Problem Spell: Detect Magic

[LordHenry]

How do you handle Detect Magic in certain circumstances?

- Do you allow to see invisible creatures?
- Magic traps: I personally do not allow to detect magic traps with it, but would it be allowed RAW-wise?

And, finally: Alarm spell:

How can you actually find it (possibly without triggering)?

Is it considered a magic trap?

[Zharradan Marr]

You will definitely see the aura of an invisible creature, and be able to detect that "there's something magical over there". You won't be told specifically that it's an invisible creature, but can make an educated guess, especially if you make a Spellcraft check and get "Illusion". You still have the 50% miss chance.
As for traps and alarm spells, you, again, can see a "magic aura on the doorway", but won't necessarily know it's a trap, let alone an Alarm spell (but if you make a Spellcraft check and get "Abjuration", you can make a good guess)

If that bothers you a lot, remember, spellcasters have access to the Magic Aura spell.
http://www.d20srd.org/srd/spells/magicAura.htm

[Rhynn]

First off, read the spell description (http://www.systemreferencedocuments.org/resources/systems/pennpaper/dnd35/soveliorsage/spellsDtoE.html#detect-magic) carefully. Particularly these parts...


Area: Cone-shaped emanation
Duration: Concentration, up to 1 min./level (D)

1st Round: Presence or absence of magical auras.

2nd Round: Number of different magical auras and the power of the most potent aura.

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. (Make one check per aura; DC 15 + spell level, or 15 + half caster level for a nonspell effect.)

Each round, you can turn to detect magic in a new area.


- Do you allow to see invisible creatures?

Not "see," no. You can detect the magic auras, yes, but on the 1st round of concentration, you can only tell that there is a magical aura. On the 2nd round, you can tell how many there are, and how potent the most powerful one is. So if there's only one, you might detect that it is faint (a 3rd level or lower spell). On the 3rd round, you'd get a Spellcraft check if the invisible creature is within your LOS to determine that it's an Illusion spell aura, and could pinpoint the location, but you wouldn't even have confirmation that it's invisiblity, just that it's an Illusion spell of 3rd level or lower!

And all that requires the target to stay in the cone you're detecting in (turning to a new area may restart the counter, that's slightly interpretative; I'd rule that it does, absolutely). If an invisible creature is staying put for 3 rounds to let you detect its aura, it's probably not trying to hurt you anyway.

All in all, just by the rules, detect magic is incredibly bad for defeating invisibility.

edit:
Also, pointing out your suspected invisible creature to others is tricky. At the very best, while it's staying put and you're on the 3rd round of scanning that same 90 degree cone, you can try to point out its location to others, but you're going to need to do it in a way they can understand. "15 feet straight ahead of me" works, as does "next to the table, on my side" and so on. But in the best of circumstances, your allies know what square the supposed invisible creature is in. Miss chances still apply.

Also note that invisibility can be cast on objects, and detect magic won't differentiate...
/edit


- Magic traps: I personally do not allow to detect magic traps with it, but would it be allowed RAW-wise?

Probably not a trap that's not been triggered, no... it would depend, I suppose. Magic items and functioning spells are detected. Some traps are actually functioning spells.


And, finally: Alarm spell:

Detect magic would detect alarm as a faint aura, Abjuration school, if the emanation or part of it is in the cone of detection.

It's very important to pay attention to how detect magic actually works! It does not provide accurate or specific information, and it requires long concentration to provide even slightly useful information.

[Diarmuid]

Used as it is written, I dont think the spell has any problems.

If you as the DM are not making the players jump through the necessary hoops and/or are giving them more information than they should be getting...then yes I could see how it could be problematic.

I'm personally in the camp that it should be able to detect magical traps, but only insofar as what the spell can actually detect.

It'll tell you there is magic in an area
It'll tell you how many magics are in an area and how strong the strongest in the area is
It'll tell you the location and strength of each aura in the area

Then, if a spellcraft check is passed (individually for each separate aura) what school for each aura.

So knowing that there is a Moderately Powerful Abjuration over there doesnt tell you that there's a Greater Glyph of Warding in place nor what kinds of actions will trigger it. Heck, if the caster level of the Glyph were 13th or higher it could, in theory, trigger before you got within range of it with your Detect Magic.

[Slipperychicken]

The others here seem to have answered your question about as well as I could.



It's very important to pay attention to how detect magic actually works! It does not provide accurate or specific information, and it requires long concentration to provide even slightly useful information.

The PF version of Detect Magic is godly, though. It's at-will, and even identifies items' powers if you can make a spellcraft check. Just spam it all day (I mean, you'd get tired from uttering the verbal components all the time, but still).

[Emperor Tippy]

These all being reasons why smart people pay for the Permanent Invisible (unless you want your eyes to glow blue) Arcane Sight.

It tells you all of the information that Detect Magic does except Arcane Sight does it instantly and at twice the range.

Although Persistent Greater Arcane Sight is even more fun. That instantly and automatically tells you what spells and magical effects are active on anything that you see that is within 120 feet (240 if Widened) feet of you.

Persistent Analyze Dweomer is also lots and lots of fun. Sure you only get CL uses out of each casting but it is massively powerful when facing enemy casters (as you get to learn all of their buffs with no save and no SR).

[ksbsnowowl]

Although Persistent Greater Arcane Sight is even more fun. That instantly and automatically tells you what spells and magical effects are active on anything that you see that is within 120 feet (240 if Widened) feet of you.

Minor off-topic quibble, but you cannot Widen Greater Arcane Sight.


Widen Spell [Metamagic]
Benefit: You can alter a burst, emanation, line, or spread shaped spell to increase its area. ...Neither Arcane Sight nor the Greater version are bursts, emanations, lines, or spreads.

[OldTrees1]

This is the reason high level rogues shun invisibility like the plague.

[ericgrau]

How do you handle Detect Magic in certain circumstances?

- Do you allow to see invisible creatures?
- Magic traps: I personally do not allow to detect magic traps with it, but would it be allowed RAW-wise?

And, finally: Alarm spell:

How can you actually find it (possibly without triggering)?

Is it considered a magic trap?

1. (after 3 rounds) There is an illusion somewhere in that square.
2. (after 3 rounds) There is an abjuration somewhere in that square
3. (after 3 rounds) There is an abjuration somewhere in that square

It doesn't tell you precisely what the thing is and it doesn't let you see it, whether it's a creature or a trap. You can attack the invisible creature if it hasn't moved in 3 rounds, but it still gets a 50% miss chance for total concealment. And you're not even sure you're hitting a creature, it might be a silent image. You don't "find" the trap as would with a search check, and can't then attempt to disable it because you don't know anything about it only that it's in such and such square. You're not even sure it's a trap. Though knowing that something weird is there may make you go around.

[kirerellim]

I have found detect magic to be a real pain for making traps. So I stopped making them magical and laughed and laughed and laughed.

[Crake]

Make the triggers for your magical traps mechanical. They have detect magic running, they see an aura at the end of the hall, the walk towards it, step on the pressure plate and set off the acid arrow trap flying down the hall.

[Gemini476]

Make the triggers for your magical traps mechanical. They have detect magic running, they see an aura at the end of the hall, the walk towards it, step on the pressure plate and set off the acid arrow trap flying down the hall.

Why not just have the entire hallway be precariously balanced on a hinge, so when they get past a certain point (halfway, for instance,) they fall right towards the obvious magical trap?

Or set your Glyph upon a trolley that hurtles towards them at greater than run speed, or have the real trap be that there's a nonmagical Invisible Wall of Stone coming silently from the side on greased rails to crush them against the wall of the hallway.

It's not hard to make difficult traps. The difficulty is keeping them beatable yet challenging.

Or you could just make a hole in the wall that has a switch that, when pulled, chops your hand off. Or just collapse the hallway as if it was a fake entrance to the Tomb of Horrors.

I personally like the traps that are harmless within five feet yet deadly at ten feet away. Or the Mimic Room, but that's just because it's so ridiculous.

[Chronos]

It's also often plausible to have an adventure location that is entirely magical. Yes, the door registers a necromantic aura. So do the walls next to it. So does the floor, and the ceiling. So does the door you just came in through. So does the human-ribcage chandelier hanging from the ceiling. So does that sarcophagus in the middle of the room. Some of those auras might be due to traps-- Wanna guess which ones?

[Tommy2255]

It's also often plausible to have an adventure location that is entirely magical. Yes, the door registers a necromantic aura. So do the walls next to it. So does the floor, and the ceiling. So does the door you just came in through. So does the human-ribcage chandelier hanging from the ceiling. So does that sarcophagus in the middle of the room. Some of those auras might be due to traps-- Wanna guess which ones?

But is there a way to do that that doesn't involve actually making everything into a magic item of some sort? Because that could get expensive. I suppose you could make the whole place out of Wall of Force spells, then put a layer of stone over it, or make your walls out of bone, but the prices given in the Stronghold Builders Guidebook are 40,000 and 6,000 gp/space (less if you can cast Wall of Force yourself, but still). I can see that for the villain's main room where he does most of his villaining (bone walls can give a Desecrate effect) or permanent walls of force for exterior walls, but I'm not sure he'd bother for every room.

[ericgrau]

Even without getting too crazy dungeons can have a lot of magic in them. Is it a trap? Treasure? An enemy's gear? An illusion? A magic mouth? Who knows.

[Chronos]

The simplest way to get an aura on everything is to cast Hallow/Unhallow. Which does have a cost, but not all that great of one for an entire lair.

Or you could cast spells like Magic Mouth on everything in sight, which costs nothing but spell slots and time.

[georgie_leech]

Or you could cast spells like Magic Mouth on everything in sight, which costs nothing but spell slots and time.

What sort of necromancer's lair doesn't have the whispers of the damned pervade the dungeon?