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View Full Version : Do you allow your casters to use detect magic to see invisible creatures?



Eclipse
2008-12-05, 12:33 AM
Now, I know by RAW detect magic (http://www.d20srd.org/srd/spells/detectMagic.htm) can locate invisible creatures, since it reveals magical auras for any magical effects within range. That's not what I'm posting this to debate or gain opinions on. Rather, I'm more interested in if you allow or don't allow this for whatever reason you may have.

Personally, I don't allow it to be used in this fashion. I think that it can be used in this fashion was an oversight, and it was intended that you not be able to defeat the spell invisibility without using at least the second level spell see invisibility. Detect magic is already quite good for a 0th level spell, and adding even more versatility to it seems to be out of line with what most 0th level spells do.

That said, I can certainly see many arguments to allow it as well. Detect magic is a cone shaped emanation with a 60 ft. range, while see invisibility allows the caster to see anyone invisible within his range of vision. As such, detect magic is still a poor substitute for see invisibility, but it will do in a pinch. In addition, there are other very versatile 0th level spells, such as create water and prestidigitation, so there is precedent for a few spells of 0th level being quite useful. Perhaps detect magic really does fall in with this crowd.

So, with that said, how do you handle it in your games? Has it ever even come up?

Ponce
2008-12-05, 12:40 AM
If the invisible object/creature is stationary, OK. If it is moving/running/fighting, then no I usually don't allow it.

NEO|Phyte
2008-12-05, 12:40 AM
If an invisible creature lets the wizard take three rounds of concentrating on a spell to locate its square, it deserves to be located.

Eclipse
2008-12-05, 01:48 AM
If an invisible creature lets the wizard take three rounds of concentrating on a spell to locate its square, it deserves to be located.

While I see what you're saying, it could be the party is actually defending the wizard during this time. Not that that's a good excuse, but it can be done effectively sometimes, even against an invisible creature.

Then again, I guess if the party pulls that off, you are right in that they deserve to be located. Perhaps I just shouldn't bother house ruling that anymore, given the time it takes.

Kizara
2008-12-05, 01:59 AM
While I see what you're saying, it could be the party is actually defending the wizard during this time. Not that that's a good excuse, but it can be done effectively sometimes, even against an invisible creature.

Then again, I guess if the party pulls that off, you are right in that they deserve to be located. Perhaps I just shouldn't bother house ruling that anymore, given the time it takes.

Run it exactly as it is written. It is perfectly logical, balanced use of the spell that allows you to know the location of an magically invisible creature after 3 rounds of concentration for that round only (then it presumably moves). Want to know what spell is overpowered and needs adjusting? Glitterdust.

If you want a creature to defend against this, simply use an ability that would block low-level divination (options are plentiful).

Mewtarthio
2008-12-05, 02:03 AM
The Wizard not only needs to concentrate for three rounds, he also needs to keep the invisible creature within the cone for the entire time. In the end, he still only sees the aura, not the creature itself. He can attack the location, but that's still a 50% miss chance (and it breaks concentration, too). At most, he'll be able to let everyone else know where the invisible creature is and have them attack it blind until it leaves the cone.

monty
2008-12-05, 02:06 AM
It takes three rounds, and they still have total concealment. Not unbalanced at all.

Tacoma
2008-12-05, 02:06 AM
I'm more used to 1st and 2nd edition. But here goes:

Detect magic is typically carried because it's a general-use spell. There's always loot to sort. Because of this, I like to limit it's effectiveness for a couple reasons: See Invisibility and Find Traps.

See, if players could detect magical traps using Detect Magic, that defeats the purpose of Find Traps. So I ruled that magical traps are specifically designed to evade that single low level spell. Seems reasonable enough. Kind of like how Shield specifically wards off Magic Missile.

Second, See Invisibility is a 2nd level spell with a very specific use. And nobody ever memorizes it even when Detect Magic doesn't detect invisible objects. So guess how often it gets used when Detect Magic can find invisible things?

Furthermore, Detect Magic cannot tell if an item is cursed. It doesn't detect the aura of a charmed or geased person. Detect Charm is meant to find charms specifically, and a geas is so powerful only a spell of similar power should be able to see it. And Detect Magic cannot tell that an illusion is magical. There is a spell for seeing illusions.

Even without these functions a Detect Magic is still quite useful. For example:

1: Find what treasure in a hoard is magical.
2: Note which items on an enemy are magical.
3: Note which enemies have magical buffs of some kind.
4: See that the wall next to you is magical (and is probably a Wall of Stone).
5: Tell whether the magic item you're about to buy is even magical.
6: Oh look, a guy is hiding in the shadows over there wearing magic leather armor and holding a magic sword covered in nonmagical goop. Light!

Basically it's a really useful and indispensable cantrip. But the only way a lower level spell trumps a higher level spell is when the lower spell is specifically built to trump the higher one, the higher one is more general in nature than the lower one, and the level difference is very small.

EDIT: But forget that "3 rounds concentration" garbage. You cast it and now you see auras within 60 feet until the duration is up. I like a spell to be actually usable but narrowly defined rather than a catchall that you can never use because it must be Monday the 12th and the moon must be in the east.

Khanderas
2008-12-05, 02:09 AM
Several good arguments for it not being overpowered above. Sure, I agree.
But I personally agree with the OP, on this being an oversight and I would not let players use detect magic as an optional way to see invisibility.
Well kinda see invisibility.

BobVosh
2008-12-05, 02:21 AM
I think detect magic is extremely well thought out, espically as far as spells go.

Who memorizes see invisible, when they have glitterdust?

Keld Denar
2008-12-05, 02:28 AM
Who memorizes see invisible, when they have glitterdust?

Because See Invis has a long duration, can be extended easily via Lesser Rod, and recalled cheaply via Pearl of Power2 for chump change at mid-high levels.

And cause See Invis allows you to actually see an invisible creature coming so you can light it up (Glitterdust) for the rest of your party to see, rather than react because someone discovered a short sword protruding from their squishy bits.

And cause sometimes you know about where the foe is, and don't want to be firing off somewhat limited spells that may potentially hit your allies as well if the target is between a couple of them.

And cause See Invis allows you to see into the Ethereal Plane, a place typically only you can affect with [Force] spells, and where Glitterdust cast on the Prime has no effect?

Weiser_Cain
2008-12-05, 02:32 AM
only if they're invisible via magic and not say, clear. I also do a novel-y thing and let a high spot or listen roll trigger the spell's effect.

Tacoma
2008-12-05, 02:43 AM
This intrigues me. I had always known of the three standard types of invisibility:

1: Light bends around him via illusion.

2: The covered object is blocked from the target's mind, so it includes all senses.

3: The covered object has coloration exactly like what is behind him from the perspective of every observer.

But lo!

4: The covered object is clear and light passes through.

Good gravy, my mind hath been blown.

Of course one could argue that if you weren't made of molecules then you'd be invisible. I'd call that "out of phase" or "ethereal" in the sense that you can't backstab.

Kantolin
2008-12-05, 03:01 AM
1: Find what treasure in a hoard is magical.
2: Note which items on an enemy are magical.
5: Tell whether the magic item you're about to buy is even magical.

All three of those are 'detect magic items', and are really only one thing. And... and eh? I suppose at best, that tells you which items to hand to the merchant to identify?


3: Note which enemies have magical buffs of some kind.

On round one, the wizard is told: Yes
On round two that nobody went and moved or interacted with said wizard, the wizard is told '8, on the enemy creatures.'
On round three, 'Faint Abjuration. Faint Abjuration. Faint Abjuration. Faint Transmutation. Strong Transmutation. Moderate Abjuration. Faint Evocation. Faint illusion.'

Eh? I suppose that's vaguely useful information. Certianly not very helpful if you're in a fight, especially given that's three solid rounds of a party member doing absolutely nothing but trying to foil the target's invisibility should they not go behind him. Especially given that the guy who is radiating fire that freezes the fighter every time the fighter smacks him is, indeed, probably protected by a Fire Shield.


4: See that the wall next to you is magical (and is probably a Wall of Stone).

That's actually a little creative. Flaw comes that, unless the person in question is using detect magic on every wall he comes across, the one minute/level and concentration requirement makes that limiting - especially since there are only six or four attempts at it per day. Permanency can be used, but I've noted that permanency just makes you an even prettier target to dispel magic.

(Also, it wouldn't work with wall of stone, as that's instantaneous and thus would be nonmagical after it's formed. That said, it would work on illusionary walls, which would then fulfill your point).


6: Oh look, a guy is hiding in the shadows over there wearing magic leather armor and holding a magic sword covered in nonmagical goop. Light!

Why would you detect magic into that corner over there?

And what's worse, is the wizard leading the party? As if there's anyone else in his radius, he would simply get a 'yes' from them. Unless the party walks thirty feet, waits 18 seconds, walks 30 feet, waits 18 seconds, and repeats this until the spell duration runs out. Or uses a wand of detect magic or something kinda silly like that.

So meh. Detect magic is overall kind of meh. And if you ask me, invisibility (And it's elder cousin greater invisibility) is entirely too powerful as it is, so having something that has a chance after two rounds to do /something/ to stop it is useful.

Greg
2008-12-05, 03:33 AM
If an invisible creature lets the wizard take three rounds of concentrating on a spell to locate its square, it deserves to be located.
It can be permanancied though.

Sstoopidtallkid
2008-12-05, 03:34 AM
It can be permanancied though.Still requires concentration to use.

Zen Master
2008-12-05, 03:49 AM
If an invisible creature lets the wizard take three rounds of concentrating on a spell to locate its square, it deserves to be located.

Even after three rounds, it could be any spell in the illusion school. Doesn't have to be invisibility. And since you have to specify and area, you could move out of it before round three, and foil it.

By my reckoning, detect magic cannot detect invisibility - not in any practical sense.

Kantolin
2008-12-05, 04:00 AM
Still requires concentration to use.

And just begs for a dispel magic. Blam, experience gone.

Not to mention, that's basically stating you can use a 5th level spell to (pseudo) defeat invisibility. Without spending the additional experience to make it permanent see invisibility, or permanent arcane sight.

Caeldrim
2008-12-05, 04:21 AM
If someone wants to use a 'spell that isn't see invisibility' to see invisible creatures, they should be using locate object or arcane sight, which are the same level as see invisibility, so... yeah.

My DM sent me blind not so long ago (kind of different but not) and rather than sit out the fight feeling useless, these two spells restored me to very nearly complete capacity - at least, against those of my enemies who were wearing magical items/affected by magic, which in this case was all of them.

Detect Magic isn't Arcane Sight, and Arcane Sight is clearly written so you CAN use it in this way.

I'd allow the caster to try, then either:

a) have him fail when the invisible creature moved out of the cone in the first couple of rounds of concentration (if invisibled creature is smart and knows what the caster is trying to do)

or

b) have him succeed (if invisibled creature isn't moving for some reason), then realise he's lost track of the creature as soon as he breaks concentration to cast or tell his allies where the enemy is.

Basically it's an awful tactic that's not going to get anyone very far.

BobVosh
2008-12-05, 04:48 AM
Because See Invis has a long duration, can be extended easily via Lesser Rod, and recalled cheaply via Pearl of Power2 for chump change at mid-high levels.

And cause See Invis allows you to actually see an invisible creature coming so you can light it up (Glitterdust) for the rest of your party to see, rather than react because someone discovered a short sword protruding from their squishy bits.

And cause sometimes you know about where the foe is, and don't want to be firing off somewhat limited spells that may potentially hit your allies as well if the target is between a couple of them.

And cause See Invis allows you to see into the Ethereal Plane, a place typically only you can affect with [Force] spells, and where Glitterdust cast on the Prime has no effect?

Ya, you are right. I was thinking the other way around. Wand of glitterdust + memorized See Invisible

Curmudgeon
2008-12-05, 05:10 AM
1: Find what treasure in a hoard is magical. Yes, after you shovel the pile of copper pieces off.
The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.

2: Note which items on an enemy are magical.
3: Note which enemies have magical buffs of some kind. If you care at all about being stealthy, you'll buy a wand of Nystul's Magic Aura and hit all your magical gear:
You alter an itemís aura so that it registers to detect spells (and spells with similar capabilities) as though it were nonmagical, or a magic item of a kind you specify, or the subject of a spell you specify.

5: Tell whether the magic item you're about to buy is even magical. Oops! Nystul's Magic Aura can also spoof that.
You alter an itemís aura so that it registers to detect spells (and spells with similar capabilities) as though it were nonmagical, or a magic item of a kind you specify, or the subject of a spell you specify.

6: Oh look, a guy is hiding in the shadows over there wearing magic leather armor and holding a magic sword covered in nonmagical goop. Again, Nystul's Magic Aura. If the guy hiding in shadows doesn't hide his magic, too, he deserves to be noticed. Why do you think Rogues and Assassins have Use Magic Device as class skills?

Oslecamo
2008-12-05, 06:17 AM
Why do you think Rogues and Assassins have Use Magic Device as class skills?

To pick pocket the caster's wands and scrolls and use them against their owners of course:smallbiggrin:

ForzaFiori
2008-12-05, 06:39 AM
personally, I think that if the caster manages to keep an invisible person in that cone for 3 rounds, why the heck should he NOT be able to tell? Not to mention that not allowing it is just kinda weird. "This spell can detect all magic. Except traps, invisibility, charms, geas, and illusions." "why not?" "because I said so!" I mean, if it can detect magic, (which it should be able to do, considering that's the name of the spell) it should do just that. DETECT MAGIC. It isn't called "Detect Magic Treasure". It can find all magic if you look at it long enough. At least, thats how I play it. And with Nystul's, it matters even less if it can detect invisibility. Just cast it on yourself followed by Nystul's next round, and then you have no aura.

Krimm_Blackleaf
2008-12-05, 07:40 AM
I don't in any games I run. My basic rule for detect magic is that you have to actually be able to see the item itself. In some cases I'll let the magic aura permeate things that are thin enough, if the aura's powerful enough(or there are magic items in giant gold piles).

mikej
2008-12-05, 07:51 AM
Ideally Noo, but in my opinion I find sending invisible foes at the party redundant. If the party has one caster its pretty safe to assume its going to be a challenge to send invisible enemies anyways. The only time I haven't had that tactic ruined quickly is when my players thought a party consisting of a Monk, Archer, CW Samurai was good. That quickly change after I send a invisible demon.

Curmudgeon
2008-12-05, 02:17 PM
To pick pocket the caster's wands and scrolls and use them against their owners of course:smallbiggrin: I thought that went without saying, so I didn't. :smallcool:

Tacoma
2008-12-05, 02:35 PM
Er, you do realize that Detect Magic is so low level it doesn't have any business trumping anything or having a super effective application? I mean, it's a cantrip. Like Dancing Lights. You're lucky it does anything beyond letting you pick the magic loot out of the pile.

monty
2008-12-05, 02:57 PM
Er, you do realize that Detect Magic is so low level it doesn't have any business trumping anything or having a super effective application? I mean, it's a cantrip. Like Dancing Lights. You're lucky it does anything beyond letting you pick the magic loot out of the pile.

Prestidigitation. One of the best spells in the game.

Alternately, Silent Image with the gnome sub level. Never run out of uses for that one.

Avilon Rayne
2008-12-05, 03:29 PM
So much animosity towards a simple spell...

I allow players to use the spell exactly as it's written. If they come up with a creative use for it, good for them! If they don't, well, that just makes my job easier. ^^

As for what it can detect, do be sure to keep in mind that, at most, it tells the strength of the aura (and thus a spell level range, in increments of 3), the school of the aura, and the location of the aura. Invisible things thusly detected will still be invisible, will still catch their opponents flat footed, and will still have concealment. *shrugs* If you want to use 3 turns to find the invisible monster, by all means, go for it! Or, you know, buy those goggles that let you see invisibility permanently. Why do with spells what you can instead do with cash?

Hmmm... what have others said... oh yeah! Wall of Stone. That's a lovely spell isn't it? A nice little instantaneous duration conjuration that leaves a lingering aura for a whopping 1d6 minutes. After that? It's stone. It's a wall. It's non-magical.

Ohboy! Enchantments! I love enchantments. Did you know that the only thing revealed by Detect Magic is that the person has an enchantment on them, and approximately what power level the spell is? Is that minor aura a Suggestion or a Heroism? Is that moderate aura a Greater Heroism or a Geas? We just don't know! ^^

Someone mentioned something about breaking concentration to tell people where the invisible thing is... Out of curiosity, do you read the books? On page 176 of the PHB: "Concentrating to maintain a spell is a standard action that does not provoke attacks of opportunity." On page 144 of the PHB: "In general, speaking is a free action that you can perform even when it isnít your turn...Speaking more than few sentences is generally beyond the limit of a free action." It then goes on about getting more descriptive taking as much as a move action or full round action. So, move action to be extra descriptive, and standard action to concentrate. Tada! You have now become the detector of not-very-mobile magical auras...and you're done for the round... oh, and don't forget your munchkin moonwalk. That extra 5 feet a round might help you keep auras in your cone!

For my closing statement: Waffles. That is all.

Raum
2008-12-05, 03:37 PM
So, with that said, how do you handle it in your games? Has it ever even come up?Sure. It's not terribly useful in combat though.

Round 1: Hey, there's something magic over there!
Round 2: There are two sources, one is moderately powerful...
Round 3: The other is weak but they're both in my face! My knowledge of Spellcraft would probably tell me the type...of course that's moot now that I've got a sword in my throat.

All that assumes the invisible person never moves out of the cone. It's also worth pointing out that the +1 sword being carried by the invisible assassin has a stronger aura than the level 1 spell. Worst of all (for the victim) it requires concentration. So he's not doing much during those three rounds.

It's most useful as a warning. "Something is out there." As a GM, you can use that to build tension. :)

Person_Man
2008-12-05, 04:24 PM
Every DM/Storyteller/Gamemaster/etc I have ever met in every role playing game I have ever played has allowed me to use a bag of chalk dust or soot to locate and mark an Invisible enemy (although their house rules for how much of an area the dust covers varies wildly).

Also, it's worth mentioning that in each edition of D&D there are many different methods of defeating Invisibility. It's a plot device and a modestly useful combat buff. Who cares if your PCs want to use Detect Magic or Glitterdust or a Listen check or any of the various cheap magic items or making it rain somehow or some other clever idea to defeat it? If you want to force them to use the Red Key and only the Red Key to open the Red Door (which for some reason you can't just bash down or shoot or whatever) go play a video game. There's nothing broken about being clever.

metagaia
2008-12-05, 05:04 PM
As many other people have said, when in combat is the wizard going to sit still for 3 rounds not casting to find what might very well be a magic mouth cast onto the floor.

I guess if it wasn't for the 3 round thing, it would need to be bumped up a couple of levels...if only we had something like arcane sight!

The weakness of glitterdust is it's small radius for hitting a creature whose location is unknown, and it's large radius with respect to hitting your own party. Enlarge spell and sculpt spell do deal with that, but at that kind of level invisibility is not a problem anyway.

Shhalahr Windrider
2008-12-05, 05:06 PM
While I see what you're saying, it could be the party is actually defending the wizard during this time. Not that that's a good excuse, but it can be done effectively sometimes, even against an invisible creature.
So the rest of the party can see invisibility, but the wizard doesn't? So why does the wizard need to be doing this again?

Even then, it's not necessarily a matter of attacking the caster using the detection as it is simply getting out of the area of effect. At which point, the caster has to realign the area and start focusing from the beginning.


EDIT: But forget that "3 rounds concentration" garbage. You cast it and now you see auras within 60 feet until the duration is up. I like a spell to be actually usable but narrowly defined rather than a catchall that you can never use because it must be Monday the 12th and the moon must be in the east.
Seems pretty narrowly defined to me. "You see magic auras and can potentially identify what school they belong to." Nothing more, nothing less.


Er, you do realize that Detect Magic is so low level it doesn't have any business trumping anything or having a super effective application?
So what is it trumping and what is it so super effective about it again?


There's nothing broken about being clever.
And there's really nothing clever about using detect magic to search for a potentially mobile, hard to pin down, illusion aura. It's a last resort at best. And a pretty crappy one at that.

Weiser_Cain
2008-12-05, 05:21 PM
This intrigues me. I had always known of the three standard types of invisibility:

1: Light bends around him via illusion.

2: The covered object is blocked from the target's mind, so it includes all senses.

3: The covered object has coloration exactly like what is behind him from the perspective of every observer.

But lo!

4: The covered object is clear and light passes through.

Good gravy, my mind hath been blown.

Of course one could argue that if you weren't made of molecules then you'd be invisible. I'd call that "out of phase" or "ethereal" in the sense that you can't backstab.
Did I do that?

Runolfr
2008-12-05, 05:48 PM
Now, I know by RAW detect magic (http://www.d20srd.org/srd/spells/detectMagic.htm) can locate invisible creatures, since it reveals magical auras for any magical effects within range. That's not what I'm posting this to debate or gain opinions on. Rather, I'm more interested in if you allow or don't allow this for whatever reason you may have.

Having done a quick comparison of the spells, I don't see any reason not to.

1) Detect magic has a much more limited range, 60 feet instead of line of sight.
2) Detect magic is pretty useless in the situation in which you would most want to be able to see invisible things, in combat. You can't attack or cast spells while concentrating on detect magic, so you will be useless for three rounds while you try to locate the source of the magic aura of an invisible opponent. Even then, you basically get the square they're in, so they still have full concealment, and as soon as you try to do something to them, you lose track of them again and your spell ends.

You might try to use detect magic to find something invisible as an act of desperation, but it's a very poor substitue for see invisible.

ericgrau
2008-12-05, 10:03 PM
For the reasons everyone mentioned, this is far from an overpowered way to find invisible creatures. Plus it is perfectly legit by the rules. Plus the official FAQ confirms it. Houston we are go to launch.

Roderick_BR
2008-12-05, 11:12 PM
Yes, and no.
By what I understood, detect spells are like an extra sense, not a visual effect (as it apparently was in AD&D). If you are using detect magic, and turn your gaze to a place with something magically invisible, you'll "know" that something is there. You doesn't know the exact place, but as know it's general direction, and even risk attacking it's space in a map grid, but you doesn't "see" the aura. You just know it's there. With the 3 rounds thing, you can pinpoint a more exact place, though you still sufers the penalties from fighting someone/something invisible.
So, I let detect magic work as a "sixth sense" rather than a radar.