Invisible Objects and Spell Effects under RAW

jgsugden

Adventurer
In 5E, invisible creatures are not hidden by default. Even though you're invisible, until you take the hide action, your location is obvious due to your sounds, tracks, etc... We don't all like the rule, but it is there.

What about invisible objects or spell effects? If a cup is made invisible, what needs to be done to detect the presence of it on a table? What does a creature need to do to detect an arcane eye or rope trick portal?

From what I can tell, you fall back to generic rules of setting a perception DC to perceive something that is hard to spot under the RAW - perhaps a DC of somewhere between 15 and 25. Is that how you'd handle the PCs attempting to detect an arcane eye, a rope trick portal, a scrying sensor or an invisibile object on a table?
 

Phazonfish

Explorer
As far as I can tell, unless it impacts something around it (i.e. this table was made invisible, but it was dragged to this corner of the room, so scratches are visible on the floor) you cannot see the presence of something invisible. If you want to find something like this, you would have to touch it, smell it, or (if it gives off noise) hear it. I would never say a player could even possibly detect a scrying sensor with a naked eye.
 

Oofta

Title? I don't need no stinkin' title.
I rule that there has to be something that can be logically detected. That could be anything from cobwebs to motes of dust to nothing at all.

So there isn't really anything like a standard. I just set the DC based on how I envision the scene.
 

BigBadDM

Explorer
I shake my head at topics like this. why do we have to have rules or 'opinions' on non-existence rules.

1) Don't like a rule, change it. Our group just allows a 'free action' to hide for invisible/heavily obscured creatures. We don't like the rule, so we change it.

2) If there is no rule - such as objects and whatnot. Adjudicate one. That's one of the jobs as a DM.

3) just use common sense. why try to shoehorn a 'fall-back' rule.

4) if they need to know, give them clues. If they don't why bother. Detect Magic is also overlooked.

5) make the story go forward and have fun.
 
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5ekyu

Adventurer
Invisible means cannot be seen. So if your observer is trying to find it by sight alone, that fails unless there is reason.

As for DC, it would vary as to specifics. Is your invisible mug on a table in the rain? Is it in sn old room with dust? A lot of bugs? Breeze blowing stuff?

It all matters.
 

Harzel

Explorer
I shake my head at topics like this. why do we have to have rules or 'opinions' on non-existence rules.

1) Don't like a rule, change it. Our group just allows a 'free action' to hide for invisible/heavily obscured creatures. We don't like the rule, so we change it.

2) If there is no rule - such as objects and whatnot. Adjudicate one. That's one of the jobs as a DM.

3) just use common sense. why try to shoehorn a 'fall-back' rule.

4) if they need to know, give them clues. If they don't why bother. Detect Magic is also overlooked.

5) make the story go forward and have fun.
Careful with the head shaking - you may injure yourself. OP mentioned how they thought about a situation not covered by the rules and asked for others' thoughts, presumably looking for different/better options. Completely legit; exactly the kind of thing this forum is for.*

* In addition to Survivor threads, which we all know is the main reason the forum exists.
 

Salthorae

Imperial Mountain Dew Taster
In 5E, invisible creatures are not hidden by default. Even though you're invisible, until you take the hide action, your location is obvious due to your sounds, tracks, etc... We don't all like the rule, but it is there.

What about invisible objects or spell effects? If a cup is made invisible, what needs to be done to detect the presence of it on a table? What does a creature need to do to detect an arcane eye or rope trick portal?

From what I can tell, you fall back to generic rules of setting a perception DC to perceive something that is hard to spot under the RAW - perhaps a DC of somewhere between 15 and 25. Is that how you'd handle the PCs attempting to detect an arcane eye, a rope trick portal, a scrying sensor or an invisibile object on a table?
It would really depend on the environment the invisible object was in as @5ekyu points out below.

There could be a reason that the PC's could detect the presence of an otherwise invisible object.

For your example of an Arcane Eye. Sure, they're invisible, but they are also moving around potentially. Do they disturb the air when they move (up to you as the DM). If they do, is there smoke in the room when it's moving around? Haze or Fog? Is there just wind noise however faint?

Invisible means cannot be seen. So if your observer is trying to find it by sight alone, that fails unless there is reason.

As for DC, it would vary as to specifics. Is your invisible mug on a table in the rain? Is it in sn old room with dust? A lot of bugs? Breeze blowing stuff?

It all matters.
As for DC... well I'd got back to the long-winded discussion from the Proficiency to AC thread.

There is no call to check if the DM rules that it is impossible to detect. If a DM thinks it's possible, then roll and set a DC. For something like an invisible object but that is somehow interacting with the elements of the room to give some clues as to its location, I'd probably start at 20 or 25 depending on the elements and the size of the object, and then go up from there.
 

BigBadDM

Explorer
Careful with the head shaking - you may injure yourself. OP mentioned how they thought about a situation not covered by the rules and asked for others' thoughts, presumably looking for different/better options.
A little injury is often good for the soul.

But think about this question... if a sword is invisible in the middle of the desert that no one visits, does its existence matter?

If a cup on a table is invisible, does it matter to the story or the plight of the problem? If it does then give clues and well enough of them for them to find the cup. If it doesn't then why bother with the theorem at hand.

Another way to look at it... if the player's NEED to find a secret door to enter the next room (and it is the only way to proceed further), then DCs and skill checks matter not. They find the door.

The way forward should always be attainable for the PCs. If the elements don't matter...then think why they are occurring in the first place.

If someone wants to give the feeling of being watched (as Arcane Eye), just tell the players they feel like they are being watched. Then they can cast true seeing or detect magic to help deduce the problem, if they are so inclined. Give them clues that it appears some force knows where they are going before they get there.

Not everything needs to have a DC roll in the game; especially when there is no interaction with the players.
I shake my head at these things because... well they don't need answers. If they did they would be rules in the book.

But if one wants to go with that route and have everything rolled. Well, just have them do a perception or investigation check. Set the DCs per the baseline guidelines. Easy ->10, Medium -> 15, Hard ->20, etc.
 
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Charlaquin

Goblin Queen
From what I can tell, you fall back to generic rules of setting a perception DC to perceive something that is hard to spot under the RAW - perhaps a DC of somewhere between 15 and 25. Is that how you'd handle the PCs attempting to detect an arcane eye, a rope trick portal, a scrying sensor or an invisibile object on a table?
Depends on the player’s approach to attempting to find it. Any attempt to find it that relies purely on sight would fail without a check. But an approach that relies on touch, or on making deductions based on contextual clues might require a check, and in that case hard (15) to nearly impossible (25) depending on the specific approach seems reasonable. Some approaches, such as feeling in exactly the spot it’s in, might succeed without a roll.
 

jgsugden

Adventurer
Assume that the invisible items are neither in the "must be found" or "are irrelevant if they are found". They are instead in the "useful if found" category.

Other thoughts? Any RAW we're missing for invisible objects?
 

Ashrym

Adventurer
The only RAW I can think of is perception checks based on sight auto-fail. Beyond that it's the approach of the players and DM's interpretation on how hard a check should be.
 

Oofta

Title? I don't need no stinkin' title.
The definition of invisibility is from the perspective of a creature, so I only look at the parts I've bolded:
An invisible creature is impossible to see without the aid of magic or a special sense. For the purpose of hiding, the creature is heavily obscured. The creature's location can be detected by any noise it makes or any tracks it leaves.

So if the only way to detect it is visual? Not going to happen. It's impossible. You have to literally touch it or interact with it in some way.

Other than that it depends on the object. A wall or big enough might be detectable (at a very high DC) because of sound bouncing off of it. A mechanical device such as a clock could be making sound. Otherwise there has to be something in the environment external to the object that can be detected. But it will be impossible to detect visually.
 
In 5E, invisible creatures are not hidden by default. Even though you're invisible, until you take the hide action, your location is obvious due to your sounds, tracks, etc... We don't all like the rule, but it is there.

What about invisible objects or spell effects? If a cup is made invisible, what needs to be done to detect the presence of it on a table? What does a creature need to do to detect an arcane eye or rope trick portal?

From what I can tell, you fall back to generic rules of setting a perception DC to perceive something that is hard to spot under the RAW - perhaps a DC of somewhere between 15 and 25. Is that how you'd handle the PCs attempting to detect an arcane eye, a rope trick portal, a scrying sensor or an invisibile object on a table?
Consider a cup. If it's not moving and is invisible then sight won't reveal it's existence.
 

Oofta

Title? I don't need no stinkin' title.
Consider a cup. If it's not moving and is invisible then sight won't reveal it's existence.
Exactly. Unless you bump the table and hear something fall over or see a clean circle on an otherwise dusty table or cobwebs attached to nothing you aren't going to detect it.

Unless, of course it starts talking to you.
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Exactly. Unless you bump the table and hear something fall over or see a clean circle on an otherwise dusty table or cobwebs attached to nothing you aren't going to detect it.

Unless, of course it starts talking to you.
View attachment 115403
My problem with invisible items is that once players learn of their existence there are simple mundane ways to check for them at the cost of a trivial amount of time.

Then there's also the detect magic spell/ritutal.

In short, static invisibility (unless part of a puzzle) is pretty boring.
 

Oofta

Title? I don't need no stinkin' title.
My problem with invisible items is that once players learn of their existence there are simple mundane ways to check for them at the cost of a trivial amount of time.
That and as was posted above, what purpose does the item serve in the game? Even assuming it's just a "nice to have" the DM sets whatever DC makes sense and then justifies being able to detect it because of some external environmental factor. That can be anything from automatic (you touch it after you see a noisy bird sitting on nothing) to nearly impossible (moats of dust in the air moving oddly).
 
That and as was posted above, what purpose does the item serve in the game? Even assuming it's just a "nice to have" the DM sets whatever DC makes sense and then justifies being able to detect it because of some external environmental factor. That can be anything from automatic (you touch it after you see a noisy bird sitting on nothing) to nearly impossible (moats of dust in the air moving oddly).
For a single item in the campaign done that way, that's probably fine - since at that point it's probably more of a puzzle. But if invisible items are encountered more than once then players will start checking for invisible items everywhere.
 

Esker

Explorer
In 5E, invisible creatures are not hidden by default. Even though you're invisible, until you take the hide action, your location is obvious due to your sounds, tracks, etc... We don't all like the rule, but it is there.

What about invisible objects or spell effects? If a cup is made invisible, what needs to be done to detect the presence of it on a table? What does a creature need to do to detect an arcane eye or rope trick portal?

From what I can tell, you fall back to generic rules of setting a perception DC to perceive something that is hard to spot under the RAW - perhaps a DC of somewhere between 15 and 25. Is that how you'd handle the PCs attempting to detect an arcane eye, a rope trick portal, a scrying sensor or an invisibile object on a table?
In the case of an object created or made invisible by a spell, wouldn't the caster's spell DC be the obvious choice of DC to detect its presence, provided there is a plausible source of evidence about its existence?

Perception checks based on sight automatically fail, but if the object is moving (like an arcane eye), there might be disturbances to the air, which perception (at disadvantage) could pick up on. But then figuring out what it actually is might require further action (detect magic, see invisibility, maybe an arcana check to make the inference).

If it's a static object in a room, I'd probably reveal its existence as part of a sufficiently high investigation roll to search the room rather than a perception check, since finding it is more of an inference than it is a sensory thing.

But in each case, I'd use the caster's DC, with advantage or disadvantage applied to the check depending on the situation.
 
In the case of an object created or made invisible by a spell, wouldn't the caster's spell DC be the obvious choice of DC to detect its presence, provided there is a plausible source of evidence about its existence?
IMO. It's either invisible or not. Better casters don't make objects more invisible than worse ones.

Perception checks based on sight automatically fail, but if the object is moving (like an arcane eye), there might be disturbances to the air, which perception (at disadvantage) could pick up on. But then figuring out what it actually is might require further action (detect magic, see invisibility, maybe an arcana check to make the inference).
right

If it's a static object in a room, I'd probably reveal its existence as part of a sufficiently high investigation roll to search the room rather than a perception check, since finding it is more of an inference than it is a sensory thing.
I wouldn't unless they had indicated they were investigating the table the invisible cup was sitting on and doing more than looking at it while doing so.

But in each case, I'd use the caster's DC, with advantage or disadvantage applied to the check depending on the situation.
I would not. There are not degrees of invisibility. There is invisible and there is not. I would solely base the DC on environmental factors and players stated actions.
 

Esker

Explorer
IMO. It's either invisible or not. Better casters don't make objects more invisible than worse ones.
Yeah, I suppose with the invisibility spell cast on a creature, the perception threshold is the stealth roll rather than the caster's DC. But in the case of a spell like arcane eye, since the eye doesn't have stats and the spell doesn't give a DC, it makes sense to me to say that the better the caster, the less the eye disturbs its environment. But maybe an even better way to handle it would be to have the caster make a stealth check using their casting stat in place of dexterity.

I wouldn't unless they had indicated they were investigating the table the invisible cup was sitting on and doing more than looking at it while doing so.
I think it comes down to what level of detail the DM likes to give of the environment, and what level of player specificity they require for something like searching a room. The investigation skill is supposed to capture the character's ability to make inferences from evidence, and it could well be that the character could do a better job than the player at knowing what to look at. It's a bit like when a character makes a persuasion or deception check; how much do you let the player's facility with rhetoric influence the outcome if they're playing a character that's much more skilled than they are?
 

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