How does detect magic even works ?

[GâtFromKI]

So, detect magic isn't a "personal" spell, but an area spell. And in the area of a Detect magic spell, for sure there is an active Detect magic spell.

So, I cast the spell, and during the first round I get the information "there is at least one active magical effect in the area of your active magical effect". Thank you, captain obvious.

And how does the spell interact with the spell Magic aura ? Is the aura of Magic aura detected ? I mean, Magic aura can hide the aura of an object, but doesn't hide its own aura. "Hum, this sword isn't magical at all; there is only a faint illusion effect on it".

How does the spell interact with any illusion spell ? What good are illusions if they are automatically detected as such by any spellcaster ever ?

[Trekkie90909]

My rules-fu regarding the spell Magic Aura:

Magic Aura specifies that it affects "Target: one touched object weighing up to 5 lbs./level"

The description further specifies that "You alter an item's aura so that it registers to detect spells (and spells with similar capabilities) as though it were non-magical, or a magic item of a kind you specify, or the subject of a spell you specify."

Now, since you're targeting the item with magic aura, magic aura is included under its own effects, since it is now part of the item's aura, so we continue to:

"If the object bearing magic aura has identify cast on it or is similarly examined, the examiner recognizes that the aura is false and detects the object's actual qualities if he succeeds on a Will save. Otherwise, he believes the aura and no amount of testing reveals what the true magic is.

If the targeted item's own aura is exceptionally powerful (if it is an artifact, for instance), magic aura doesn't work."

So the only way to determine that magic aura has been placed on the item is to cast identify on the item, and then succeed on a will save.

Where this line of thought breaks down:

At the very end of the spell description there is the following line: "Note: A magic weapon, shield, or suit of armor must be a masterwork item, so a sword of average make, for example, looks suspicious if it has a magical aura."

Which seems out of place unless the spell detects as a magical aura regardless of its own verbiage, so YMMV.

Regarding Illusions: By strict RAW, yes detect magic would foil all magical illusions the caster can see, since they would have illusion auras. There's a little room for fudging, since the caster might only know that the illusion aura is coming from a direction, or a group of objects, rather than the specific illusionary object itself, but that seems beyond the intended scope of the cantrip to me. I personally require a will save, as otherwise the spell "true seeing" is redundant, or meta-issues arise.

[Chief Cook and Bottlewasher]

Trekkie90909 wrote:

My rules-fu regarding the spell Magic Aura:

Magic Aura specifies that it affects "Target: one touched object weighing up to 5 lbs./level"

The description further specifies that "You alter an item's aura so that it registers to detect spells (and spells with similar capabilities) as though it were non-magical, or a magic item of a kind you specify, or the subject of a spell you specify."

Now, since you're targeting the item with magic aura, magic aura is included under its own effects, since it is now part of the item's aura, so we continue to:

"If the object bearing magic aura has identify cast on it or is similarly examined, the examiner recognizes that the aura is false and detects the object's actual qualities if he succeeds on a Will save. Otherwise, he believes the aura and no amount of testing reveals what the true magic is.

If the targeted item's own aura is exceptionally powerful (if it is an artifact, for instance), magic aura doesn't work."

So the only way to determine that magic aura has been placed on the item is to cast identify on the item, and then succeed on a will save.

Where this line of thought breaks down:

At the very end of the spell description there is the following line: "Note: A magic weapon, shield, or suit of armor must be a masterwork item, so a sword of average make, for example, looks suspicious if it has a magical aura."

Which seems out of place unless the spell detects as a magical aura regardless of its own verbiage, so YMMV.

Regarding Illusions: By strict RAW, yes detect magic would foil all magical illusions the caster can see, since they would have illusion auras. There's a little room for fudging, since the caster might only know that the illusion aura is coming from a direction, or a group of objects, rather than the specific illusionary object itself, but that seems beyond the intended scope of the cantrip to me. I personally require a will save, as otherwise the spell "true seeing" is redundant, or meta-issues arise.

Smash-and-grab raids, where you might concentrate on grabbing anything with a magic aura.

A magic aura on a non-masterwork object suggests it might be a decoy. It would be prudent to check for contact poison as well.

[GâtFromKI]

Trekkie90909 wrote:

My rules-fu regarding the spell Magic Aura:

Magic Aura specifies that it affects "Target: one touched object weighing up to 5 lbs./level"

The description further specifies that "You alter an item's aura so that it registers to detect spells (and spells with similar capabilities) as though it were non-magical, or a magic item of a kind you specify, or the subject of a spell you specify."

Now, since you're targeting the item with magic aura, magic aura is included under its own effects, since it is now part of the item's aura, so we continue to:

I'm not sure about that.

I mean, if you cast a spell on an object, does the aura of the spell now belong to the object ? Is the object considered magic (may it try a Save when unattended, does an armor or a sword gain hardness and hit point if you cast Magic weapon on it) ? If the object is affected by an area spell (let's say, it is in a Silence area), do you detect that spell also as part of its aura ?

[CampinCarl9127]

I'm going to interpret the rules in such a way that magic aura (an already weak spell) is not entirely pointless. I don't believe it was the intention of the authors to write the effects of the spell in such a way that it doesn't mask itself, effectively making it useless.

[Slithery D]

Trekkie90909 wrote:

Where this line of thought breaks down:

At the very end of the spell description there is the following line: "Note: A magic weapon, shield, or suit of armor must be a masterwork item, so a sword of average make, for example, looks suspicious if it has a magical aura."

Which seems out of place unless the spell detects as a magical aura regardless of its own verbiage, so YMMV.

This part is referring to the option to give a nonmagical item a magical aura. So if you scan a mundane, nonmasterwork sword and get magic aura off it (because of this spell), you're going to wonder whether it's actually enchanted, subject to an illusion hiding its presumed masterwork quality, or what.

It's not relevant to the "hide an aura" option.

[Queen Moragan]

Casting Detect Magic on a mundane sword subjucted to a Magic Aura spell does not grant the ability to distinguish mundane from masterwork.

[Slithery D]

Basic familiarity with an item grants the ability to distinguish mundane from masterwork.

[Queen Moragan]

Slithery D wrote:

Basic familiarity with an item grants the ability to distinguish mundane from masterwork.

Proficiency with a weapon or armor should grant the ability to to distinguish mundane from masterwork. As should having the skill to craft an item or being skilled in the use of an item.

A 1st level wizard can cast Detect Magic on a bastard sword to determine if it is magical, but the same wizard should not be able to tell if it is actually masterwork quality if he can't properly use or make the thing.

[Slithery D]

I can buy that.

[Jiggy]

Queen Moragan wrote:

Slithery D wrote:

Basic familiarity with an item grants the ability to distinguish mundane from masterwork.

Proficiency with a weapon or armor should grant the ability to to distinguish mundane from masterwork. As should having the skill to craft an item or being skilled in the use of an item.

A 1st level wizard can cast Detect Magic on a bastard sword to determine if it is magical, but the same wizard should not be able to tell if it is actually masterwork quality if he can't properly use or make the thing.

Yeah, sort of like how my inability to manufacture electronics prevents me from distinguishing between my crappy flip-phone and a real smartphone. Or how the fact I'm not a professional baker means I can't tell the difference between an over-baked Betty Crocker mix with cheap frosting slathered haphazardly across it and a professional wedding cake from the specialty bakery a couple blocks away.

Hey, wait a second...

[Brain in a Jar]

If anything is going to be needed to determine masterwork quality or not wouldn't it be Appraise?

[Slithery D]

I think there's a spectrum. Some things are going to be obvious. Just like I can hear the difference between a cheap and expensive guitar untrained (my marketing class did this experiment the other day), some people can swing a normal and a masterwork sword and just feel the balance difference or see the finer edge. For some things it might be closer.

But because this is the internet we'll argue for 100 more comments about this trivial edge case on a rarely used spell.

[Paladin of Baha-who?]

Appraise would be the appropriate skill. DC 20 determines the price of an item, which will tell you if it is 300 more than a normal weapon of that type, i.e. masterwork.

[Slithery D]

I think you can tell something is masterwork/superior quality without knowing what the price is.

I can tell a diamond is twice the size and apparently similar in quality of one next to it, but that doesn't mean I know what either one is worth.

Jiggy has the right idea.

[Queen Moragan]

Jiggy wrote:

Yeah, sort of like how my inability to manufacture electronics prevents me from distinguishing between my crappy flip-phone and a real smartphone. Or how the fact I'm not a professional baker means I can't tell the difference between an over-baked Betty Crocker mix with cheap frosting slathered haphazardly across it and a professional wedding cake from the specialty bakery a couple blocks away.

Hey, wait a second...

Mundane does not mean it is of poor quality or that it is of shoddy appearance, just as masterwork does not mean it is better looking.

A superior quality item can be visually indistinguishable from its normal counterpart.

We are after all talking about using Magic Aura to create a fake magic item, such a fake magic item does not need to fool everyone all of the time.

[Christopher Dudley]

Queen Moragan wrote:

Mundane does not mean it is of poor quality or that it is of shoddy appearance, just as masterwork does not mean it is better looking.

While I think you raise a good point, it never occurred to me not to divulge an item's quality, and it is an easy handwave for me. I think in general masterwork items DO look better. I draw this from the trope of the fantasy hero who forges his weapon to defeat the BBEG. It always looks better. So, while I hate to be the one saying "But there's dragons!" but I always felt the ability to distinguish a masterwork item is implicit in the genre. There are a few "everyman" abilities that you can just smile and accept to make the fantasy world relatable. Like literacy, and the fact that "barbarian" is just a job title, and tells you nothing about the person's land of origin. Eyeballing masterwork weapons? Sure, why not.

[Berinor]

There are magic items that deliberately look shoddy. Or, more often, rough. They'll still be of masterwork quality, but that difference makes it hard to draw absolute conclusions. Suspicion, sure.

[Crimeo]

re magic aura:

Quote:

You alter an item's aura so that it registers to detect spells (and spells with similar capabilities) as though it were non-magical

This necessarily requires that magic aura masks its own aura as well, otherwise this sentence would not be true, since the item would register as faint illusion, not as "non-magical". This one I think is unambiguously not a problem, due to the spell's text.

re detect magic and itself:
Obviously this is not intended, and you probably shouldn't play at your table that way because it's dumb, but technically by RAW, I think it would always detect a magical presence due to itself, yes. Interestingly, this makes your last question less of an issue if you actually play that way versus re-ruling it:

re illusions:
Yes, detect magic will detect an illusion. This does not actually end up mattering that much, because constantly detecting magic every 10 steps you take

1) Means you're always announcing your presence as a wizard way ahead of yourself and rousing every arrow from every bandit and so on,

2) Means you're walking at like 1/2 or slower speed. Especially if you rule that detect magic detects itself (as above), because then you'd have to wait until round two to know anything is amiss, and so that's 3 actions burned (initial plus full round cycle) standing still, for every 2 move actions moving forward even at a dash. (slower if in a wider hallway, since less of your 60ft cone reaches both walls, you could be down to 1/4 or slower speed!) You're never going to catch anybody that way, anybody hiding with an illusion to buy their friend's escape can easily do so anyway, etc., and

3) Means you must already have some reason to suspect illusions, and if that were the case, wouldn't it be more efficient anyway to just run your hands along all the walls or spread out and run over every hillock as you jog by?

[Ring_of_Gyges]

Fun fact: The mythic Invisibility spell specifies that the target is not detected by Detect Magic, which means that the standard non-mythic Invisibility spell's target *is*.

That's one point in favor of the "Detect Magic hoses all sorts of illusions" theory.

To be fair, Detect Magic isn't a replacement for See Invisibility. It takes several rounds and standard actions. On round 1 you just know there is magic in the cone you're projecting. On round 2 you know there is one faint aura. On round 3 you know there is an illusion effect and what square it is in, but don't know what specific spell. That should be plenty of time for an invisible opponent to get out of your 60ft cone.

It's still not a very satisfying result for many people, house rule at your pleasure...

[GâtFromKI]

Ring_of_Gyges wrote:

To be fair, Detect Magic isn't a replacement for See Invisibility. It takes several rounds and standard actions. On round 1 you just know there is magic in the cone you're projecting. On round 2 you know there is one faint aura. On round 3 you know there is an illusion effect and what square it is in, but don't know what specific spell. That should be plenty of time for an invisible opponent to get out of your 60ft cone.

Actually Detect magic should detect its own area, since it is a magical effect present in its area. So round 1 it detects the presence of magic, and round 2 it detects two faint auras. Round 3 it can find the school of anything that is in line of sight, but is an invisible creature actually in line of sight ? So it detects a faint divination aura, and another faint aura that may or may not be identified as illusion.

I'm not sure how the spell works.

[CBDunkerson]

What is the practical difference between 'Detect Magic' being able to detect itself vs not being able to do so? The caster might have forgotten that he cast the spell?

Crimeo answered the other questions; Magic Aura hides itself and illusions are usually detectable.

So what's left to be "not sure" about? Whether detect Magic detects itself? Why does this MATTER? If it doesn't... pick a solution at random. Or ignore it until some situation where it is actually relevant to anything comes up.

[Crimeo]

Quote:

What is the practical difference between 'Detect Magic' being able to detect itself vs not being able to do so?

It makes the first round always useless, because 100% of the time it would respond "magic present" if so, thus you wouldn't get any useful info at all until round 2. Whereas in people's normal interpretation/play, they would say no other magical effects other than it is "none present" on round 1, and you can move on more quickly.

This matters a lot. In combat I often have people detecting just to see if there are zones of silence, etc. Or rather, pre-combat, I guess. But the time starts ticking once you start announcing yourself with verbal components. Wasting an extra round to get your info means another whole round of buffs for defenders, for example, before they know there's a trap.

Or if you're detecting every inch of a mile long tunnel, you're now moving 3x slower than normal, instead of 2x.

[Ring_of_Gyges]

GâtFromKI wrote:

is an invisible creature actually in line of sight?

Alas, line of sight is not a defined term. Personally, I run it like the line of effect rules, if you can draw an unobstructed line from your square to the target, you have line of sight to the target.

Alternately, the invisible character *must* be in line of sight because it is visible to someone using Detect Magic. We know the aura of an invisible creature is visible to Detect Magic because Mythic Invisibility tells us so.

Ultimately fine grained parsing of the rules is not a profitable activity. There *isn't* a right answer, the rule set is ambiguous and (has always) relied on interpretation and judgment from the GM. For example, line of sight doesn't get a definition despite being a term used mechanically in the rules. There are no objective facts to discover about how Detect Magic works because Detect Magic is make-believe. The better question is how *should* Detect Magic work to get the best game (where "best game" is a function of the tastes of your particular players).

Personally I kind of like the slow scan of Detect Magic users trying to pin down invisible opponents. Detect Magic detecting losing utility by detecting itself rubs me the wrong way. These aren't factual questions, or even rule understanding questions, they're aesthetic questions about what sort of game you'd prefer. The rule set just isn't rigorous enough to answer questions at this level of detail, any answer will be invention, so invent something aesthetically pleasing given your gaming preferences.