xanathars perception of spells

[NaughtyTiger]

As noted in the Player’s Handbook, you normally don’t know that a spell has been cast unless the spell produces a noticeable effect.

Can anyone point to where that is noted in the PHB?

[Aquillion]

In the "targets" subsection of the spellcasting chapter:


Unless a spell has a perceptible effect, a creature might not know it was targeted by a spell at all. An effect like crackling lightning is obvious, but a more subtle effect, such as an attempt to read a creature’s thoughts, typically goes unnoticed, unless a spell says otherwise.

Admittedly a slightly weird place to put it, but it's there. (Technically it only says the spell's target might know they were affected by a spell, but the implication is clear.)

And yes, this makes the 14th level benefit of the Enchantment school a bit confusing. It does work with Charm Person (which specifically says they know they were charmed), but it only matters for spells like that that explicitly state your target knows - otherwise it's assumed they don't.

[NaughtyTiger]

If that is the extent of it, then per the PHB, you can whisper your spells. You can cast a spell behind full cover in a room full of enemies and no one would know.
If you were under greater invisibility, then you could be in the middle of the room chanting away, in an inaudible whisper and drop fireball.

You cannot Ready an Action to trigger to "attack a caster after a spell is cast" after the spell goes off (let alone at the start of casting) if there is no specific visible spell effect (and you ain't the target)

[Aquillion]

Whispering your spells is dubious; some DMs allow it, others don't. I've also seen DMs allow Bards to conceal spellcasting by working it into a performance (I feel allowing a performance check to do this would encourage them to actually be good at performance, which is currently a pretty weak skill for them.)

For spells without verbal components, however, you can definitely hide it by using stealth, provided there's a way to slip out of view without being noticed - if they can't see you, material and somatic components don't matter. Notably, illusions almost all lack verbal components, probably for this exact reason (they wouldn't be nearly so useful if you couldn't cast them stealthily.)

Another option, of course, is to mislead your target about which spell you cast, though this assumes they can't make a good Arcana check.

As an aside, some people worry that it devalues subtle spell. Personally I feel they're worried too much - Subtle Spell is a third level feature, not some sort of capstone, and it also allows you to cast when silenced or immobilized. I also feel "but class X gets Y!" is a really bad argument, because it makes people weaker every time a new class is published. There should legitimately be multiple ways of doing most things worth doing; the game should be about creativity and interesting plans, not solely about "push button X, get effect Y." So I think it's a bad argument to state that the fact that Sorcerers can reliably and automatically hide their spellcasting means nobody else can do so by any means.

But the flip side to this is that for clever solutions to be clever, they shouldn't be one-size-fits-all. One thing I like about the "conceal spellcasting within a performance" trick for bards is that it only works sometimes - you can't just spontaneously break into a performance whenever you want or people will get suspicious, especially since music and magic are pretty heavily linked for bards to begin with (ie. they won't necessarily know you used magic, but they might suspect it, especially if you started to perform at a key moment and then things mysteriously went your way.)

Similarly, "I hide in the crowd and try to conceal my spellcasting in the noise they're making" is a reasonable justification for a stealth check; whereas I wouldn't allow just "stealth check to cast silently" with no further explanation. Whispering your spells runs into that problem - it's a universal solution to something that should require creative solutions (unless you're a Sorcerer, who can just choose to hit an auto-succeed button, of course.)

[NaughtyTiger]

Whispering your spells is dubious;

The PHB is clear the perception is not from the verbal component, only the effect.

I totally missed that quote in the "disrupt thread".

[Aquillion]

Sort of! I don't necessarily disagree that whispering spells might be allowed per RAW, but it's worth realizing that many DMs disallow it. The specific text is:


Most spells require the chanting of mystic words. The words themselves aren't the source of the spell's power; rather, the particular combination of sounds, with specific pitch and resonance, sets the threads of magic in motion.Now, pitch is not the same thing as volume, so it's really up to your DM to decide how loud it needs to be.

It's worth comparing this to the rules for the gestures:


Somatic: Spellcasting gestures might include a forceful gesticulation or an intricate set of gestures. Unlike the verbal component (which makes no mention of volume), the rules emphasize that the gestures must be "forceful", which means you probably want to be Stealthed if you intend to cast without being noticed.

Of course, the exact gestures and sounds are ambiguous, so it's unclear if you can conceal it within some other actions - like the "Bard hides hide spellcasting inside a foreign-language performance" example I gave above. I'd say you can do that, but other people could use passive Perception to notice something is off ("those gestures look awfully specific") or get a Knowledge: Arcana check to recognize a spell being cast.

For spells with no verbal components (or if your DM allows you to cast your spells at a low volume and you're too distant to be heard), if you're outside of combat, not the focus of attention, and not pressed for time, you could also just say that you wait until your target looks away and then cast.

Another PC could also make a distraction - if verbal components are a problem, possibly one loud enough to drown your spellcasting out. For example, your Fighter and your Cleric could have a huge shouting match while you charm the mark.

The hardest thing to conceal is generally the material components (hence the "reaches for their spell component pouch" example in the other thread.) Slight of hand could do it pretty straightforwardly, though.

Also, aside - note that Subtle Spell does not eliminate material components. A lot of DMs ignore or waive this, but it's a pretty big deal, since so many spells use them. If people know you're a caster, reaching for your spell component pouch is a dead giveaway.

[Lunali]

Sort of! I don't necessarily disagree that whispering spells might be allowed per RAW, but it's worth realizing that many DMs disallow it. The specific text is:

Now, pitch is not the same thing as volume, so it's really up to your DM to decide how loud it needs to be.

Needing the right pitch does, however, eliminate the possibility of whispering. You may or may not be able to do it quietly, but in order to control pitch, you actually need to vocalize it.


The hardest thing to conceal is generally the material components (hence the "reaches for their spell component pouch" example in the other thread.) Slight of hand could do it pretty straightforwardly, though.

Also, aside - note that Subtle Spell does not eliminate material components. A lot of DMs ignore or waive this, but it's a pretty big deal, since so many spells use them. If people know you're a caster, reaching for your spell component pouch is a dead giveaway.

Which is why a lot of casters rely on a focus instead, much easier to hide the fact that your hand brushed against something at your belt, than that you reached into a component pouch. My personal favorite is the staff, sure it's obvious that you have the staff, but no one can tell whether you're just holding it or using it to cast a spell.

[DissidentWizard]

Pretty much everything Aquillion said is gold. Or platinum. That's 10 gold. Everything Aquillion said is 10 gold.

Dms will all rule differently and AL will rule it's own way too but ya, I think the creativity portion has a lot of room for reward within the bounds of the rules. Bards making performances and arcane tricksters casting spells among a crowd are great ways to incorporate the aspects of stealth casting into the game without overshadowing subtle casting (an aside I agree with Aquillion whole heartedly). As stated though, make sure it's within reason. Its situational, and typically a contested check.

[Unoriginal]

NaughtyTiger, you should check the whole rule section on the subject. There are three parts to the rules:



Many spells create obvious effects: explosions of fire, walls of ice, teleportation, and the like. Other spells, such as charm person, display no visible, audible, or otherwise perceptible sign effects, and could easily go unnoticed by someone unaffected by them. As noted in the Player’s Handbook, you normally don’t know that a spell has been cast unless the spell produces a noticeable effect.

This cover the perception of a spell after they've been cast. A spell once cast is only perceivable if it has a noticeable effect, which is not the case for a spell such as Charm Person.



But what about the act of casting a spell? Is it possible for someone to perceive that a spell is being cast in their presence? To be perceptible, the casting of a spell must involve a verbal, somatic, or material component. The form of a material component doesn’t matter for the purposes of perception, whether it’s an object specified in the spell’s description, a component pouch, or a spellcasting focus.

This cover how the *action of casting the spell* can be possible to perceive. Answer: if it has a component or more, it can be perceptible. Of course, the persons around still need to be able to perceive the signs.



If the need for a spell’s components has been removed by a special ability, such as the sorcerer’s Subtle Spell feature or the Innate Spellcasting trait possessed by many creatures, the casting of the spell is imperceptible. If an imperceptible casting produces a perceptible effect, it’s normally impossible to determine who cast the spell in the absence of other evidence.

And this cover how you can make the casting of the spell not perceptible. You'll note that there is no such thing as "whispering the spell" or anything like that, the text deliberately says that you need a special ability for it.


So as you see, the Xanathar's already has all the answers on your interrogations, for this subject.

[jh12]

But the flip side to this is that for clever solutions to be clever, they shouldn't be one-size-fits-all. One thing I like about the "conceal spellcasting within a performance" trick for bards is that it only works sometimes - you can't just spontaneously break into a performance whenever you want or people will get suspicious, especially since music and magic are pretty heavily linked for bards to begin with (ie. they won't necessarily know you used magic, but they might suspect it, especially if you started to perform at a key moment and then things mysteriously went your way.)

It's like you've never seen a musical. Bursting out into song is never inappropriate.

This is pretty close to one of the descriptions of a bard in action at the start of the class description.


Laughing as she tunes her cittern, a gnome weaves her subtle magic over the assembled nobles, ensuring that her companions’ words will be well received.

[Aquillion]

Needing the right pitch does, however, eliminate the possibility of whispering. You may or may not be able to do it quietly, but in order to control pitch, you actually need to vocalize it.Yeah, I would say that you have to at least be loud enough that someone near you could hear it - you can't mutter it under your breath. But I don't think you have to shout it, either, so it's reasonable to chant it low enough that any moderately-loud noise or distraction can drown you out.

(The other question is how long a spell takes to cast, which matters when determining what sort of distraction works. "Standard" action spells are less than six seconds. Most DMs would probably let you cast Bonus faster than that, and Reaction ones even faster, even if there's no strict rule saying that that's how it works. This matters if you want to eg. stealthily cast Soul Cage during the momentary distraction caused by whatever killed your target.)

[PhantomSoul]

Needing the right pitch does, however, eliminate the possibility of whispering. You may or may not be able to do it quietly, but in order to control pitch, you actually need to vocalize it.

And resonance reinforces that it can't be whispered. (On one hand, I wouldn't assume the designers necessarily knew much of the physics/acoustics of speech production, but given the way "hums" and other vocalisations are such a cliché part of spiritual and magical effects the terms may be well-chosen, intentionally or accidentally.)

[NaughtyTiger]

ah, i was hasty in my interpretation. okay.

[Sigreid]

There's also the possibility of casting spells normally on say a crowded street where there's plenty of noise and conversations etc. going on and no one really has a reason yet to be paying attention to you. In this case it's not a matter of stealth or being quiet, it's just everyone's attending to their own business.

[Chronos]

Quoth Aquillion:

Unlike the verbal component (which makes no mention of volume), the rules emphasize that the gestures must be "forceful", which means you probably want to be Stealthed if you intend to cast without being noticed.
No, it says they might be forceful, or they might be intricate.


Quoth Lunali:

Which is why a lot of casters rely on a focus instead, much easier to hide the fact that your hand brushed against something at your belt, than that you reached into a component pouch.
You don't have to reach into a component pouch to use it. You just use the pouch itself in place of the specified components. Think of it as a medicine pouch. But yeah, a staff is easy to make look innocuous.