Alternative to infinite detect magic

[Thelemic_Noun]

So, unlimited cantrips are in many ways a boon, and in some ways a bane.

When it comes to the bane, the most common complaint is how they render magic traps useless, unless every single one has a nondetection spell or other shenangians attached.

Notably, Kirthfinder turns detect magic into a touch spell.

One problem with that is how silly the mental images get. The royal wizard trying to screen guests for a contingencied fire shield primed to go off when the perp kisses the king's ring becomes a TSA-style groper.

So, here's a different alternative, and one that makes non-casters more useful.

Note that things like scrying sensors still follow their own specific rules. And identifying an aura that a character has detected functions as normal. Otherwise...

Magical auras are treated like invisible objects. Barring other factors like nondetection or large interfering energy fields, the fact that some kind of magical shenanigans are occurring within 30 feet is determinable with a DC 20 Perception check.

Magical auras are always considered to be "taking 10" on their "Stealth checks."

Weak auras gain a "size bonus" to their "Stealth checks" like so:

Dim: As a Fine object
Faint: Diminutive object
Moderate: Tiny
Strong: Small
Overwhelming: Medium.

Note that, as "invisible objects," magical auras gain a +20 bonus to the DC of Perception checks to pinpoint their location, even within 30 feet, and all a check tells you is the square it's in.

Multiple overlapping magical effects disguise each other. This works like the overlapping abjuration rules, but in reverse, and the penalty does not apply to the strongest aura. Abjurations don't disguise each other in this manner.

Effects such as magic aura and nondetection instead add the save or caster level check DC (minus ten) to the aura's "Stealth check."

Mundane effects such as lead that would block detect magic are a flat doubling (or +10 DC, whichever is a greater increase) to the Perception DC to locate or notice the effect. Don't forget the penalty for Perception checks through walls.

Detect magic allows the caster to use Spellcraft (modified by their main casting stat if it is better than their Int) to perceive magic auras, and grants a bonus on the check equal to their caster level +10. They may not make "passive Perception" checks other than to notice the presence of magical effects (the DC 20 check). They must make active checks (standard actions) to specifically find auras.

Arcane sight grants a +20 bonus rather than +10, and allows automatic checks for all eligible effects.

[Carla the Profane]

Interesting thought, but what are you trying to accomplish?

[Goth Guru]

Detect magic is almost useless in Equestria because all marks radiate magic. Many bloodlines, even for non sorcerers, radiate magic. If all Elves, Dwarves, and Gnomes radiate magic, then detect magic is back to what it's for, finding hidden goodies.
If you really want to mess with characters spamming detect magic, mage magic aura permanent till dispelled. Drow delight in casting magic aura on traps, non magic symbols, and click tiles.

[archmagi1]

Or just put in a houserule that allows you to obscure an aura for an opposed or DC caster level check to find.

[shadowkras]

A house rule of mine: You can only see the auras of things you have actually identified with a perception check.
If you dont know it's there, you cant see it's aura.

[Goth Guru]

I think the OP was upset with unlimited Detect Magic cantrips. Are you suggesting the 3rd round location of each aura be removed? Are you taking out the 1st round detection of the presence of magic too? That certainly counts as homebrew, but not my glass of peach iced tea.

[shadowkras]

No, they cannot detect auras on objects or creatures they havent seen or sensed yet. You cant find an invisible's creature aura because you cant see them, you cant find secret magic traps because you havent spotted them. You cant see someone buffed with spells inside a darkness area because you cant see in darkness. Etc. The auras simply dont show up because you have no signs of their existance at all.
You can only detect the aura on things you can clearly see or touch, or feel somehow (magic or otherwise).

You could detect magic on someone invisible if you also had See Invisibility active, meaning you could sense other auras on the target other than illusion, for example.

[Goth Guru]

Are you are reading something different than I am?
I finally found it. Line of sight is blocked by fog and darkness.
I did not know that it was different from line of effect by facing.

[Goth Guru]

Changes name of spell from Detect Magic to Detect Image and Magic.

[Liam Warner]

Honestly I don't have a problem with detect magic but then I tend to feel magic users should have an innate ability to sense magic anyway. Still to address your concerns here's two options . . .

1) Avoid the obvious.

Traps can be placed anywhere, sure doors are obvious choices but you can also place them on windows, chairs, floors, walls, desks, beds, treasure, chastity belts. Either the party is constantly detecting magic in which case their progress slows down ALOT allowing enemies to set up defenses/escape or they will miss some of these traps. Part of this does require intelligent enemies responding to an intrusion. If the party doens't reach point X in time instead of having the enemy leaders conveniently spread out to fight one on one they wind up facing all of them from an ambush.

2) Play it from the perspective of magical detection is common.

This one is how I run my games because I tend to remove detect magic and let all mages sense magic inately (also give thieves a chance of noticing traps when they aren't actively searching). The important things to remember here is that first all magic is going to be detected and second that people know all magic is going to be detected. This has two effects.

For the first I run magic as aura's not colours, that is to say you don't have a ring of detect magic siting there glowing a nice pretty blue it RADIATES it and how far/how bright is determined directly from the power of the magic. Think of it like a fire the flame from a matchstick is easy to see, from the sun less so and from a bonfire it gets hard to tell what flame comes from what stick. The higher the level the party and the more magical items they have the more they're going to be radiating their own magical auras making it hard to determine what exactly is what form of magic unless you spend time studying it. Sorcerers and other inately magical creatures tend to radiate their own magical power which further clouds the issue. Which doesn't even address the problem with more powerful items hitting hard (I'll get to that in the examples).

For the second given that everyones aware of the common ability to detect magic you wind up with two tiers of traps. The first is geared to the common man i.e. can be either magical or non magical but doesn't protect against magical detection. The second is geared to the magical man and has defenses against that. These can include such options as . . .

1) Magically trapped to respond to magical probing i.e. if someone uses detect magic/detect traps it goes off in the area of those spells.
2) Magically concealed e.g. undetctable aura for magical traps or dead magic/antimagic zones for mechanical ones.
3) Non-magically concealed e.g. encased in an inch of common metal or other rare elements to protect against magical probing.
4) Non-magical traps of exquisite design so that there's no magical aura to detect.

Examples
Okay now here's some examples of how I run it in my games.

Phase 1: Aura detection
A magic user actively looking for magic (detect magic or equivilent) automatically detects auras of magic in a 60' cone in front of them. They also are passively aware of magical auras in a X foot radius around them with X being level * primary casting stat modifier. All this does is tell them that there is magical auras present in that area (and has its own risks see below).

Phase 2: Number of auras and power level of strongest.
This is the 3rd round (passive i.e. noticed something and spent two rounds actively studying it) or 2nd round (active) when they start trying to determine just what exactly that magic is. In a 60' cone in front of them they are able to break auras apart by their different signatures and dtermine how many their are and how strong the strongest is. However because the auras are all flowing around each other they still don't know what is producing that aura.

Phase 3: Strength and location of each aura
Here's where things start getting a bit different to the book rules. On 4th round (passive) or 3rd round (active) they are able to start breaking things up into locations and determining the strength of each aura. The book makes a brief mention of stronger auras concealing weaker ones but doesn't really go into how so I run it as follows.

As its written on the 3rd round you know the aura comes from that ring. In my games you determine the LOCATION and an aura as I said radiates. Since there wasn't any rules for this I use the following . . .

Aura Radiation Rules
Original Strength Size of Radiated Aura
Faint 1d6 inches
Moderate 1d6 feet
Strong 1d6 * 10 feet
Overwhelming 1d6 miles

Obviously shielding/magical protection can conceal these auras but that is the location you determine. So lets say we have a magical ring with of 6th caster level its radiating its aura over a moderate distance i.e. 1d6 feet and concealing any faint auras in that area. Its also going to continue leaving a radiation over that area for 1d6 minutes whenever its moved so if our thief is wearing a ring of protection of 6th level and search's for traps you will need to wait 1d6 minutes for that rings radiation to fade before you can look for magical traps of moderate or lower strength. Similarly while you'll know there's a moderate aura of magic coming from that pile of treasure you'll have to narrow down the aura radius to figure out what item in its center is actually producing it.

Now generally these auras seem to be fairly solid spheres because I run them as pulsing on a round by round basis so you can narrow down the center by examining the limits of the sphere. That is a moderate ring every round pulses out to 1d6 feet and leaves its aura for 1d6 minutes. So its shrinking and expanding. The more powerful the item the longer the aura remains and the more your able to see its boundaries.

Now aura detection is a risky business because your opening your senses to a magically glowing object. A faint magical aura isn't a big threat although there's a good chance lower level mages will miss it with their passive detection because it only radiates a small distance and they can only automatically sense a small distance. Higher level mages can sense further but at the same time their own aura is going to mask the presence of weaker ones in that radius when trying to directly sense a particular item. So I think there was a spellcraft check of some sort to allow them too tune out familiar auras and look for new ones in that cloud.

RISKS

I haven't had a chance to run a game for awhile so I'd need to dig out exact rules however I ran it as a will save vs caster level with strong rendering you unable to detect magic for 1d6 minutes and overwhealming knocking the mage out if they failed. Can't remember the details though or what I had (if anything) for the weaker levels. A successful save negated the need for furhter saves against that particular aura till it left and re-entered your field of detection. As part of this there was the aforementioned spellcraft check when detecting magic vs a DC of 10 + caster level/spell level to tune out familiar auras. I vaguely recall I allowed that to be a one check for permanent familiarity even if having the aura suddenly pop up in your field of detection could blind you if you weren't expecting it (previous will save) similar to noticing red die in a glass of clear water.

[UnArcaneElection]

One thought I had for certain powerful Cantrips/Orisons, although I didn't have it for Detect Magic, is to have limited use Cantrips/Orisons. That is, the number of times you could cast them as Cantrips/Orisons (not counting or counting against castings from higher level spell slots) would be equal to the greater of your Cantrip/Orison or 1st Level Spell Slots (always the latter for spontaneous casters, since they don't have Cantrip/Orison slots). This would not impede you from casting other Cantrips/Orisons. I had thought of this for Summon Minor Monster and Summon Minor Ally, which used to be Cantrips/Orisons in 3.5, back when Cantrips/Orisons had limited uses per day (limited spell slots for spontaneous casters), and which thus got bumped up to 1st Level Spells in Pathfinder.

Maybe this would work in certain games for Detect Magic as well -- you have to watch how much you use it before you have to start burning higher level Spell Slots.

The Light Cantrip/Orison already has a sort of limited casting mechanic on it, but that one is different, just limiting the castings that can be running at once, which doesn't really help for Detect Magic.

For other solutions, I like some of the ideas above, including the permanent Magic Aura idea, although I wouldn't make Magic Aura permanent as it is, but add a "Greater" version that is permanent (of higher level, but still much lower than what you need for casting actual Permanency).

[dragonhunterq]

Continual det. magic worked for my party until about 3rd level when the Wizard realised he'd have to be in the front of the party to avoid pinging on the party magic items. slowing to a literal crawl to distinguish all the auras really annoyed everyone else, and there was no way the wiz was going to stand at the front for some reason - I thought that was a perfectly reasonable suggestion myself...

That and everyone who builds magic traps knows that detect magic is common and easy so they all have masked auras as standard, only a moron would build a magic trap without it.

[Goth Guru]

If a magic item is buried under gold coins you don't have line of sight. You can't identify the type of magic till you remove the coins.