D&D 5E Detect Magic and hidden (unseen) objects

[commandercrud]

You would know something nearby, maybe even specific enough that it's something in that bag, but without the glow, you wouldn't know it was that cloak specifically. If the PCs have time the DM can simply say you find a cloak that glows. But if they're in a hurry, that changes things, and the PCs may just grab the bag and run.

 

[Shiroiken]

Part of the purpose of requiring visibility is that it doesn't reveal the location of an invisible creature, just their presence. In the case of a magic item hidden somewhere, you'd get the indication that magic is around, and it'd be up to the DM if they gave you the specific location. I normally would, but if the players were to just constantly keep the spell active by ritual casting it over and over again, I'd not do so.

 

[Prakriti]

But to me the spell you tell you "hey, in the location of that sack is a magic item."

That's definitely not how the spell functions either RAW or RAI. It provides no directional sense. It just tells you that there is magic within 30' of you. If you or one of your party-members is carrying a magic item, then you will sense the presence of magic all the time. At that point, you will need to use an action to limn magic items with a faint aura to get any use out of the spell. But even then, it's still not directional. If you're facing in the wrong direction, for example, you won't see the aura.

Useless? Maybe. RAW/RAI? Definitely.

 

[DEFCON 1]

Useless? Maybe. RAW/RAI? Definitely.

Rules as Intended? I don't even think that's true. Cause that's just stupid.

If someone has a potion of healing on their person then they will never find anything else magical that isn't directly out in the open because the potion is filling up the 30' radius of "magic is here" all the time? That makes the spell even more useless than it is.

You want to say it's "RAW"? Fine, go ahead. (Of course I think anyone who worries about "only playing by RAW" is silly anyways). But to say that's how the spell is intended to actually work I think is also ridiculous. Because they wouldn't have gone through all the trouble detailing all that stuff that can block the penetration of the spell if the truth was the thing that actually blocked it was any single tiny magical item on the caster's person. It doesn't matter WHAT the barrier is made out of if the aura is blocked from sight and your entire 30' radius pings magical because you have a potion on you. Cause what's more likely to happen in-game that would need detailing in the spell description... the caster having another magical item on them, or items hidden behind walls of stone or lead-lined boxes?

But hey... you do you. Nerf it however you want.

 

[commandercrud]

Carrying a potion doesn't block sensing that there are other things. I think a caster would know the difference between sensing items they're carrying and the presence of something else new in the vicinity.

 

[Chaosmancer]

Carrying a potion doesn't block sensing that there are other things. I think a caster would know the difference between sensing items they're carrying and the presence of something else new in the vicinity.

Which is the point Defcon is making. If the spell does not include directionality, then casting the spell while holding a magical item essentially prevents you from knowing if there is any other magic in the area. Because the answer of "is there magic here" is always yes.

Actually, it gets even worse if you stop and think about. Detect Magic also detects magic on creatures, such as if a creature is concentrating on a spell. Like Detect Magic.

So, if we take this to the extreme of RAW, casting Detect Magic always turns up magic, because it detects itself. Which is dumb .

 

[commandercrud]

RAW/RAI makes perfect sense if you don't intentionally overthink it to absurdity just so you can claim its dumb to justify ignoring part of the spell. You can sense the presence of magic nearby. If you spend an action you can see an aura around the item assuming you can see the item at all. It should go without saying that the spell doesn't become totally useless if you happen to already posses something magical. If nothing glows, it's clearly hidden from view. Casting detect magic is not an instantaneous auto-finder of anything worth being hidden, you still may have to search the room.

 

[Chaosmancer]

RAW/RAI makes perfect sense if you don't intentionally overthink it to absurdity just so you can claim its dumb to justify ignoring part of the spell. You can sense the presence of magic nearby. If you spend an action you can see an aura around the item assuming you can see the item at all. It should go without saying that the spell doesn't become totally useless if you happen to already posses something magical. If nothing glows, it's clearly hidden from view. Casting detect magic is not an instantaneous auto-finder of anything worth being hidden, you still may have to search the room.

How do you know if there is something not glowing?

You cast detect magic in a treasure room. Your companion is wearing magical armor that glows when you focus. Is there any other magical items in the room you should search for?

You can detect magic through three feet of wood, so you are detecting magic in every wooden chest in the room, but you have no idea if you are actually detecting magic from them, because you companions armor is pinging.

Also any items you are wearing.
Any magical effects on you or your companions.

It makes the spell much harder to use, because the answer eventually becomes "Yes, you detect magic. Now, if you all strip out of your magical armor and move it into a pile 30ft away from you, you can then try and figure out if there is any new magic in the area"

 

[commandercrud]

I've never heard of any DM going down the path of "the answer eventually becomes..." That's the absurd part I'm talking about. The spell doesn't become stupid the instant your party gains its first magic item.

 

[Lanefan]

I'd allow it to pinpoint the magic source(s) if in line of sight (thus an invisible creature would glow if in LoS of the caster) but I'd be a lot harsher on what it can penetrate; the write-up is IMO far too generous there.

In the specific sack example I'd probably call for a Perception roll (without saying why) to see if anyone notices the very faint glow coming from the sack. That said, if the room was otherwise completely dark noticing it would be automatic while if in sunlight outdoors there'd be no chance at all.