A little off the main topic, but like many people, the whole invisibility / unseen contradiction has driven me spare at times. I know the now generally accepted interpretation seems to be that if your invisible, your unseen, not hiding, ie your location is known, but you can't be seen. That said I seem to have come full circle on this and have noticed something that I'm not sure has been mentioned before.
So bare with me as I go through the thought process.
I was looking at the weapon for warning in the DMG, which lead me to look at the Rod Of Alertness.
"While in that bright light, you and any creature that is friendly to you gain a +1 bonus to AC and Saving Throws and can sense the location of any InvisibleHostile creature that is also in the bright light."
That last sentence implies that its giving the user the power to sense the location of a hostile invisible, something that if we go with the now accepted interpretation, anyone can do.
This then lead me to take another look at the "Invisible Condition statement"
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.
Attack rolls against the creature have disadvantage, and the creature’s Attack rolls have advantage.
The important part I clearly missed when I've read that 100's of times before is:
The creature’s location "can" be detected by any noise it makes or any tracks it leaves.
It doesn't say -> The creature’s location "is" or "will be" detected by any noise it makes or any tracks it leaves.
So "can" equals "might" equals CONTEST, and you cant "contest" unless you have something you can "contest" against.
So being invisible implies you have an automatic stealth result, be it passive or active, I would go as much to say its active, roll a stealth check when you go invisible, and again whenever you doing something that might require another check, ie move, attack, talk etc.
And lets face it, magic invisibility should always be greater than someone just trying to hide in the shadows, even if they are skilled. This interpretation doesn't hurt those skilled in stealth, in fact it makes them better. It just bumps the power of invisibility.
So, I'm not sure the above has ever been brought up before, I certainly haven't come across it.
The rod lets you sense the location of any invisible creature period, even if it is hiding. Not redundant with the (possibly) default ability of everyone to sense the location of invisible creatures that are not hiding.
That said, I don't agree that there's a big difference, and honestly all of this effort to distinguish Hiding from being Invisible seems misguided to me. Being hidden means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they use Perception. Being Invisible means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they correctly perceive it by way of your tracks or sound (or presumably any of the other senses that the condition doesn't list).
That's the same thing. Those two sections describe functionally the same thing. Invisible does not say "everyone knows where you are," but it does provide that someone might know where you are even though you are invisible (so, they can strip off one of the three advantages it provides you). The main difference between Invisible and Hidden is, if someone figures out where you are while Hidden, you're no longer Hidden at all (strip off all three advantages it provides you, although you may quite likely still have (1) and (2) if you are otherwise obscured by whatever you were hiding in).
Does an Invisible creature/Hiding creature have advantage when attacking something that can't see it? Answer to both is yes.
Do attacks against an Invisible creature/Hiding creature have disadvantage when their attacker can't see them? Answer to both is yes.
Do others know what square an Invisible creature/Hiding creature is in? Answer to both is, only if they succesfully use Perception to perceive them.
Can others end your Invisible/Hiding status? 100% yes for hiding (can make you stop being hidden removing all 3 benefits), 33% yes for Invisibility (can figure out what square you're in to target but can't negate the advantage/disadvantage benefit).
They're 99% the same effin' thing, it's just that a spell like Invisibility has a different cause (casting the spell) and duration (until you make an attack or cast a spell) than Hiding's cause (make a Stealth check) and duration (until you make an attack or are actively spotted).
And "Hidden" is not a condition, so trying to draw a line between it and Invisible is comparing apples to apple-flavored-oranges.
For point 3.Above, What DC is the perception against for those who are invisible, the hidden use stealth, invisible's use? My understanding is anyone can sense the square an invisible is in, no perception required under current interpretations.
Do creatures always know the exact location of creatures that are invisible, but not hidden?
The case for:
Invisible is not the same thing as invisible and hidden. The invisible condition in PHB Appendix A explains, “The [invisible] creature's location can be detected by any noise it makes or any tracks it leaves.” PHB p177 says, “Signs of [an invisible creature] might still be noticed, and it does have to stay quiet.” Trying to avoid giving away tell-tale non-visual indicators of your location is done by taking the hide action. In discussing stealth, Jeremy Crawford says, “It’s also perfectly in keeping with the rules for a group to assume that unless a person hides, people generally know where invisible people are in combat.” (starts 29:38) then goes on to say “It's also perfectly in keeping with the rules for a group to assume that unless a person hides, people generally know where invisible people are in combat because of their movements, their sword swings, they are seeing the effect in the environment either because their weapon is clipping through bushes or they bumped up against a table as they walked by and they see the drinks wobble.” The advantages of the invisible condition are the effects of the condition itself. The biggest benefit of being invisible is that it provides you with the conditions to hide continuously instead of having to find cover all the time. And when you do attempt to hide, the stealth check is often made at advantage due to being invisible. If a creature is required to take the search action to perceive an invisible creature, then that invisible creature may as well be considered hidden as well.
The case against:
Nothing in the rules or in JC’s interview explicitly states that invisible and unhidden creatures passively give away their position—only that it can or might happen. PHB p177 says, “Signs of [an invisible creature] might still be noticed, and it does have to stay quiet,” but staying quiet can often be done simply by not doing things that make noise. The rogue Blindsense feature states, “Starting at 14th level, if you are able to hear, you are aware of the location of any hidden or invisible creature within 10 feet of you.” The 18th level ranger Feral Senses feature states in part, “You are also aware of the location of any invisible creature within 30 feet of you, provided that the creature isn’t hidden from you and you aren’t blinded or deafened.” If creatures know the location of invisible creatures automatically, then this would not need to be spelled out explicitly in these high-level class features and the usefulness of those features would be negated. The Rod of Alertness’ ability to “sense the location of any invisible hostile creature that is also in the bright light,” would not need to be pointed out if the location of invisible creatures was known by default.
How I run it at my table:
An invisible creature who is not hidden does not automatically give away their position. Any character who wishes to know the invisible creature’s position may spend their action to take the search action and attempt to perceive the invisible creature. This skill check is not made against the invisible creature’s stealth, but against a DC that I assign on the spot based on factors such as distance between the two creatures, whether the invisible creature has moved or made any actions recently that would make noise, whether the perceiving creature has sensory advantages that go beyond sight, whether the invisible creature has cast any spells that have verbal components or create effects that would indicate the caster’s position, other environmental distractions, etc. And once the invisible creature’s position has been pinpointed, the perceiving creature is able to maintain the target’s position even as it moves until the invisible target goes behind total cover or hides. If the passive perception of the perceiving creature is higher than the DC at a given time, I do not require the search action. That creature just knows where the target is. Attacks against the invisible target still have disadvantage even if the invisible creature’s position is pinpointed.
An invisible creature who is not hidden does not automatically give away their position. Any character who wishes to know the invisible creature’s position may spend their action to take the search action and attempt to perceive the invisible creature. This skill check is not made against the invisible creature’s stealth, but against a DC that I assign on the spot based on factors such as distance between the two creatures, whether the invisible creature has moved or made any actions recently that would make noise, whether the perceiving creature has sensory advantages that go beyond sight, whether the invisible creature has cast any spells that have verbal components or create effects that would indicate the caster’s position, other environmental distractions, etc. And once the invisible creature’s position has been pinpointed, the perceiving creature is able to maintain the target’s position even as it moves until the invisible target goes behind total cover or hides. If the passive perception of the perceiving creature is higher than the DC at a given time, I do not require the search action. That creature just knows where the target is. Attacks against the invisible target still have disadvantage even if the invisible creature’s position is pinpointed.
So in the above, how would you handle an invisible player who also takes the effort to perform a hide action. Would it then be based purely Stealth vs Perception, rather than perception vs a GM derived DC, even if they where in say soft mud?
The game has a mechanism for perception against invisible + hiding creatures so I use that. Moving stealthily through soft mud night or might not be considered difficult terrain, depending on the situation.
I have found that in practice, the perception vs DC concept is something I consider more often when an invisible creature does something that might bring the DC below the passive perception of perceptive characters. Players are VERY reluctant to spend their character’s precious action on searching, which is understandable.
That said, I don't agree that there's a big difference, and honestly all of this effort to distinguish Hiding from being Invisible seems misguided to me. Being hidden means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they use Perception. Being Invisible means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they correctly perceive it by way of your tracks or sound (or presumably any of the other senses that the condition doesn't list).
That's the same thing.
Being hidden means you've managed to avoid being seen and heard. Being invisible means you can't be seen. These are obviously not the same thing.
Do others know what square an Invisible creature/Hiding creature is in? Answer to both is, only if they succesfully use Perception to perceive them.
Incorrect. Perception is only necessary if there's a chance you won't notice something. Being invisible doesn't imply anything about other creature's ability to hear you. If you're making a racket, it's not going to take any special effort to know where you are.
In fairness, Jeremy Crawford has been explicit in saying that passive scores are a floor, but that only matters when an active skill check is being made. That is a distinction that only matters in combat where searching requires an action.
I believe that is the point of passive skills. It's what you do when you're not trying.
I mostly agree with this, with a caveat. "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." A passive skill check means the PLAYER does not roll a die. It does not mean that a CHARACTER is successful every time.
If you want to use passive stealth against passive perception for determining whether an unhidden invisible creature is detected by someone else, then it's certainly not the worst idea I've heard. In fact, it's better than most. I'm just pointing out there is a potential problem with using passive stealth in this way and a DM should consider that in deciding whether to use that mechanism to accomplish such a goal.
I just want to emphasize that "passive" does NOT mean the character is not doing anything or not trying. Passive refers to the PLAYER not rolling any dice. That's it. If the character is NOT taking an action that is applicable to the passive skill then the passive skill does not apply.
Here is a published example from LMoP in which a character actively searching for a trap uses their passive score as a base while a character walking along has to make an active check.
"Snare. About 10 minutes after heading down the trail, a party on the path encounters a hidden snare. If the characters are searching for traps, the character in the lead spots the trap automatically if his or her passive Wisdom (Perception) score is 12 or higher. Otherwise, the character must succeed on a DC 12 Wisdom (Perception) check to notice the trap."
In this case, passive perception is applied first IF the character is actively searching.
If the character isn't doing something that would cause the passive skill to come into play then you don't make a passive skill check. Passive has NOTHING to do with whether the character is passive or active, it has to do with whether the PLAYER is passive or active in terms of rolling dice.
So many folks seem to think that passive skills apply when the character is doing nothing ... which makes feats like observant entirely non-sensical. "Oh I can notice things better if I don't try ... " i.e. passive perception and investigation are increased by 5 ... so the character is better at figuring out puzzles or noticing things if they don't actually look? Oh, I'll close my eyes and cover my ears so that I can notice things better?
Unfortunately, even module writers have been confused by the meaning of "passive" so you can find some other published examples that take the opposite approach.
P.S. Passive perception is frequently used because in most situations, characters are ALWAYS assumed to be paying attention. The travel rules outline a few exceptions like mapping when a character is too distracted to use their passive perception but otherwise, in combat, while walking around, while exploring, characters are always paying attention to their surroundings so passive perception is almost always in play NOT because the character is doing nothing but because they are assumed to be paying attention to their surroundings unless they are explicitly doing something else.
P.P.S. As for the question on passive stealth, I would tend to use it as a baseline depending on how the character intended to move. If they want to be noisy, they are noisy. If they aren't doing anything special except moving along and trying not to make too much noise then use passive stealth (an average result) , if they are trying to hide, use a stealth roll with the passive value as a floor. If they are in a situation where they have to move quickly, time is limited or they otherwise might have complications then use a stealth roll without the passive floor. i.e. if in a situation where average can not be guaranteed then passive doesn't apply. (that is how I would tend to play it ... e.g. using perception as an action in combat, stealth in combat, making an investigation or insight check with time pressure etc ... passive values only apply if an average result makes sense or if the DM doesn't want the player to roll dice ... that is what passive means in this context.
So many folks seem to think that passive skills apply when the character is doing nothing ... which makes feats like observant entirely non-sensical. "Oh I can notice things better if I don't try ... " i.e. passive perception and investigation are increased by 5 ... so the character is better at figuring out puzzles or noticing things if they don't actually look? Oh, I'll close my eyes and cover my ears so that I can notice things better?
I don't see how anyone say this in good faith unless they simply didn't know how passive perception was meant to work. We have already established that passive scores also work as minimum results on active skill checks.
After reading your post, I agree with what you are saying, but I feel like the distinction between the two situations is purely academic. Whether a player wants to consider passive perception as noticing something even if the character isn't trying or if the player wants to look at passive perception as being representative of the character always paying attention, the end result is the same for the people sitting around the gaming table. If the DC is below the character's passive perception, the DM should tell the player that their character notices the thing. As for other passive scores, I've never been in a situation to use them in a game, so I can't say how that would work at the table. I do know I wouldn't be good with using passive stealth for the reasons I mentioned earlier in this thread.
I have seen other threads where people have said (and I think I may have even argued in favor of this back in the day) "The character needs to be actively searching for passive perception to work," and the overwhelming response has been that such an position by the DM severely kneecaps players who take the observant feat or who have high passive perception to make themselves strong at detection.
Part of the issue at hand is one of balance. JC has stated that the invisibility condition provides strong advantages in and of itself outside of the ability to be undetected. You don't want to overpower an already good ability even further by adding on too many additional benefits. That being said, from a realism standpoint, I can definitely see the case for occasionally loosing the location of an invisible person even without them hiding. An NPC or player can choose to "be quiet" without a stealth check even though it's not something that can be measured specifically. It's also easy to role play in the means of detection of the invisible party (footprints, blood trail, shuffle of boots, bumping objects etc...) If I was going to apply passives as a means of detection, I would not apply a person's direct passive perception vs. passive stealth as I think it's too powerful an addition to invisibility directly. I may allow for a flat 10+dex vs passive perception which could possibly go up or down based on surroundings as determined by the DM. Even without this mechanic, if you think the situation warrants it, you can have the invisible person get lost in the shuffle and explain it off however you want.
the base dc should be 20 they can't roll lower than 20 + there modifiers. if someone wants to attack someone invisible if they just attack its at disadvantage and a -5 penalty to the attack roll
Making an Attack Whether you’re striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has the following structure: Choose a target. Pick a target within your attack’s range: a creature, an object, or a location. Determine modifiers. The DM determines whether the target has cover and whether you have advantage or disadvantage against the target. In addition, spells, special abilities, and other effects can apply penalties or bonuses to your attack roll. Resolve the attack. You make the attack roll. On a hit, you roll damage, unless the particular attack has rules that specify otherwise. Some attacks cause special effects in addition to or instead of damage.
as the bolded part the attack is made with disadvantage (you could say they can't attack because you must choose a target/but it doesn't say "one you can see") and the -5 penalty can be removed if they roll a perception check that beats their opponent's stealth dc, but they still attack at disadvantage.
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A little off the main topic, but like many people, the whole invisibility / unseen contradiction has driven me spare at times. I know the now generally accepted interpretation seems to be that if your invisible, your unseen, not hiding, ie your location is known, but you can't be seen. That said I seem to have come full circle on this and have noticed something that I'm not sure has been mentioned before.
So bare with me as I go through the thought process.
I was looking at the weapon for warning in the DMG, which lead me to look at the Rod Of Alertness.
"While in that bright light, you and any creature that is friendly to you gain a +1 bonus to AC and Saving Throws and can sense the location of any Invisible Hostile creature that is also in the bright light."
That last sentence implies that its giving the user the power to sense the location of a hostile invisible, something that if we go with the now accepted interpretation, anyone can do.
This then lead me to take another look at the "Invisible Condition statement"
The important part I clearly missed when I've read that 100's of times before is:
The creature’s location "can" be detected by any noise it makes or any tracks it leaves.
It doesn't say -> The creature’s location "is" or "will be" detected by any noise it makes or any tracks it leaves.
So "can" equals "might" equals CONTEST, and you cant "contest" unless you have something you can "contest" against.
So being invisible implies you have an automatic stealth result, be it passive or active, I would go as much to say its active, roll a stealth check when you go invisible, and again whenever you doing something that might require another check, ie move, attack, talk etc.
And lets face it, magic invisibility should always be greater than someone just trying to hide in the shadows, even if they are skilled. This interpretation doesn't hurt those skilled in stealth, in fact it makes them better. It just bumps the power of invisibility.
So, I'm not sure the above has ever been brought up before, I certainly haven't come across it.
Cheers, let the comments fly :)
The rod lets you sense the location of any invisible creature period, even if it is hiding. Not redundant with the (possibly) default ability of everyone to sense the location of invisible creatures that are not hiding.
That said, I don't agree that there's a big difference, and honestly all of this effort to distinguish Hiding from being Invisible seems misguided to me. Being hidden means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they use Perception. Being Invisible means that (1) attacks against you have disadvantage, and (2) you have advantage to attacking others, and (3) no one knows what square you are in unless they correctly perceive it by way of your tracks or sound (or presumably any of the other senses that the condition doesn't list).
That's the same thing. Those two sections describe functionally the same thing. Invisible does not say "everyone knows where you are," but it does provide that someone might know where you are even though you are invisible (so, they can strip off one of the three advantages it provides you). The main difference between Invisible and Hidden is, if someone figures out where you are while Hidden, you're no longer Hidden at all (strip off all three advantages it provides you, although you may quite likely still have (1) and (2) if you are otherwise obscured by whatever you were hiding in).
They're 99% the same effin' thing, it's just that a spell like Invisibility has a different cause (casting the spell) and duration (until you make an attack or cast a spell) than Hiding's cause (make a Stealth check) and duration (until you make an attack or are actively spotted).
And "Hidden" is not a condition, so trying to draw a line between it and Invisible is comparing apples to apple-flavored-oranges.
dndbeyond.com forum tags
I'm going to make this way harder than it needs to be.
For point 3.Above, What DC is the perception against for those who are invisible, the hidden use stealth, invisible's use? My understanding is anyone can sense the square an invisible is in, no perception required under current interpretations.
Do creatures always know the exact location of creatures that are invisible, but not hidden?
The case for:
Invisible is not the same thing as invisible and hidden. The invisible condition in PHB Appendix A explains, “The [invisible] creature's location can be detected by any noise it makes or any tracks it leaves.” PHB p177 says, “Signs of [an invisible creature] might still be noticed, and it does have to stay quiet.” Trying to avoid giving away tell-tale non-visual indicators of your location is done by taking the hide action. In discussing stealth, Jeremy Crawford says, “It’s also perfectly in keeping with the rules for a group to assume that unless a person hides, people generally know where invisible people are in combat.” (starts 29:38) then goes on to say “It's also perfectly in keeping with the rules for a group to assume that unless a person hides, people generally know where invisible people are in combat because of their movements, their sword swings, they are seeing the effect in the environment either because their weapon is clipping through bushes or they bumped up against a table as they walked by and they see the drinks wobble.” The advantages of the invisible condition are the effects of the condition itself. The biggest benefit of being invisible is that it provides you with the conditions to hide continuously instead of having to find cover all the time. And when you do attempt to hide, the stealth check is often made at advantage due to being invisible. If a creature is required to take the search action to perceive an invisible creature, then that invisible creature may as well be considered hidden as well.
The case against:
Nothing in the rules or in JC’s interview explicitly states that invisible and unhidden creatures passively give away their position—only that it can or might happen. PHB p177 says, “Signs of [an invisible creature] might still be noticed, and it does have to stay quiet,” but staying quiet can often be done simply by not doing things that make noise. The rogue Blindsense feature states, “Starting at 14th level, if you are able to hear, you are aware of the location of any hidden or invisible creature within 10 feet of you.” The 18th level ranger Feral Senses feature states in part, “You are also aware of the location of any invisible creature within 30 feet of you, provided that the creature isn’t hidden from you and you aren’t blinded or deafened.” If creatures know the location of invisible creatures automatically, then this would not need to be spelled out explicitly in these high-level class features and the usefulness of those features would be negated. The Rod of Alertness’ ability to “sense the location of any invisible hostile creature that is also in the bright light,” would not need to be pointed out if the location of invisible creatures was known by default.
How I run it at my table:
An invisible creature who is not hidden does not automatically give away their position. Any character who wishes to know the invisible creature’s position may spend their action to take the search action and attempt to perceive the invisible creature. This skill check is not made against the invisible creature’s stealth, but against a DC that I assign on the spot based on factors such as distance between the two creatures, whether the invisible creature has moved or made any actions recently that would make noise, whether the perceiving creature has sensory advantages that go beyond sight, whether the invisible creature has cast any spells that have verbal components or create effects that would indicate the caster’s position, other environmental distractions, etc. And once the invisible creature’s position has been pinpointed, the perceiving creature is able to maintain the target’s position even as it moves until the invisible target goes behind total cover or hides. If the passive perception of the perceiving creature is higher than the DC at a given time, I do not require the search action. That creature just knows where the target is. Attacks against the invisible target still have disadvantage even if the invisible creature’s position is pinpointed.
"Not all those who wander are lost"
I think the only answer to that is "per-case ruling".
An invisible creature walking through piles of leaves - everyone knows where it is.
An invisible creature breathing heavily or wearing noisy clothing - everyone knows where it is.
An invisible creature flying - maybe call for a Wisdom check to notice the sound of breathing or equipment.
An invisible, unbreathing, incorporeal, flying creature - no-one knows where it is (or even that it is there in the first place).
So in the above, how would you handle an invisible player who also takes the effort to perform a hide action. Would it then be based purely Stealth vs Perception, rather than perception vs a GM derived DC, even if they where in say soft mud?
The game has a mechanism for perception against invisible + hiding creatures so I use that. Moving stealthily through soft mud night or might not be considered difficult terrain, depending on the situation.
I have found that in practice, the perception vs DC concept is something I consider more often when an invisible creature does something that might bring the DC below the passive perception of perceptive characters. Players are VERY reluctant to spend their character’s precious action on searching, which is understandable.
"Not all those who wander are lost"
Being hidden means you've managed to avoid being seen and heard. Being invisible means you can't be seen. These are obviously not the same thing.
Incorrect. Perception is only necessary if there's a chance you won't notice something. Being invisible doesn't imply anything about other creature's ability to hear you. If you're making a racket, it's not going to take any special effort to know where you are.
The Forum Infestation (TM)
I just want to emphasize that "passive" does NOT mean the character is not doing anything or not trying. Passive refers to the PLAYER not rolling any dice. That's it. If the character is NOT taking an action that is applicable to the passive skill then the passive skill does not apply.
Here is a published example from LMoP in which a character actively searching for a trap uses their passive score as a base while a character walking along has to make an active check.
"Snare. About 10 minutes after heading down the trail, a party on the path encounters a hidden snare. If the characters are searching for traps, the character in the lead spots the trap automatically if his or her passive Wisdom (Perception) score is 12 or higher. Otherwise, the character must succeed on a DC 12 Wisdom (Perception) check to notice the trap."
In this case, passive perception is applied first IF the character is actively searching.
If the character isn't doing something that would cause the passive skill to come into play then you don't make a passive skill check. Passive has NOTHING to do with whether the character is passive or active, it has to do with whether the PLAYER is passive or active in terms of rolling dice.
So many folks seem to think that passive skills apply when the character is doing nothing ... which makes feats like observant entirely non-sensical. "Oh I can notice things better if I don't try ... " i.e. passive perception and investigation are increased by 5 ... so the character is better at figuring out puzzles or noticing things if they don't actually look? Oh, I'll close my eyes and cover my ears so that I can notice things better?
Unfortunately, even module writers have been confused by the meaning of "passive" so you can find some other published examples that take the opposite approach.
P.S. Passive perception is frequently used because in most situations, characters are ALWAYS assumed to be paying attention. The travel rules outline a few exceptions like mapping when a character is too distracted to use their passive perception but otherwise, in combat, while walking around, while exploring, characters are always paying attention to their surroundings so passive perception is almost always in play NOT because the character is doing nothing but because they are assumed to be paying attention to their surroundings unless they are explicitly doing something else.
P.P.S. As for the question on passive stealth, I would tend to use it as a baseline depending on how the character intended to move. If they want to be noisy, they are noisy. If they aren't doing anything special except moving along and trying not to make too much noise then use passive stealth (an average result) , if they are trying to hide, use a stealth roll with the passive value as a floor. If they are in a situation where they have to move quickly, time is limited or they otherwise might have complications then use a stealth roll without the passive floor. i.e. if in a situation where average can not be guaranteed then passive doesn't apply. (that is how I would tend to play it ... e.g. using perception as an action in combat, stealth in combat, making an investigation or insight check with time pressure etc ... passive values only apply if an average result makes sense or if the DM doesn't want the player to roll dice ... that is what passive means in this context.
I don't see how anyone say this in good faith unless they simply didn't know how passive perception was meant to work. We have already established that passive scores also work as minimum results on active skill checks.
After reading your post, I agree with what you are saying, but I feel like the distinction between the two situations is purely academic. Whether a player wants to consider passive perception as noticing something even if the character isn't trying or if the player wants to look at passive perception as being representative of the character always paying attention, the end result is the same for the people sitting around the gaming table. If the DC is below the character's passive perception, the DM should tell the player that their character notices the thing. As for other passive scores, I've never been in a situation to use them in a game, so I can't say how that would work at the table. I do know I wouldn't be good with using passive stealth for the reasons I mentioned earlier in this thread.
I have seen other threads where people have said (and I think I may have even argued in favor of this back in the day) "The character needs to be actively searching for passive perception to work," and the overwhelming response has been that such an position by the DM severely kneecaps players who take the observant feat or who have high passive perception to make themselves strong at detection.
"Not all those who wander are lost"
Part of the issue at hand is one of balance. JC has stated that the invisibility condition provides strong advantages in and of itself outside of the ability to be undetected. You don't want to overpower an already good ability even further by adding on too many additional benefits. That being said, from a realism standpoint, I can definitely see the case for occasionally loosing the location of an invisible person even without them hiding. An NPC or player can choose to "be quiet" without a stealth check even though it's not something that can be measured specifically. It's also easy to role play in the means of detection of the invisible party (footprints, blood trail, shuffle of boots, bumping objects etc...) If I was going to apply passives as a means of detection, I would not apply a person's direct passive perception vs. passive stealth as I think it's too powerful an addition to invisibility directly. I may allow for a flat 10+dex vs passive perception which could possibly go up or down based on surroundings as determined by the DM. Even without this mechanic, if you think the situation warrants it, you can have the invisible person get lost in the shuffle and explain it off however you want.
the base dc should be 20 they can't roll lower than 20 + there modifiers. if someone wants to attack someone invisible if they just attack its at disadvantage and a -5 penalty to the attack roll
Making an Attack
Whether you’re striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has the following structure:
Choose a target. Pick a target within your attack’s range: a creature, an object, or a location.
Determine modifiers. The DM determines whether the target has cover and whether you have advantage or disadvantage against the target. In addition, spells, special abilities, and other effects can apply penalties or bonuses to your attack roll.
Resolve the attack. You make the attack roll. On a hit, you roll damage, unless the particular attack has rules that specify otherwise. Some attacks cause special effects in addition to or instead of damage.
as the bolded part the attack is made with disadvantage (you could say they can't attack because you must choose a target/but it doesn't say "one you can see") and the -5 penalty can be removed if they roll a perception check that beats their opponent's stealth dc, but they still attack at disadvantage.