Magic Sense

[Merlion]

As you all no doubt know a staple concept of fantasy literature is that the use of magic can be sensed, detected or "heard" by other magicaly inclined individuals or beings.
DnD doesnt really have anything that resembles that. I think it would be interesting to try and create a mechanic for this and I just thought I'd throw out the net for ideas and suggestions and to see if anyone thought their might be balance issues.
I thought about creating a spell for it. And that might work, especialy for basic DnD. However also, the campaign I plan to run is already pretty different from standard DnD, and in addition to the possible spell I would also like to try and develop some generalized mechanic by where all spellcasters and exrremely magical beings are just innately able to sense the use of supernatural forces(and have theirs sensed in turn).
It would be a very general sense....general direction, strength and maybe some inkling of the type of magic involved. Also especialy in my campaign perhaps an indication of alignment especialy in extreme cases( the supernatural and spell like abilities of fiends for example). Radius is a big thing...I was thinking perhaps a mile per 3 character levels or so.
Tell me what you think guys

 

[willpax]

I have a system that does just that, but it has so many other variants that you may not find it useful.

The mechanic, translated into standard magic, might be as follows:

Roll arcane awareness skill (wis bonus, trained only, a class skill for wizards only) against the following DC:

10 - (level * 2) + (miles between sensor and spell). DC cannot be lower than 1.

The amount by which the roll suceeds determines the amount of information gained. Types of information include general distance away, general direction, power level of spell, and the "magical signature" of the caster (every caster has a certain unique feel, although I also have a feat that allows a caster to learn a second signature). Extraordinary success would allow the sensor to know the exact location of the target (well enough to target a scry).

In the game, it has had the desired effect: the magic user gets very paranoid whenever he is called upon to wield powerful magic, and he always seeks for non-magical solutions to problems first. It has also worked to the party's advantage, because the mage has sensed other magicians in the area in time to give some warning.

 

[Merlion]

10 - (level * 2) + (miles between sensor and spell). DC cannot be lower than 1.

I dont quite follow this part. the level of the one attempting the check? and whats the *2 represent?

Actualy this is very helpful. I would probably have it be a level check instead of a skill but yes this is a good start.

 

[SylverFlame]

Well, DnD does cover this issue. The spell Detect Magic does what you want.

That said, you have to cast the spell and get into the whole bru-ha-ha of that.

Why not just go with the good ol'hairs on the back of you neck bit? Cliche, but it works. The bigger the spell, the lower the level needed to detect it and the detection is from a farther range.

For instance: A level 9 spell is detectable by all things magical (wizards, dragons, magical beasts, outsiders, etc.) from a range of a few miles. An 0-th level spell, however, requires a higher magical level (the energy isn't as concentrated) and is felt within the same room (about ten feet) due to the same reason. Less mechanics, and no rolls to fiddle around with.

 

[Merlion]

Detect Magic doesnt cover what I am going for at all really.

But yes, something like that. I am considering many possibilities...thats why I posted...to get many different takes. I will probably end up using something very intuitive.

 

[haiiro]

I don't know if you've seen seasong's "House Rules Reference List" thread yet, but he's got a feat called Mystic Scent in there that is something like what you're after. Here's the link: http://enworld.cyberstreet.com/showthread.php?s=&threadid=49210 (the feat is a little ways down the page).

 

[willpax]

The DC formula: 10 - (level * 2) + (miles between sensor and spell). DC cannot be lower than 1.

level= level of spell being cast (I use a vitality point system, so I just use the number of points used in the spell--level * 2 could work, or you could adopt some arithmetic or exponential scale if you want your really powerful spells to have long-range effects; level squared might be nice--even neophytes would be feeling a ninth level spell seventy miles away, while first level spells would generally pass unnoticed).

Aside from Seasong's excellent page, the Middle Earth d20 conversion page (whose address I cannot remember) has some rules on this phenomenon.

 

[Merlion]

Ahhhhhhhhhhh. I see now. thanks.