDQ or other published materials actually asking for passive INT checks? Has anyone used them in their game?
 
I've got a player taking the Observant feat.

One of the lines is: "You have a +5 bonus to your passive Wisdom (Perception) and passive Intelligence (Investigation) scores." Now, passive Perception gets mentioned all over the place, but passive Investigation? Is this just for when the DM has a clue for you, but no one's said they're looking at the crime scene?

I think I'm just having a hard time coming up with examples in my mind. Is there anything in HotDQ or other published materials actually asking for passive INT checks? Has anyone used them in their game?
Passive Investigation checks were a thing in the leaked Alpha, but not in the final rules. Perhaps the rules are referencing the older concept.
 
Observant should give you a +5 to passive Intelligence (Investigation) checks for any investigative task the DM deem can be done repeatedly or when he wants to secretly determine whether you succeed without rolling dice, such as deducing the location of a hidden object or secret door for exemple.
 

DEFCON 1

Legend
Can't speak for anyone else... but I'm using Passive Investigation for traps and secret doors.

I hate, *hate*, HATE that the game uses Perception for everything. With a passion. Reading HotDQ it seemed like Perception checks (either passive or active) appeared 75% of the time, and all the other skills in the game appeared 25%. I found it just ridiculous. There's no reason why anyone would want any skill first other than Perception, it was just used so often for so many disparate things.

I've mentioned this in other threads before... but I've amended the whole process of seeing/hearing/sensing things into a quadrant.

Any passive checks to notice or sense things that might be missed while you do other things is a Wisdom check.

Any active checks to find things through actual searching and looking (IE using your Action) is an Intelligence check.

Any creature hiding that moves, makes noise, causes motion and leaves potential trails to be noticed (IE needs to make a Stealth check to be Hidden), you can add your Perception proficiency to the check to notice it (in my mind, it's a "Danger Sense".)

Anything that is an object that doesn't move, doesn't have to worry about sound, and doesn't have to make Stealth checks to remain unseen, you can add your proficiency in Investigation to the check.

And then you combine the pairs:

To sense that kobold hiding in the bushes... the DM would check your Passive Wisdom (Perception) against its Stealth check.

If you are walking through the dungeon and there's a tripwire across the hallway... the DM would check your Passive Wisdom (Investigation) check against the DC to find the trap.

On your turn, if you didn't notice the kobold passively and wanted to try and find it... you would use your action to make an Intelligence (Perception) check against the Stealth check of the kobold.

And on your turn, if you think there's a trap in front of you (perhaps the trap that was connected to the tripwire you may or may not have noticed)... you would use your action to make an Intelligence (Investigation) check.


By doing things this way... I remove the complete overabundance of Perception checks... passive and active. Plus, it gives Investigation something actually worthwhile to do. And thus for me (and my player who actually took Observant)... it makes Passive Investigation into actually a thing.
 
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GameDoc

Visitor
Most of the mental skills can be considered "always on" and treated as passive checks if the DM needs to determine if you naturally notice or recognize something. Passive perception to notice someone hiding in the corner, passive arcana to recognize out of the corner of your eye that the writing on a statue are magical runes not a foreign language, passive nature to automatically know that a tree shouldn't be growing where it is and something isn't right, etc.

I hope the DMG goes into more detail on passive checks. They are pretty handy and helpings making determinations without tipping off players while giving them a chance to not miss important details.
 

Jack7

Visitor
That Peculiar Mental State of Awareness

As a former PI who still occasionally helps out with cases I can tell you that the idea of passive investigation (although in my opinion it does not exist in the Real World in the way described by 5E rules as I'll explain in a moment) really refers to a very vital observational capability.

In real life, and the way I play it in games, it is the ability opt spot and notice and make certain basic deductions about the things you observe which may or may not have any direct relation to what you seem to be currently investigating but are either important enough in themselves to make note of or to further investigate (at a later time), or seem unrelated but either through intuition or practiced habit or what I call "the clear sense" you realize are important, and related. Things everyone else would either overlook as being non-germane or might not notice at all.

That is the way passive observation really works. And it is passive in the same sense that, let's say, a passive detection system works upon a submarine (or a passive investigation technique works in a detective's mind) - which is to say you must first be listening or observing. If you are not listening, watching, observing or paying attention then your odds of discovery are much worse, but if you are in that de-fault mental attitude or outlook I would say that you odds are not only much greater but it is extremely likely you will make such a discovery. (This takes a lot of practice and what you are actually able to successfully observe is not really a controllable phenomenon, but the state itself is controllable and becomes a natural mental state with much practice.) In certain mental states you almost guarantee it and in non-attentive states you make such discoveries almost impossible.

You must enter a sort of de-fault state (either intuitively or through many years of practice) of being observant for or about any and everything that might even possibly be important (either to your current line of inquiry, a related line of inquiry, or to simply anything "that shouldn't be there and is," or to something that "isn't there and should be." That's how it actually works. In the Real World. You must be "actively passive" like a submarine that is silent running but still attentively listening to be passively capable.

In games I've never exactly played this way (though we get pretty close) and I’ve never played the 5E rules before (I’ll stick with our current method) but as both a player (because those who DM me know I am naturally observant and well practiced in this area) or when my players are playing and they have an exceptionally observant character then I stay in this de-fault observational mode or I allow their characters to if they so wish or say they intend to do so.

In cases like that I/they either observe what is normally missed, or make associational deductions/inductions, or I/they might discover something of real importance in the area that has nothing at all to do with their current investigative pathway but that is of equal or even greater importance to another adventure or campaign.

That is to say I will sometimes plant in an environment something either related to what they are investigating but is difficult to discover, something that is only seemingly indirectly related, or something that is unrelated to their current activities but will lead them to a much larger adventure, campaign, or discovery.

I have done this often in the past and many times they have made such discoveries in places ripe for passive discovery and investigation, such as libraries or in certain ruins.

That's my take on how it really works.
 
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Duggage

Visitor
Can't speak for anyone else... but I'm using Passive Investigation for traps and secret doors.
That is how I'm going to do it too.

I was going to start a post about this regarding Dungeon Delver actually. But I'll drop this in here...

"You have advantage on Wisdom(Perception) and Intelligence(Investigation) checks made to detect the presence of secret doors." Pg. 166

Based on the following factors:
-Investigation skill stating "you might deduce the location of a hidden object" (see hidden object again below)
-Wording of Dungeon Delver citing that Investigation can detect secret doors
-Wording of Observant citing that Investigation can be used passively
-The rogue being prompted to make Int second highest "if you want to excel at Investigation"
-And lastly the wording in the sidebar next to the investigation skill wherein it says "When your character searches for a hidden object such as a secret door or a trap, the DM typically asks you to make a Wisdom(Perception) check." (the underline is mine) NOTE: "typically" does not mean always.

Based on all of that, I think I've concluded that the intention was for Investigation being able to be used instead of Perception for Int-based classes when it comes to hidden objects (e.g. secret doors and traps). That gives players two different approaches to a problem in a fashion similar to how Str and Dex can be two different approaches to hitting/damage with various weapons. You don't always have to have high Wisdom and Perception just like you don't always need high Str to hit with a melee weapon.

Perception would oppose stealth, Investigation wouldn't. But Investigation would help with research, whereas Perception wouldn't.

But for secret doors and traps, if Investigation can't be used by rogues instead of perception, then it makes investigation 90% useless and rogues should have been told to put their second stat as wisdom for perception- which of course screws their caster archtype.

Anyway, like I said, that is how I'm running it. If they come out with actual errata that says you never use Investigation for hidden objects then they have to clean it out of four places. If instead they say, "Yeah, of course the player can use whichever skill favors them more." Then they really don't have to clean up anything- or at most add "or Investigation (player choice)" to the "typically" line so that people don't read "typically" as "always".
 

Shadowspaz

Visitor
So I'm currently writing up an adventure path of my own for some friends of mine, and will be running. I found myself setting all kinds of passive Investigation DC's, and one in particular doesn't seem to have crossed anyone's minds here. Long story short, the adventurers have to go to an abandoned castle, and search for a lock-box. While searching, if none of the players specifically ask if the castle has seen recent use, I set a passive investigation dc to notice just that. Once revealed that the castle has in fact been in use, I set an active investigation dc to be able to tell who was using it. Such as soldiers, refugees, or bandits, in this case its bandits. If they notice they can avoid being in the bandits base when they get back, not really a useless ability in my opinion. I just don't really see passive investigation being used to find hidden objects, doors, or traps. Perception is for all things, objects, people. Investigation is for deduction based on what you can see, you notice the place isn't as dusty as you think it would be. There is fresh cut wood by the fire pit. Another example might be, noticing a window is broken out instead of in, like one might expect for a robbery... Though I suppose you could argue in some cases that a passive investigation could be used to notice that a room you are in should be bigger, if it shares a wall with the next. Deducting there could be a secret passage going between the two. Thus helping the player find a secret room.
 
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pukunui

Adventurer
Passive Investigation checks were a thing in the leaked Alpha, but not in the final rules. Perhaps the rules are referencing the older concept.
While passive Investigation is not specifically called out in the final rules, there is a sidebar indicating that just about any skill can be used passively by taking the modifier and adding 10.

For my purposes, I tend to only keep track of the PCs' passive Insight and Perception scores, as those seem to me to be the two skills that are more passive than active anyway. I sometimes go with passive knowledge scores, and I've also started using passive Initiative in one of my games. But I've yet to actually use passive Investigation.

My issue with the Observant feat is that it doesn't really make sense to me that someone would be better at noticing things when they're *not* actively looking for them. Surely the feat really ought to grant advantage on active checks as well as the +5 advantage-equivalent to the passive scores.
 
On the official character sheet there is really only passive perception and not passive investigation. That being said, the rules allow to apply the passive rules for all skills.

Passive Investigation is for example... the group staying in a room with lots ok books and reading through the books. Noticing that there is a hidden cipher in the books could happen passively (you don't look for a cipher but because your passive investigation is so high, you just happen to notice it while reading).
 

iserith

Magic Wordsmith
While passive Investigation is not specifically called out in the final rules, there is a sidebar indicating that just about any skill can be used passively by taking the modifier and adding 10.

For my purposes, I tend to only keep track of the PCs' passive Insight and Perception scores, as those seem to me to be the two skills that are more passive than active anyway. I sometimes go with passive knowledge scores, and I've also started using passive Initiative in one of my games. But I've yet to actually use passive Investigation.

My issue with the Observant feat is that it doesn't really make sense to me that someone would be better at noticing things when they're *not* actively looking for them. Surely the feat really ought to grant advantage on active checks as well as the +5 advantage-equivalent to the passive scores.
Consider that "passive" refers to the fact that the player is not rolling any dice, not that the character is not doing a thing actively. If you take a look at the rules on passive checks, you'll see that's what it is referring to. Passive checks are used when the DM wants to make a check secretly and/or for when the DM wants to resolve uncertainty in a task that is being performed repeatedly.

In the case of passive Investigation, a character might be trying to deduce the significance of the faded hieroglyphs on the walls of the dungeon as the party travels its halls and chambers. (That the hieroglyphs are faded and the characters are traveling is perhaps what makes the outcome uncertain.) If the character's passive Investigation is high enough, then the character is able to arrive at a chilling deduction: That these hieroglyphs warn of a terrible curse that will befall any who desecrate the inner sanctum of the dungeon at the threshold of which the party now stands.

Unlike passive Perception, passive Investigation is probably not likely to come up a bunch, though of course that depends on the DM.
 

pukunui

Adventurer
[MENTION=97077]iserith[/MENTION]: It still doesn't sit right with me that the bonus only applies to the passive score and not its equivalent active check. +5, as we know, is essentially the passive form of advantage, so I reckon that the feat ought to grant advantage on active Perception and Investigation rolls as well. Maybe that's too powerful, but then a flat +5 to passive Perception is pretty darn powerful too.
 

psychophipps

Explorer
I'm playing a variant human rogue investigator/arcane trickster and I see the Observant feat as the character is simply "switched on" all the time as stated by the actual RL investigator before (sorry, but Tapatalk makes it harder to flip back and forth to check names while posting). There are just some people that naturally notice things that most folks overlook because it doesn't occur to them to even care about them in their daily lives.
Now at 4th I will also take Keen Mind to crank the "D&D Sherlock Holmes" to 11...
 
While passive Investigation is not specifically called out in the final rules, there is a sidebar indicating that just about any skill can be used passively by taking the modifier and adding 10.
This is true, although I don't know what sidebar you're talking about, even in Basic this is spelled out in the open :)

Basic said:
Passive Checks
A passive check is a special kind of ability check that doesn’t involve any die rolls. Such a check can represent the average result for a task done repeatedly, such as searching for secret doors over and over again, or can be used when the DM wants to secretly determine whether the characters succeed at something without rolling dice, such as noticing a hidden monster.

Here’s how to determine a character’s total for a passive check:

10 + all modifiers that normally apply to the check

If the character has advantage on the check, add 5. For disadvantage, subtract 5. The game refers to a passive check total as a score.

For example, if a 1st-level character has a Wisdom of 15 and proficiency in Perception, he or she has a passive Wisdom (Perception) score of 14. The rules on hiding in the “Dexterity” section below rely on passive checks, as do the exploration rules in chapter 8.
Passive checks are not restricted to "reactive" (vs "proactive") skills only! They represent routine tasks or tasks that extend over time and may include multiple instances at different instants and locations.

So you can freely use e.g. passive charisma to determine how a PC manages to mingle well in an unfamiliar social environment, or passive Artisan's Tools check to gauge the outcomes of practicing a crafting profession (not that passive checks rules aren't restricted to skills so they could also be unskilled ability checks or tools checks).
 

Athinar

Explorer
DMG
find a secret door by actively searching the location where the door is hidden and succeeding on a Wisdom (Perception) check. To set an appropriate DC for the check, see chapter 8.
Opening a Secret Door. Once a secret door is detected, a successful Intelligence (Investigation) check might be required to determine how to open it if the opening mechanism isn't obvious. Set the DC according to the difficulty guidelines in chapter 8.

Secret Doors normally have a check of 20, a normal Passive Wisdom (Perception) will never find a secret door, but I could be wrong

PHB
If the character has advantage on the check, add 5. For disadvantage, subtract 5. The game refers to a passive
check total as a score.




 
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Psikerlord#

Explorer
I found using passive perception vs static trap Dc = fail.

So I dont use any passive stuff at all. I just roll. I also substitute wis perception with int investigation anytime the players want (their choice).

Works well.

Obs feat gives adv on perception/investigation in my game.
 
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Does the difference between a Passive Check and a Standard Check lie “in game”? This is suggested by the very term, “Passive” as opposed to “Active”. Take a Perception Check for example. The “in game” difference being that with a Passive Perception Check, the character is generally aware of his surroundings and may notice something, as opposed to with a Standard or “Active” Perception check where the character is actively searching for something and may find it. Page 177 of the PHB (in the section regarding Hiding) also hints that the difference lies “in game”. If this is the case, then when the character fails the Passive Check, he should then be able to attempt a Standard, or “Active” Check.


Or does the difference lie “out of game”, as suggested on page 175 of the PHB, under the heading of Passive Checks? The “out of game” difference being that with a Standard Check the player or the DM rolls a d20 (and adds modifiers) to determine the result, while with a Passive Check the player or the DM “takes 10” rather than actually rolling the d20 (and adds modifiers) to determine the result. In either case, the character must be actively making an attempt.

If this is the case, then the rule for Observant on page 168 that allows for a +5 bonus for Passive Checks should also allow it for Active Checks.

Conclusion:
It is unfortunate that the Player’s Handbook uses the term “Passive” to describe the “out of game” practice of “taking 10” when making an ability check. When describing the practice of "taking 10", the term “Passive Check” should be replaced with something like “Averaged Check” or “Automatic Check”. The opposite of this “Averaged Check” is a “Rolled Check” where the player or the DM actually rolls the D20 instead of “taking 10”. “Passive” should only be used to describe the “in game” situation where the character is not actively making some type of attempt. The opposite of this should be called an Active Check. Passive Checks (as opposed to Active Checks) are very often Averaged Checks (as opposed to Rolled Checks), but either a Passive Check or an Active Check could be made as a Rolled Check (by rolling the D20) or as an Averaged Check (also known as “taking 10”). In the case of a Constitution Check (such as going for long periods without food or water) there would be no difference between a Passive Check and an Active Check and only one or the other should be attempted. But in the case of a Perception Check, an Investigation Check, and possibly others, there is a definite difference, so after failing the Passive Check the character should be allowed to attempt an Active Check if he thinks of doing so. I was thinking that there should be some penalty for the Passive Check (such as a -5), but then I read the post above, written by Defcon 1. I think he was on to something. Any Passive Checks (as opposed to Active Checks, not as opposed to Rolled Checks) could use a simple Ability Check that does not include the player's Proficiency Bonus. That would, in affect, give the penalty to Passive Checks that I was considering.
I'm still digesting some of the other stuff that Defcon1 wrote, and I liked Duggage's train of thought although I don't think I entirely agree with his conclusions. I hope to get back to you on these things later.
 

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