Is passive perception always on?

Quote from SunIsGettingRealLow96589 >>

And besides if the hidden character is behind total cover, they cant shoot their enemies, and enemies cant shoot them, so it doesnt matter.  What matters is when the assasin who hid behind total cover comes to 3/4 cover or comes out in the open to attack you. At which point, if passive perceptiin is always on, that when you percieve them, and they cannot attack with advantage.

Actually, 3/4 cover is explicitly mentioned as being good enough to potentially conceal your location by successfully hiding.  As such, when the assassin who hid behind total cover (and has not yet been passively or actively found) comes to 3/4 cover to attack you, that attack does not reveal their location until the attack hits or misses as per the rules for Unseen Attackers and Targets combined with the rules for hiding.  If the passive perception did not already detect this creature, it would not help them in that situation.

"that text does NOT say that that is the only way to find a creature,"

The way the rules work, the only thing you can do are things the rules say you can do. So, if the rules say you can misty step as a bonus action, then you can misty step as a bonus action. The rules will NEVER say that will be the only way to misty step, cause some subclass or feature might let you do it someway else.

BUT, unless therr is a rule somewhere that says you can misty step as a reaction, then all there is is the rule that says you can misty step as a bonus action, then bonus action is the only way you can do it.

The rules for Hide willl NEVER say that Search Action/Perception Check is the ONLY way to find someone hidden, but unless there is actual text rules that give another way, then there is no other way.

So unless there is a rule that says you can "find" someone who is hidden using your passive perception, then it isnt raw.  It may be rai. But if its rai, then raw needs errata to clarify 

Quote from up2ng >>

Quote from SunIsGettingRealLow96589 >>

And besides if the hidden character is behind total cover, they cant shoot their enemies, and enemies cant shoot them, so it doesnt matter.  What matters is when the assasin who hid behind total cover comes to 3/4 cover or comes out in the open to attack you. At which point, if passive perceptiin is always on, that when you percieve them, and they cannot attack with advantage.

 

Actually, 3/4 cover is explicitly mentioned as being good enough to potentially conceal your location by successfully hiding.  As such, when the assassin who hid behind total cover (and has not yet been passively or actively found) comes to 3/4 cover to attack you, that attack does not reveal their location until the attack hits or misses as per the rules for Unseen Attackers and Targets combined with the rules for hiding.  If the passive perception did not already detect this creature, it would not help them in that situation.

My comment was in response to 

"You can find a hidden creature behind Total Cover if you meet its Hide DC with a Wisdom (Perception) check or if the DM uses your Passive Perception instead and it's high enought to do so."

I.e. total cover.

To which i was agreeing that you could find someone behind total cover. 

Quote from SunIsGettingRealLow96589 >>

The way the rules work, the only thing you can do are things the rules say you can do.

First of all, this is false.  If there had to be a rule for every possible thing that you could do, then the rulebook would be infinitely long.  Where is the rule that says that you can paraglide?  Where is the rule that says that you can swing back and forth while grabbing a chandelier?  Where is the rule that says that you can bake a loaf of bread?  There are an infinite number of things that creatures can do that are not explicitly stated within the rules.

Quote from SunIsGettingRealLow96589 >>

So unless there is a rule that says you can "find" someone who is hidden using your passive perception, then it isnt raw.  It may be rai. But if its rai, then raw needs errata to clarify 

No, the 2024 rules made a deliberate effort to avoid repeating things in multiple places.  There is no reason for the text of the Hide action to address this at all.  The Hide action provides a mechanism for determining how to adjudicate a Search action to find a hidden creature.  There are already rules elsewhere that establish that Passive Perception is used to notice creatures and objects when not actively searching.  So, setting the DC explicitly for the Search action also implicitly sets the DC for Passive Perception, by rule.  This is because the DC is a property of the thing being found, not a property of the method of finding it.  Any time it is possible to actively search for something you might also discover it passively.  That's RAW.

A similar issue arises when people like to claim that taking the Hide action "only" gives you the Invisible condition.  This is false.  It's just that the other rules and mechanics for hidden creatures are located elsewhere -- therefore, they do not need to be written into the text for the Hide action.  The Hide action establishes that you become a hidden creature.  In the rules for Unseen Attackers and Targets we learn that the location of a hidden creature is unknown specifically because they are both unseen and unheard.  Therefore, the act of becoming hidden means that you become both unseen and unheard.  An additional consequence is that you also gain the invisible condition -- that detail is not given anywhere else, so it has to exist within the text for the Hide action.  In the 2024 rules, this sort of thing happens all over the place because the authors tried very hard to save word count by avoiding redundancy.