DesEuler's page

[...]If Pharasma has decided that the target’s time has come or the target doesn’t wish to return, this ritual automatically fails[...]

The resurrectee has a choice.

So they have no idea if it's a Champion resurrecting them as an ally or a demon resurrecting them to torture them?

Correct. In PF2E, the resurrectee does not know anything about the caster (unlike in PF1E) unless Pharasma (aka the GM) chooses to divulge information to the resurrectee before they make their decision to accept the resurrection.

Magical hazards with a minimum proficiency rank cannot be found with detect magic at all.

Excellent contribution. I actually missed that line. Thanks!

Detect Magic does, indeed, not work for detect hazards or traps. Only items, objects, ongoing effects, and the like.

Personally I feel that is disappointing, but it is undeniably what the rules say.

Detect Magic almost never works for magical traps. When it works, these traps are either 1 level or less, or obviously and visibly magical and not stealthy.

Huh? Do you have a source for this claim or has this just been your experience? Or a GM running it wrong?

DesEuler wrote:

If someone spots it, anyone in the party that has the necessary skills immediately know the methods by which to disarm it,

That's interesting, I've been making people roll Recall Knowledge to identify how to disable a hazard. What's the rules basis for this approach? Follow up question, how many actions does it take for a disable attempt if it doesn't use thievery and the hazard statblock fails to specify it?

I will be honest, there is some ambiguity in the rules for this bit (because there are none). It is hashed out here in the forums - and probably in other threads.

One interpretation, and the one I adhere to, is:
There isnt mention of a Recall Knowledge check to discern how to Disable; nor is there coverage of Traps, Hazards, or Haunts in any Recall Knowledge entry, for any skill. Recall Knowledge: Crafting doesn't even mention mechanical traps. This interpretation claims that omission implies there is no roll needed/appropriate.

Think of it like this, using a real life example...

• - Despite never encountering one firsthand, the average person probably knows of the existence of bear traps, roughly what one looks like, and how one is triggered (has the required Perception proficiency-rank requirement to detect)
• - They might not notice one hidden under leaves, though (Perception roll vs the Stealth DC)
• - Even if they saw it and knew what it was, the average person probably wouldnt know how to Disable one without triggering it.
• - A Hunter/person trained in Survival (the needed proficiency rank and skill to Disable) would have been exposed to traps such as this, or perhaps even used this type of trap, before and have a better idea of how to disarm it (instantly knows it is Bear Trap and that they can use their Survival skills Disable it).
• - Alternatively, a person confident in their precision and reflexes (trained in Thievery) could intentionally trigger the trap in a way nobody gets hurt.
  

Pathfinder is much higher fantasy, so the 'average' adventurer would be exposed to significantly more peculiar traps (many of which are magical in nature) than a real life example could depict.
As such, exposure to the types of hazards and traps in PF2E are represented by Perception proficiency-rank, a WIS stat. And knowledge of how to Disable a hazard is represented by proficiency in the relevant Disable Device skills for that specific hazard.

As a side note, a GM could (at their discretion) offer insight as to the difficulty to Disable were the player to use the skill they believe they can Disable the Device with (if it is Easy, Hard, etc. for their level; based on the DC of the Hazard and the 10-5 DCs by Level table).
Using the Bear trap example, the Hunter might knows what it is and but only roughly how to Disable it (indicative of a Hard adjustment).

@DesEuler, I believe it's been stated that Pharasma actually knows if a soul is going to be resurrected (although perhaps less reliably since the death of Aroden) and intentionally delays final judgement until after then.

Sorry, I missed this until now. You are correct. Pharasma has no qualms with delaying judgement or resurrection magic. There are even some undead she is apathetic to the existence of (depending on their pretext...similar reasoning to dhampirs), so the cultist could just come back on his own if the GM wanted.

I think once judgement has happened it's impossible to resurrect someone. Like even deity level magic wont do it IIRC.

This, however, is mostly correct. Players in PF2E currently have no way to do this (to my knowledge); however, spells like Judgement Undone have existed in previous editions.

When a creature is judged, it is trasformed into a Petitioner. There is also some murkiness surrounding them, where it could be possible (through planar travel+modify memory+change shape, etc.) to 'recover' a judged soul Petitioner, but no explicit method to recover a judged soul has been mentioned thusfar in PF2E.
Pharasma does have the ability to undo her own judgement, though. Convincing her to do so, however, is an entirely different story and in the GMs hands at that point. Performing some Monitor-related task on her behalf that an Olethros, or perhaps Morrigna, is incapable of seems appropriate.

If the soul's Petitioner dies (by GM discretion), it is final. Not even deity level entities, at least not Pharamsa, can recover the soul. Urgathoa might have a way, but I doubt it? Or perhaps a deity with domain over the Positive Energy plane might be able to? But I didnt major in Positive Energy Plane lore. :)

PF2E makes no distinction. It gives that freedom to the GM. The GM is Pharasma and gets the final say in whether or not a any creature comes back. The GM (aka Pharasma) can depart some wisdom to influence the resurrectees decision, if you (the GM aka Pharasma) wish.

if you're a CE cult leader or something and a LG Cleric of Torag is trying to resurrect you...then you might very decide it's a trick/trap and refuse to come back.

In this case, you the GM (aka Pharasma) have the luxury of deciding if the cult leader knows its the PCs that just killed him that are trying to resurrect him (and whether he wants to wait for another person to resurrect him) or if its another entity that might be hostile to the cult leader.

That is what the rules say. As for advice on how to run it, I would say: Tell a story. If you as GM think it would be cooler to allow the players to resurrect the cultist to interrogate him/torture him then do it. It might give the players some satisfaction that their plans were worth it or not thwarted because the barbarian hit him too hard. If you the GM dont like the plan and it doesnt match your story, then tell the players that the spell didnt work. You can choose to disclose that Pharasma prohibited it or that the cultist doesnt want to return, if you wish - perhaps via a Recall Knowledge: Pharasma Lore check.

When any creature dies, they immediately arrive in The Boneyard. I envision this as a 'check out' line of a bunch of dead people waiting to talk to Pharasma.

Once a player declares they have no intention of being resurrected, then Pharasma has judged that players character and they move out to an appropriate outer sphere, as determined by the GM if it is necessary. Only incredibly powerful magic can bring the character back at that point.
Such magic would directly oppose Pharasmas judgement; as such, she would directly intervene in such cases - or at the very least send a Morrigna to recollect the soul. So any creature using such magic should fully anticipate combatting CR15+ to deity level threats.

While the PC is still in the 'check out' line, if someone attempts to resurrect that PC, that PC basically hears a little bell in their head and can choose to go back to being alive or stay in line to be judged. Neither option opposes Pharasmas will, you simply came to see her too soon; she will see you eventually.

If you want, GM has discretion for Pharasma (aka the GM) to provide insight on who is attempting to bring the players character back, but the player doesn't have a way to gain that knowledge on their own. They are dead, they have no power here - barring extraneous means by which they arrived in The Boneyard.

Depends on how the resurrectee is being resurrected.

If Resurrect, the resurrectee doesn't really really know anything beyond what they would know about the person standing directly in front of him when he woke up from being dead.

If the resurrectee didn't know anything about the caster of the Ritual before they died, after they are resurrected, that is still the case.

Furthermore, a waterfall is considered an Object. Here is an explicit example that confirms this. Therefore, Detect Magic and Read Aura would work on a waterfall.

Item and Object are synonymous terms; however, their exact definition is not explicitly defined anywhere in the rules and is a frequent topic of discussion on the forums.

Detect Magic only tells you that something in the room, other than what is on you and your buddies, is magical. The Rank 4 version tells you what square the strongest magical source is in. You can omit it from your next casting to find other squares containing strong magical sources. This will allow you to get the number of magical effects in the room. Nothing more.

For example, let there be a room with both a Magical Trap and a waterfall that is falling up. Detect Magic at Rank 1 would automatically alert you to the presence of something magical. Detect Magic at Rank 4 would tell you there are in fact 2 magic sources, which squares they are in, and which of the two is stronger. This could prompt you to take the Seek action (GM rolls vs stealth DC of the Trap) to see if you can spot a Trap. If someone spots it, everyone in the party knows which squares to avoid and anyone in the party that has the necessary skills immediately know the methods by which to disarm it, but not what the trap does if it is triggered (which is discovered via Identify Magic). As for the waterfall falling up, it is pretty obviously magical, so no roll would be necessary to spot it.

Once you know something in the room is magical (or in attempt to find which thing in that square is magical), Read Aura tells you what school of magic the thing you targeted is (unless its illusion). If the waterfall is an illusion, you might detect a conjuration or necromancy (if its a blood waterfall) aura instead - matching whatever the illusions intended effect was. In a less conspicuous example, like an illusory stone wall, it could emit no aura whatsoever when you Read Aura - which could cause you to overlook it. Read Aura ensures that, when you attempt to Identify Magic, you are investigating something that is in fact magical.

Once you know what thing is magical, you can spend 10 minutes inspecting that singular thing attempting to Identify Magic, after which the GM rolls a secret check against the DC of the effect. Then tells you what you know based on the Identify Magic level of success.

Areas and Dimensions
Default is 3 dimensional unless otherwise specified.

Regarding earth spells, they have the trait

Effects with the earth trait either manipulate or conjure earth. Those that manipulate earth have no effect in an area without earth. Creatures with this trait consist primarily of earth or have a magical connection to that element. Planes with this trait are mostly solid, with caverns and other hollow pockets.

As such, Earth cone effects would still extend into the ground (provided the effect produced ignores Line of Effect), but unless a creature is burrowed, or otherwise underground, its irrelevant. Additionally, the Earth cone would, typically, not extend into the air because it is a square without earth and thus has no effect - as per the Earth trait.

Cone effects follow the same 1,3,3 or 1,2,3 cone area (for a 15-foot cone) when determining height, when necessary.

Notably 20ft burst does not mean a 20ft radius cylinder; just because a creature is 20ft in the air, does not mean it would be hit by a 20ft burst, unless it was centered directly below the creature.

The little bit: 'adjacent to a flat surface' and 'rise up'

Seems to imply, for similar reasons that a Fire spell effect does not travel into the ground, Black Tentacles only emits a burst in a singular direction - up (GM discretion: 'up' vs 'away from the surface').

Surface Definition
The structure trait provides several examples of a surface. Notably, it explicitly defines 'water and other nonsolids' as a surface, but does not explicitly say that air is one. So with a very liberal reading of the RAW, a GM could allow it if they wanted to consider it a 'nonsolid surface'.

Ruling
I would consider air, water, earth, etc. to be mediums through which an effect travels and the surface to be where that medium changes. You could not place Black Tentacles inside the mediums, but you could place it on the surfaces - notably only non-vertical ones since the spell only travels up (a more liberal reading of the rules could say 'away' from the surface instead of only up, subject to GM discretion). As such, barring extraneous circumstances, such as an upside-down world or a zone affected by Reverse Gravity, the spell would always be travelling up into the air from a more solid surface such as water, earth, metal, etc.

TLDR

• Air isnt a surface, so Black tentacles cant have its origin be in the air.
  
• It only travels up (GM Discretion)
  
• It affects a 20ft radius semisphere from the origin.

GM Discretion
As others have stated, this is in the realm of GM adjudication as the term Object is not explicitly defined, so expect results to vary; however...

You repeatedly cast the same spell while moving at half speed. Typically, this spell is a cantrip that you want to have in effect in the event a combat breaks out, and it must be one you can cast in 2 actions or fewer. In order to prevent fatigue due to repeated casting, you’ll likely use this activity only when something out of the ordinary occurs.

You can instead use this activity to continue Sustaining a Spell or Activation with a sustained duration. Most such spells or item effects can be sustained for 10 minutes, though some specify they can be sustained for a different duration.

Even if a GM were so kind as to allows the player to Target an entire building, the party would need to find it in 10 minutes or less.

Adjudication and Supporting Rules
The closest I have found to an explicit definition is the Animate Object Ritual
which has Targets: 1 Object and the ritual description provides some examples.

So using Animate Object as a guideline, it appears (my interpretation of the RAI) as the level of the ritual goes up, so too does the size of Object you can choose as a viable Target.

Using Bulk rules of creatures gives:
Rank 2 Ritual - Can Target a Large 2x2 Silverware Swarm - Bulk 12
Rank 5 Ritual - Can Target a Huge 3x3 Statue - Bulk 24
Rank 8 Ritual - Can Target a Gargantuan 4x4 Trebuchet - Bulk 48

Since this is a Ritual, my opinion is that using these numbers are actually fairly generous if you were to apply them to spells. Or at the very least, my opinion is that to Target larger Objects requires the use of a more powerful resource - such as a higher Rank spell slot.

Under these parameters, a expansive building would be beyond the scope of a Rank 3 Locate spell. Perhaps a small hut, though. Other objects that fall within the bulk parameters given the spell Rank would also qualify.

Worth noting...

When making a Strike that adds your Intelligence modifier on your attack roll due to Devising a Stratagem, you deal an additional 1d6 precision damage.

So if you get the bonus from Quicksilver, you would lose the bonus damage from Strategic Strike.

As members of the Pathfinder Society, characters have automatic access to many uncommon options

...
As stated in the section introduction, all characters have access to the magic items in the Magic Items section on page 117, as well as the items, familiars and spells on pages 120-121.

There are no familiars or spells on pages 120 or 121, only items; the familiars and spells are on pages 122 and 123 (with some items).

As written, the familiars and spells on pages 122 and 123 are not usable in PFS Organized Play. Is this intended or was the access adjustments supposed to extend to page 123?

I'm not sure I fully understand your question.

My intention for the question is how to run an ambush using block initiative for circumstances when you have many enemies and rolling individual initiatives can be overwhelming. My current method is to preroll. Another method I have seen is to group a few of the enemies and roll once for that group.

It's also bad form as a GM to delay actions so the enemy gets 6 characters worth of actions back to back, because it can be very hard for players to react to that kind of action block. As you can totally just use all 6 characters actions to gang up one PC.

...
It honestly goes against the "unwritten rules" of "sportsmanlike" conduct of being a GM.

The sportsmanlike conduct remark is appreciated; The scenario you described does indeed sound like bad form. I believe it is a responsibility of a GM to enhance the experience of the table they are running for the players they are running it for. Which is an underlying motive for this question being posted.

It sounds like you ultimately want to know if you can justify using one initiative roll while the NPCs might be actively using stealth.

I am not asking for justification of anything. I am simply asking what rules, if any, exist to address block initiative with Avoid Notice (stealth for initiative).

I think delaying is a tactical decision that should be enemy dependent. Mindless enemies for example, should not be using tactics, in my opinion.
I am not sure there is a rule that supports that, but I think there is?

I would be more likely to use delay and similar combat tactics with intelligent enemies. I would use blocked initiative or roll for everyone and delay to the slowest for a more cohesive unit, such as wolves, other animals that hunt in packs, or a military regiment being led by a commander. I would also narrate the commander barking orders.

Its also important to operate off what the NPCs actually know. If they are all invisible, for example, coordinating would not be practical.

Another idea I have seen proposed is to use the troop template.

Im looking at rolling a group of enemies together citing the following rule.

The GM rolls initiative for anyone other than the player characters in the encounter. If these include a number of identical creatures, the GM could roll once for the group as a whole and have them take their turns within the group in any order. However, this can make battles less predictable and more dangerous, so the GM might want to roll initiative for some or all creatures individually unless it’s too much of a burden.

Mechanically, this is slightly better than rolling for each enemy, then delaying until they can all act together and could make for some interesting ambush dynamics.

But I am unsure of how this interacts with Avoid Notice or Stealth for Initiative.
The only thing I can find discouraging this is the Quiet Allies feat which lets the players roll a group Stealth roll but specifically says it does not apply to initiative rolls. So the system seems to want to discourage this.

Can anyone provide any concrete rules that either allow or prohibit Avoid Notice group iniative rolls?

I want to poll some opinions on rolling a single initiative for a group of enemies when the enemies are a coordinated unit.

The rule supporting this is in

The GM rolls initiative for anyone other than the player characters in the encounter. If these include a number of identical creatures, the GM could roll once for the group as a whole and have them take their turns within the group in any order. However, this can make battles less predictable and more dangerous, so the GM might want to roll initiative for some or all creatures individually unless it’s too much of a burden.

Mechanically, this is as if the enemies rolled and all delayed until they were ready to act together; however, they only roll once instead of rolling X number of times taking the lowest, so this is technically a tad better for the enemies.

I am particularly interested in Pathfinder Society play ramifications.

Interpretation 2 makes a lot of 'sense' in a casual sense, insofar as that it doesn't follow that a glass wall should naturally block calling down a lightning bolt from the sky, or purely visual effect, or an effect that creates something at a specific point.

I personally like and prefer this interpretation and its implications, whether we agree or not. Because...

Line of Effect wrote:

When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability.

stops being a true statement once nearly every spell that isn't a projectile can now be cast regardless of LoE.

this only applies in the rare circumstances that you would be able to target a creature you do not have Line of Effect to. Which usually is not the case, because targeting requires...

The target must be within the spell’s range, and you must be able to see it (or otherwise perceive it with a precise sense) to target it normally. At the GM’s discretion, you can attempt to target a creature you can’t see, as described in Detecting Creatures on pages 465–467.

Since vision is, almost exclusively, the only Precise Sense, you usually would not be able to target a creature (or area) behind a solid barrier (read: That you do not have Line of Effect to).

So the implications of the second interpretation literally only apply if you are casting through glass or using a different Precise Sense; hence, you usually need Line of Effect.

Pathfinder doesn't parse "usually" quite like a mathematician might parse predicate logic.

I am, in fact, looking at the wording as a mathematician would, because I am a mathematician.

The way to parse it is an opinion and one that citing rules cannot really change. So in this regard, we will simply have to agree to disagree, not too surprisingly.

We still have the two interpretations:
1. Line of Effect to your target is required by all spells
2. Line of Effect to your target is required only if the spell produces an effect that would be blocked by a solid barrier.

I do not want this forum to become one with 200 post like the other thread which has already discussed both of these interpretations extensively. So I am content leaving the summarized versions of both interpretations in this thread for those that do not want to read the entirety of the other thread. I don't think it is worth reviving that old thread over a matter of difference in parsing preference.

Errenor wrote:

Absolutely all spells require Line of effect (unless otherwise explicitly stated).

You need to provide citation for the bolded claim. The rules do not say this.

Sorry, I forgot to bold a few words in the clarification request. Here it is updated.

No. I absolutely and definitely don't need to.

Yes you do, in a rules forum, so that we can deliberate over what rule you are bringing up.

I am left to infer we have a division on the definition of the wording 'usually need' from Line of Effect.

When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability. This is called a line of effect.

As a native English speaker, 'usually need' does not mean 'must have', to me.

By your definition of 'usually', they could simply have omitted 'usually' from the rule and just said 'you need' instead of 'you usually need'.

As for how I would adjudicate the encounter, the rogue could technically use stealth while standing directly in front of the Deculi without cover or anything else.

The Stealth skill is designed to use Hide for avoiding visual detection and Avoid Notice and Sneak to avoid being both seen and heard. For many special senses, a player can describe how they’re avoiding detection by that special sense and use the most applicable Stealth action. For instance, a creature stepping lightly to avoid being detected via tremorsense would be using Sneak.

In some cases, rolling a Dexterity-based Stealth skill check to Sneak doesn’t make the most sense. For example, when facing a creature that can detect heartbeats, a PC trying to avoid being detected might meditate to slow their heart rate, using Wisdom instead of Dexterity as the ability modifier for the Stealth check. When a creature that can detect you has multiple senses, such as if it could also hear or see, the PC would use the lowest applicable ability modifier for the check.

In this case, you could use Int as the stat while trying to douse yourself with water and trying to make your body temperature and you clothes the same temperature as your surroundings, effectively making you imperceptible.

As for Invisibility... I do not think you will be able to find an actual rule supporting this, but I would rule that it is intended for the visible spectrum - normal vision, not IR. So the Invisibility spell would actually be completely irrelevant for this encounter.

The GM rolls your Stealth check in secret and compares the result to the Perception DC of each creature you’re observed by but that you have cover or greater cover against or are concealed from. You gain the circumstance bonus from cover or greater cover to your check.

Success: If the creature could see you, you’re now hidden from it instead of observed. If you were hidden from or undetected by the creature, you retain that condition.

At the end of your movement, the GM rolls your Stealth check in secret and compares the result to the Perception DC of each creature you were hidden from or undetected by at the start of your movement.

You become observed as soon as you do anything other than Hide, Sneak, or Step.

Success: You’re undetected by the creature during your movement and remain undetected by the creature at the end of it.

As for the rogues turn, Invisibility would not grant the Undetected condition since it only affects the visible spectrum (interpretations may differ). So while he could use the sneak action, unless he was already hidden or better (such as by using the situation presented above), he would still be Observed. Once he gets around the corner, he could Hide, if he wanted to, and apply the the scenario I mentioned above (dousing his body with water, cooling of his clothes, etc to Foil the IR sense). I would require Int to be used instead of Dex (per the Stealth with Other Senses rule - GM discretion for which stat to use). He would at that point be Hidden by the Deculi, provided he succeeded. If he wanted to become Undetected, he would now have to use the Sneak action and beat the DC.

The GM attempts a single secret Perception check for you and compares the result to the Stealth DCs of any undetected or hidden creatures in the area or the DC to detect each object in the area (as determined by the GM or by someone Concealing the Object). A creature you detect might remain hidden, rather than becoming observed, if you're using an imprecise sense or if an effect (such as invisibility) prevents the subject from being observed.

Critical Success: If you were searching for creatures, any undetected or hidden creature you critically succeeded against becomes observed by you. If you were searching for an object, you learn its location.

Success: If you were searching for creatures, any undetected creature you succeeded against becomes hidden from you instead of undetected, and any hidden creature you succeeded against becomes observed by you. If you were searching for an object, you learn its location or get a clue to its whereabouts, as determined by the GM.

Now the Deculi would have to use a Seek action to find the rogue, potentially making the rogue Observed or Hidden depending on the roll.

For Foil Senses, you still need to be hidden or better at the start of the action. Its debatable whether Invisibility trumps IR. Again, I would rule it does not, so he was not hidden at the beginning of his sneak action and thus would not get the Stealth roll or Undetected condition. He may still have cover or otherwise be untargetable while a wall persist between him and the Deculi, though.

One last additional note, if the rogue was using the Avoid Notice Exploration Activity (basically meaning he is always sneaking, which he probably was)

You attempt a Stealth check to avoid notice while traveling at half speed. If you have the Swift Sneak feat, you can move at full Speed rather than half, but you still can’t use another exploration activity while you do so. If you have the Legendary Sneak feat, you can move at full Speed and use a second exploration activity. If you’re Avoiding Notice at the start of an encounter, you usually roll a Stealth check instead of a Perception check both to determine your initiative and to see if the enemies notice you (based on their Perception DCs, as normal for Sneak, regardless of their initiative check results).

So the Deculi does not roll Perception when the rogue enters the room. The GM rolls a secret Stealth check (be sure to ask for Int stat instead of Dex stat stealth bonus) for the rogue and compares it to the Deculi's Perception DC to determine if the rogue was initially undetected.

On a slightly related matter, if there are other enemies in the room that have vision, the rogue would still use Int for his Stealth/Initiative roll because he is having to compensate for the special sense (this is an interpretation, not quite definitive - see below).

When a creature that can detect you has multiple senses, such as if it could also hear or see, the PC would use the lowest applicable ability modifier for the check.

My interpretation of this is you are supposed to use the lowest relevant stat when multiple senses apply to the Stealth check.

Invisibility only blocks vision.

I was actually originally believing Invisibility would block all precise senses, but after looking at the rules on it, found that it only blocks vision.

While invisible, you can't be seen. You're undetected to everyone. Creatures can Seek to attempt to detect you; if a creature succeeds at its Perception check against your Stealth DC, you become hidden to that creature until you Sneak to become undetected again. If you become invisible while someone can already see you, you start out hidden to the observer (instead of undetected) until you successfully Sneak. You can't become observed while invisible except via special abilities or magic.

So the Invisibility spell trumps vision - you become Invisible which specifically calls out vision. However, it also explicitly makes you undetected to everyone. Special abilities such as the ability to precisely sense without vision (see Detecting Creatures below), True Sight or magic such as See Invisibility, which specifically interact with illusions and invisible creatures, would meet the exception spelled out in the Invisible rules and allow the creature to become observed. Imprecise senses are insufficient to grant an observed condition, so this is only relevant for precise senses that are not vision.

In most circumstances, you can sense creatures without difficulty and target them normally. Creatures in this state are observed. Observing requires a precise sense, which for most creatures means sight, but see the Detecting with Other Senses sidebar (page 465) for advice regarding creatures that don’t use sight as their primary sense. If you can’t observe the creature, it’s either hidden, undetected, or unnoticed, and you’ll need to factor in the targeting restrictions. Even if a creature is observed, it might still be concealed.

If a monster uses a sense other than vision, the GM can adapt the variables that keep its foes from being detected to equivalents that work with the monster’s senses. For example, a creature that has echolocation might use hearing as a primary sense. This could mean its quarry is concealed in a noisy chamber, hidden in a great enough din, or even invisible in the area of a silence spell.

By RAW, you usually have to use an imprecise sense (see below) to detect an invisible creature - the exception being that you have another precise sense. Hearing, for example, counts as a common imprecise sense for detecting an invisible creature. But an Imprecise Sense is insufficient to grant the Observed condition.

Hearing is an imprecise sense—it cannot detect the full range of detail that a precise sense can. You can usually sense a creature automatically with an imprecise sense, but it has the hidden condition instead of the observed condition. It might be undetected by you if it’s using Stealth or is in an environment that distorts the sense, such as a noisy room in the case of hearing. In those cases, you have to use the Seek basic action to detect the creature. At best, an imprecise sense can be used to make an undetected creature (or one you didn’t even know was there) merely hidden—it can’t make the creature observed.

Using Stealth with Other Senses

The Stealth skill is designed to use Hide for avoiding visual detection and Avoid Notice and Sneak to avoid being both seen and heard. For many special senses, a player can describe how they’re avoiding detection by that special sense and use the most applicable Stealth action. For instance, a creature stepping lightly to avoid being detected via tremorsense would be using Sneak.

In some cases, rolling a Dexterity-based Stealth skill check to Sneak doesn’t make the most sense. For example, when facing a creature that can detect heartbeats, a PC trying to avoid being detected might meditate to slow their heart rate, using Wisdom instead of Dexterity as the ability modifier for the Stealth check. When a creature that can detect you has multiple senses, such as if it could also hear or see, the PC would use the lowest applicable ability modifier for the check.

So you could use an imprecise sense (or a precise sense other than vision) to automatically detect an invisible creature (unless 'it is using Stealth or is in an environment that distorts the sense, such as a noisy room in the case of hearing'), because the Invisible condition only calls out vision - it would be hidden, though, in the case of an imprecise sense. A creature that just cast Invisibility was likely not using stealth at the time, so even though they become Undetected, they immediately become detected again due to the additional senses.

Lastly, the Disappearance spell serves as proof by contradiction for invisibility because Disappearance specifically calls out all senses.

The target becomes undetected, not just to sight but to all senses, allowing the target to count as invisible no matter what precise and imprecise senses an observer might have.

Referencing the first sentence of the Invisible condition, originally it only cared about vision. Disappearance says all senses. So you no longer have the ability to automatically detect the creature by using a sense other than vision.

Absolutely all spells require Line of effect (unless otherwise explicitly stated).

You need to provide citation for the bolded claim. The rules do not say this.

The inferred requirement that ALL spells require Line of Effect is leftover from Pathfinder 1E which reads:

You must have a clear line of effect to any target that you cast a spell on or to any space in which you wish to create an effect. You must have a clear line of effect to the point of origin of any spell you cast.

When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability.

Pf2e is much less strict. The term usually is used in PF2E, not must. It is not a requirement, but is usually needed for the spell to function. 'Must' demands the spell to explicitly declare it is an exception. 'Usually' says it is relative to the spell.

And all targeting (with Targets entry and most 'target' words unless they messed up wordings which happens) also requires Line of sight (unless otherwise explicitly stated).

This is also not what is actually stated in the rules.

The target must be within the spell’s range, and you must be able to see it (or otherwise perceive it with a precise sense) to target it normally. At the GM’s discretion, you can attempt to target a creature you can’t see, as described in Detecting Creatures on pages 465–467. If you fail to target a particular creature, this doesn’t change how the spell affects any other targets the spell might have.

Some effects require you to have line of sight to your target

Line of Sight is not explicitly required for targeting; it is only potentially required for resolving the effect of the spell and clarifies the meaning of seeing/sight if it is mentioned in the spell description and states what counts as 'sight' (precise sense and not blocked by a solid barrier). See Dimension Door for an example.

Targeting only requires the ability to precisely sense the target (Line of Sight also requires the target 'not be blocked by a solid barrier'). This is particularly relevant for targeting invisible creatures or creatures you can only imprecisely sense.

In most circumstances, you can sense creatures without difficulty and target them normally. Creatures in this state are observed. Observing requires a precise sense... If you can’t observe the creature, it’s either hidden, undetected, or unnoticed, and you’ll need to factor in the targeting restrictions.

You can choose a target that you cannot precisely sense but it suffers the hidden, undetected, or unnoticed targeting restrictions.

This actually makes me realize in my previous post I initially said Line of Sight was required, when it is not. Only the ability to precisely sense, which I did state/correct in my conclusion.

Concerning area effects, you ignored this:

Line of Effect wrote:

When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability.

'Usually' just equals my "unless otherwise explicitly stated" and nothing more.

That is the division in the the interpretations. It has been discussed ad nauseam in this thread, as was mentioned earlier.

I have a question related to this, what about spells likes Wall of Fire? Do I need line of effect/sight for the whole 60ft wall to make it that long? Or do I only need line of effect/sight for the square in the grid where the wall starts?

This has come up plenty of times and I don't know how to deal with it.

Using my understanding, you would need Line of Sight for as much of the wall as you would like to create, however, Line of Sight is not restricted to vision.

As long as you can precisely sense the area (as described in Perception on page 464) and it is not blocked by a solid barrier (as described in Cover on pages 476–477), you have line of sight.

Cover applies only if your path to the target is partially blocked. If a creature is entirely behind a wall or the like, you don't have line of effect and typically can't target it at all.

...
Usually, the GM can quickly decide whether your target has cover. If you're uncertain or need to be more precise, draw a line from the center of your space to the center of the target's space. If that line passes through any terrain or object that would block the effect, the target has standard cover
...
Your GM might let you reduce or negate cover by leaning around a corner to shoot or the like. This usually takes an action to set up, and the GM might measure cover from an edge or corner of your space instead of your center.

For the bold portion of Cover, you could still target something with an imprecise sense, you just would not have Line of Effect and therefore you options would be very limited. Since you could only target it with an imprecise sense, you also would not have Line of Sight.

For example, if there’s a solid wall between the origin of a fireball and a creature that’s within the burst radius, the wall blocks the effect

So, if you were trying to summon a wall where there are trees in the way, for example, then you could not produce the effect in a square you could not precisely sense and the spell would not create an effect where the tree is, instantaneously. Since the spell has a duration (unlike fireball), the spell's effect would simply be suppressed as long as the tree was there, because the effect is being blocked by a solid barrier - the square is unable to be effected.

To rationalize it, imagine yourself running through the wall of fire. You are burned by it, but fire does not appear inside your body. The moment you are through the wall, fire reappears where you ran through.

You could rule that the tree is being damaged by fire, but that is a question for a different thread.
The spell Wall of Fire specifically says:

Any creature that crosses the wall or is occupying the wall's area at the start of its turn takes 4d6 fire damage.

If you could prove that a tree counts as a creature, then the tree would simply be 'in the way' and would be taking damage, but the damage is probably inconsequential to its HP within the duration of the spell. Similarly, though, if the tree moves (or entirely burns to ashes), fire returns.

My understanding is that SOME spells require line of effect, as is exactly stated in the Line of Effect entry.

When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability.

The 'usually' comes from how most of the spells interact.

An arc of lightning leaps from one target to another. You deal electricity damage equal to 1d4 plus your spellcasting ability modifier.

The italicized portion demands Line of Effect.

Fireball, however, states:

A roaring blast of fire appears at a spot you designate

The blast simply appears there. It doesn't travel to the target, so there is no need for Line of Effect, only Line of Sight.

Only people within Line of Effect of the origin of the blast would be affected, though.

In an area effect, creatures or targets must have line of effect to the point of origin to be affected. If there’s no line of effect between the origin of the area and the target, the effect doesn’t apply to that target.

@Guntermench
That is how I am interpreting it as well under the assumption that Line of Effect is an additional requirement to Line of Sight.

So they would cast the spell, but no effect would occur.

The alternative interpretation, mentioned in that earlier thread, would result in the spell being cast and having potentially a limited effect, depending on the spell.

Just wanted to clarify one of the interpretations and what would happen to the spell slot, if there was any rules to cite about it, etc.

What if you try to cast a spell without knowing you do not Line of Effect?

For example, if there was an invisible wall you did not know about between you and the target when you tried to cast the spell. Do you simply lose the spell?

In the Learn a Spell activity it clarifies the flavor text by replacing "gain access" with "learn" in the results section:

Critical Success: You expend half the materials and learn the spell.
Success: You expend the materials and learn the spell.
Failure: You fail to learn the spell but can try again after you gain a level. The materials aren’t expended.
Critical: Failure As failure, plus you expend half the materials.