How does Detect Magic work?

[Darth Ultron]

So how does detect magic work anyway.....the spell write up is so unclear...

Ok, Zora casts detect magic and looks at a room full of people.
Round 1-So this is a ''yes/no'' right? She'd get a ''yes, there is at least one magic aura with in the 60 foot cone''
Round 2-So now she'd know the number of auras and the one that was strongest. But not the locations of the auras right? This is just ''13 auras in the cone, and one is strong''. Right?
Round 3-So now she knows the strength of each aura and it's location. How vague is the location? So is this ''weak aura ten feet to your left'' or is it ''the gold ring on the human ten feet to your left has a weak aura''? How pin point is it?

I've always had magic items ''glow'' when this spell is cast.....but there is nothing about glowing items in the spell description.


Related questions:
1: A magic item in a pile of like-but-not-magic items.
For example, a magic ring in a pile of rings. Under the spell, is the caster able to pick out the exact ring that is magical, or will he just know that something in the pile is magic?

2: A magic item in a container
For example, a magic ring in a cloth bag, wood chest, or wooden drawer. Will the caster be able to detect that something magic is contained within, or would he need to open the container and look within to see the magic aura? (1" thick iron chest clearly by the text would block the magic aura) Does detect magic have to be line of sight?

3: A magic item with passive power on a person
For example, a ring of protection or ring of fire resistance, being worn. Does the magic item give off an aura (you can see they have a magic ring) or does the characters whole body radiate magic (you can see there is a magic effect on our about their persons)?

4: A magic item with activated/non-user-affecting power on a person
For example, a ring of wishes or necklace of fireballs worn by a character. Can the viewer see that the ring/necklace is magic, or just that something about the person is magic?

[Flickerdart]

In absence of clarification, "location" can be your "glow" on magic items just as easily as anything else, since it would accomplish the literal goal of showing you where the item is and not showing you where it is not.

Detect Magic does not require line of sight/effect, and I'd say that it does tell you they are carrying a magic item (as opposed to a spell effect on them, which would show them glowing).

[endur]

1: A magic item in a pile of like-but-not-magic items.
For example, a magic ring in a pile of rings. Under the spell, is the caster able to pick out the exact ring that is magical, or will he just know that something in the pile is magic?


Both. If he has Line of Sight to the magical ring, he can pick it out. If the magical ring is buried under the pile, he just knows it is in the pile.



2: A magic item in a container
For example, a magic ring in a cloth bag, wood chest, or wooden drawer. Will the caster be able to detect that something magic is contained within, or would he need to open the container and look within to see the magic aura? (1" thick iron chest clearly by the text would block the magic aura) Does detect magic have to be line of sight?


He knows that something magic is within the container. The spell description tells you when line of sight matters.



3: A magic item with passive power on a person
For example, a ring of protection or ring of fire resistance, being worn. Does the magic item give off an aura (you can see they have a magic ring) or does the characters whole body radiate magic (you can see there is a magic effect on our about their persons)?


Both, sort of. The ring is detected as a magical item. The effect on the character's body is detected as a functioning spell. Detect Magic will reveal the stronger aura of the two.



4: A magic item with activated/non-user-affecting power on a person
For example, a ring of wishes or necklace of fireballs worn by a character. Can the viewer see that the ring/necklace is magic, or just that something about the person is magic?

The ring/necklace is detected as a magical item if you can see it. If you can't see it (glove on the hand covering the ring), then its not clear how precise your information is on where the magical item is located.

[Darth Ultron]

In absence of clarification, "location" can be your "glow" on magic items just as easily as anything else, since it would accomplish the literal goal of showing you where the item is and not showing you where it is not.

This brings up one of the problems in my game though: Do you see the glow through an object. If a magic ring is in a chest, will you see a glowing aura come out of the chest?

[Flickerdart]

This brings up one of the problems in my game though: Do you see the glow through an object. If a magic ring is in a chest, will you see a glowing aura come out of the chest?
Nothing about Detect Magic refers to sight. Unless the object is thick enough to block the spell, you perceive the location of the magic.

[Psyren]

This brings up one of the problems in my game though: Do you see the glow through an object. If a magic ring is in a chest, will you see a glowing aura come out of the chest?

Yes, unless the chest is lined with lead etc.

[Roncorps]

I think of it more like a echolocation, or maybe like the earthbender earth-detection-searching-ability. Maybe like a doppler radar (technology based on echolocation). A magiecholocation. Magic item bounce back to you, not in a sight manner, but as a radar manner. Each round, you analyse more and more the ''signals'' and can pinpoint with a good accuracy where it is/they are and his/their strength.

That's my way of explaning it.

"Return in his submarine"

[Curmudgeon]

Nothing about Detect Magic refers to sight. Unless the object is thick enough to block the spell, you perceive the location of the magic.
I beg to differ.

3rd Round
The strength and location of each aura. If the items or creatures bearing the auras are in line of sight, you can make Spellcraft skill checks to determine the school of magic involved in each.
Location, in D&D, means 5' squares. If there's a magic item on a creature, you detect a magical aura in that location. You don't know if it's the creature, the item, or a spell effect in the area: you're detecting auras, not precise sources. A successful Spellcraft check may give you some additional information to narrow down the list of possibilities.

[Deophaun]

Location, in D&D, means 5' squares.
Citation needed, because if true, this means miss chance doesn't do anything if someone knows what square you're in:

miss chance: The possibility that a successful attack roll misses anyway because of the attacker’s uncertainty about the target’s location. See concealment.
And we're dealing with really big druids:

Any gear worn or carried by the druid melds into the new form and becomes nonfunctional. When the druid reverts to her true form, any objects previously melded into the new form reappear in the same location on her body that they previously occupied and are once again functional. Any new items worn in the assumed form fall off and land at the druid's feet.

[Ashtagon]

I normally fluff detect magic as allowing you to see what Warhammer calls the aether and Pratchett calls octarine. Basically, every magical thing "glows" distinctively. This glow can be seen through other objects as well, albeit somewhat muted. The shape, colour, and pattern of swirls gives experienced users clues as to what kind of object it is and what kind of magic it possesses. Three feet of solid material, or thinner amounts of certain 'harder' materials, blocks the aura.

Vaguely related:
https://en.wikipedia.org/wiki/Kirlian_photography

[Curmudgeon]

Citation needed, because if true, this means miss chance doesn't do anything if someone knows what square you're in
That's not true. Everything you need is in the description of invisibility (http://www.d20srd.org/srd/specialAbilities.htm#invisibility) (Dungeon Master's Guide, page 295). The two most relevant citations:
It’s practically impossible to pinpoint the location of an invisible creature. A Listen check that beats the DC by 20 pinpoints the invisible creature’s location.
...
If a character tries to attack an invisible creature whose location he has pinpointed, he attacks normally, but the invisible creature still benefits from full concealment (and thus a 50% miss chance). The smallest ("pinpoint") specification of a location is the square. There's no location smaller than that in the game.
Total Concealment
If you have line of effect to a target but not line of sight he is considered to have total concealment from you. You can’t attack an opponent that has total concealment, though you can attack into a square that you think he occupies. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of the normal 20% miss chance for an opponent with concealment). You don't (can't) attack into the northeast corner of a square; you attack into the entire square.

[Deophaun]

That's not true.
It is true, because if there is no uncertainty about the square, then there is no miss chance. The PHB says so, according to you. Invisibility and Total Concealment may be more specific examples, but everything that simply refers to concealment (like the child of shadow stance from ToB, or even darkness) is defeated by simply knowing the square if your horribly mistaken interpretation was anywhere close to reality.

The two most relevant citations: The smallest ("pinpoint") specification of a location is the square. There's no location smaller than that in the game.
So, you are stating that druids are all at least Large sized creatures.

You're cherry picking examples in order to fabricate game terminology where game terminology does not exist.

[defiantdan]

Think about it though the square is the smallest unit of measurement. Creatures smaller than medium still only occupy 5x5 squares (the rules just say you can fit more of them into that square). Targeting a pixie is first picking the right square then dealing with it's total concealment (invisibility). you don't target one half of the square or the other. It's a procedure. step one is always picking the correct square. step 2 determine if it has concealment. step three role appropriate dice to determine a hit. ect.

[Deophaun]

Think about it though the square is the smallest unit of measurement.
It's not. Look at the rules for Jump, or even look at the height section of your character sheet. Look at stone shape. There are plenty of areas where there are smaller units of measurement.

Besides that, your post completely misses the point. Crumudgeon insists that "location" has only ever referred to 5' squares, even when there are two quotes from the PHB and SRD right in front of him saying otherwise.

[defiantdan]

but it all ties in. There are two forms of measurement in D&D. Narrative and Tactical. they mention it in movement but it easily applies to pretty much all measurement in D&D. The world when measured tactically is 5x5x5 squares. I can't take a 1ft step on the game board. I can take a 1ft step in the narrative world. So the rules of a pin point location really do come down to a square location. if it was all narrative then it really doesn't matter.

[Smorgonoffz]

What happens if someone casts detect magic, while someone in the same room is invisible thanks to a magic item?

[Deophaun]

So the rules of a pin point location really do come down to a square location.
Again, you're missing the entire point.

What Curmudgeon has done is mistake "pinpoint," which is actually defined by the game, for "location," which isn't. Where does the word "pinpoint" appear in the text for detect magic? No where. So any rules related to pinpointing an object have no bearing on the spell.

Meanwhile, Crumudgeon leaves us with 5' squares within 5' squares. It's Squareception!

Place a dot in the center of each square that you decide has a tree in it, and don’t worry about the tree’s exact location within the square.
Prayer beads that most graciously do not have to be in their special 5' square in order to work

The owner need not hold or wear the strand of prayer beads in any specific location, as long as he carries it somewhere on his person.
And pixies that can host a battle between 11 Medium sized creatures.


Location Damage Affects:
Hand Climb, Craft, Disable Device, Escape Artist, Forgery, Heal, Open Lock, Sleight of Hand, and Use Rope checks; attack rolls.
Arm Climb and Swim checks; attack rolls; Strength checks.
Head All attack rolls, saves, and checks.
One eye Appraise, Craft, Decipher Script, Disable Device, Forgery, Open Lock, Search, Sense Motive, Spellcraft, and Spot checks; Survival checks (for tracking); initiative checks; Dexterity checks; ranged attack rolls; Reflex saving throws. Severe damage to both eyes causes a character to become blinded.
One ear Listen checks; initiative checks. Severe damage to both ears causes a character to become deafened.
Foot/Leg Balance, Climb, Jump, Move Silently, Ride, Swim, and Tumble checks; Reflex saving throws; Dexterity checks.


Edit: And if you think the difference between "There's a strong abjuration aura in the square 5' north of you" and "The cleric's amulet emits a strong abjuration aura" is simply the difference between tactical and narrative measurement, you've never played a caster with dispel magic.

[Flickerdart]

I beg to differ.
That part isn't even talking about locating, merely Spellcraft checks.


Crumudgeon
Crumbdungeon.

Benedict Crumberbatch.

[Darth Ultron]

Location, in D&D, means 5' squares

Is this right? This is the core of the problem. What kind of ''location'' does Detect Magic give?

A wizard puts a gold ring and a sliver ring on a table and casts detect magic. So on the third round does the wizard know the location of the aura is the sliver ring? Or is it more ''the aura is on the table'' or even ''it's two feet in front of you''? Do you need to look at each ring one at a time and get a magic or no magic detection?

When a wizard looks at a person, can they on the third round see the aura coming form individual items and discover the person has magic boots and a magic hat? Or do they just get ''two auras five feet to your left''.

[Curmudgeon]

It is true, because if there is no uncertainty about the square, then there is no miss chance.
I just quoted the part which says otherwise. Total concealment is the game term used when you're required to attack into the square as a whole because you can't see the creature in that square. Your arrow can't physically hit the whole square, so there's obviously a miss chance. There is no smaller location possible, though. That is, there is no mechanism to determine a creature's location to be some particular part of a square, or to send your arrow into the northeast corner of that square; you can only attack into the square (location) as a whole if you can't see the creature in it.

So, you are stating that druids are all at least Large sized creatures.
I have no idea what you're going on about there.

[Deophaun]

I just quoted the part which says otherwise. Total concealment ...
...is not concealment.

I have no idea what you're going on about there.
Because you have to be at least Large to have a 5' square on you, don't you?

Ah wait, no. I already established pixies have 11 5' squares on them.

[Curmudgeon]

...is not concealment.
Again, I have no idea what you're going on about. Concealment of any type gives a miss chance, but normal concealment has nothing to do with the creature's location (square) being unknown.

[Deophaun]

Again, I have no idea what you're going on about. Concealment of any type gives a miss chance, but normal concealment has nothing to do with the creature's location (square) being unknown.
That's what miss chance is. I quoted it.

I have provided FIVE quotes from core where location is NOT used to refer to a 5' square. You are wrong.

[Curmudgeon]

I have provided FIVE quotes from core where location is NOT used to refer to a 5' square. You are wrong.
Even precise definitions of D&D terminology don't mean those words are always used precisely. You've just found some examples of such imprecise use. To illustrate the point, a Glossary definition (http://archive.wizards.com/default.asp?x=dnd/glossary&term=Glossary_dnd_bonus&alpha=B):
bonus

A positive modifier to a die roll. However, the word "bonus" is also used colloquially in the ordinary dictionary sense of "extra" or "free". The Monk Bonus Feat (http://www.d20srd.org/srd/classes/monk.htm#bonusFeat) class feature is not specific to feats which grant a positive modifier to a die roll. Your five quotes illustrate informal use of language, but have no rules meaning. Location, when not used colloquially, refers to 5' squares.

[Deophaun]

Location, when not used colloquially, refers to 5' squares.
And no true scotsman would argue otherwise.

You will notice, Curmudgeon, that this is no glossary definition for "location." You definition is an invention of your mind, not part of the rules.

[Darth Ultron]

I have provided FIVE quotes from core where location is NOT used to refer to a 5' square.

So what does ''location'' mean to Detect Magic?

[Duke of Urrel]

So what does ''location'' mean to Detect Magic?

As Curmudgeon and Deophaun have demonstrated, there is more than one way to interpret the word "location."

If you interpret the word "location" as Curmudgeon does, the questions you asked at the start of this thread can all be answered – negatively. No, if a magic ring is mixed with other rings in a pile, the Detect Magic spell doesn't empower you to see which ring is magical. No, if your enemy is wearing a Ring of Bull's Strength, the Detect Magic spell doesn't empower you to see that your enemy's strength comes from the ring he is wearing. And so on … because the magic aura that you can see has a "location" no more specific than the five-foot square (or squares) that it occupies.

If you interpret the word "location" as Deophaun does, then the answer to your original questions is mostly "maybe." I think we need house rules to determine exactly how accurate the Detect Magic spell is if its accuracy is greater than Curmudgeon would allow.

I have devised many house rules of my own merely in order to describe the appearance of magic auras – once you become able to see them. For example, I consider visible magic auras to be roughly spherical, although they take the approximate shape of any creature or portable object that "carries" the effect of a spell. A magic aura that represents an immobile spell is usually centered around a point, a line, or a plane, so that it may have a cylindrical or sandwich-like shape rather than a spherical one. The radius of a magic aura indicates the strength of the magic that it represents, so that a "dim" magic aura has a radius of 2 inches, a "faint" aura a radius of 4 inches, a "moderate" aura a radius of 6 inches, and so on. A magic aura can shine through any solid object that is not made of lead, a very thick piece of some metal other than lead, or an even thicker piece of some other material. Every school of magic is represented by a magic aura of a different color. I consider a magic aura to look like a glowing jellyfish, having a border that is a little brighter than its center. I don't allow a magic aura to illuminate anything besides itself, but if you can see a magic aura, I add -4 to the Spot DC of anything that carries the aura. (This is the same as the visible effect of two Abjuration spells active in proximity for 24 hours or more, which creates flickering magic auras that anybody can see.) On the other hand, the invisible carrier of a magic aura does not become visible; if it is an invisible creature, your attacks against it still suffer a 50% miss chance, though seeing the aura enables you to pinpoint the creature's location.

These are all house rules, and I have many others besides. For example, I have a house rule that the Detect Magic spell can detect only one spell if several perfectly overlapping spells have been cast upon the same object or creature – this is always the spell whose level is higher or that has been cast more recently.

So in conclusion, if you're the dungeon master, you have some decisions to make. If you're a player, you need to have a talk with your dungeon master about how he or she interprets the Detect Magic spell.

[Deophaun]

So what does ''location'' mean to Detect Magic?
Location means enough so you don't have to stop playing the game for the players to figure out how to process the contents of a room, and then repeat that after every single encounter.

[FocusWolf413]

As Curmudgeon and Deophaun have demonstrated, there is more than one way to interpret the word "location."

If you interpret the word "location" as Curmudgeon does, the questions you asked at the start of this thread can all be answered – negatively. No, if a magic ring is mixed with other rings in a pile, the Detect Magic spell doesn't empower you to see which ring is magical. No, if your enemy is wearing a Ring of Bull's Strength, the Detect Magic spell doesn't empower you to see that your enemy's strength comes from the ring he is wearing. And so on … because the magic aura that you can see has a "location" no more specific than the five-foot square (or squares) that it occupies.

If you interpret the word "location" as Deophaun does, then the answer to your original questions is mostly "maybe." I think we need house rules to determine exactly how accurate the Detect Magic spell is if its accuracy is greater than Curmudgeon would allow.

I have devised many house rules of my own merely in order to describe the appearance of magic auras – once you become able to see them. For example, I consider visible magic auras to be roughly spherical, although they take the approximate shape of any creature or portable object that "carries" the effect of a spell. A magic aura that represents an immobile spell is usually centered around a point, a line, or a plane, so that it may have a cylindrical or sandwich-like shape rather than a spherical one. The radius of a magic aura indicates the strength of the magic that it represents, so that a "dim" magic aura has a radius of 2 inches, a "faint" aura a radius of 4 inches, a "moderate" aura a radius of 6 inches, and so on. A magic aura can shine through any solid object that is not made of lead, a very thick piece of some metal other than lead, or an even thicker piece of some other material. Every school of magic is represented by a magic aura of a different color. I consider a magic aura to look like a glowing jellyfish, having a border that is a little brighter than its center. I don't allow a magic aura to illuminate anything besides itself, but if you can see a magic aura, I add -4 to the Spot DC of anything that carries the aura. (This is the same as the visible effect of two Abjuration spells active in proximity for 24 hours or more, which creates flickering magic auras that anybody can see.) On the other hand, the invisible carrier of a magic aura does not become visible; if it is an invisible creature, your attacks against it still suffer a 50% miss chance, though seeing the aura enables you to pinpoint the creature's location.

These are all house rules, and I have many others besides. For example, I have a house rule that the Detect Magic spell can detect only one spell if several perfectly overlapping spells have been cast upon the same object or creature – this is always the spell whose level is higher or that has been cast more recently.

So in conclusion, if you're the dungeon master, you have some decisions to make. If you're a player, you need to have a talk with your dungeon master about how he or she interprets the Detect Magic spell.



I generally agree with these hourhouserules. One I would change is the only detecting the top overlapping spell aura. I would say something like "you detect some weaker magic auras, but they are drowned out by the top one" or something like that.