If I cast detect magic in a circle around myself, can I see the aura of my own spell and thus know where it ends?
[RPG] Does the Detect Magic spell detect itself
dnd-5emagicspells
Related Solutions
No, it can't. Animate dead and similar spells typically have a duration of instantaneous. This means the magic is only present at their creation (and for more powerful spells/spellcasters, an aura may linger for a time). After that, the negative energy has already infused the creature and made it undead - this is a "natural" (stretching the term quite a bit) state for an undead creature, and requires no ongoing enchantment to keep it functioning.
A lot of confusion on this issue stems from the fact that the only way mortals (read: your PCs and the vast majority of NPCs) can manipulate positive and negative energy is through magic. But a dead body infused with negative energy in other ways can become undead without any "magic". A deity capable of manipulating negative energy directly can just push the energy into the creature. A place where lots of dark things have happened can naturally attract negative energy, and people who die there may rise as undead. Some undead can "infect" living targets with negative energy carried by a natural vector, like a disease or poison (like plague zombies). None of these require any magic to create the undead.
Basically, animate dead just "starts the engine", the creatures can "run" without any more magic.
No, detect magic doesn't automatically detect spellcasters as magical
The Sage Advice Compendium addresses a related question:
Is the breath weapon of a dragon magical?
If you cast antimagic field, don armor of invulnerability, or use another feature of the game that protects against magical or non-magical effects, you might ask yourself, “Will this protect me against a dragon’s breath?” The breath weapon of a typical dragon isn’t considered magical, so antimagic field won’t help you but armor of invulnerability will.
You might be thinking, “Dragons seem pretty magical to me.” And yes, they are extraordinary! Their description even says they’re magical. But our game makes a distinction between two types of magic:
- the background magic that is part of the D&D multiverse’s physics and the physiology of many D&D creatures
- the concentrated magical energy that is contained in a magic item or channeled to create a spell or other focused magical effect
In D&D, the first type of magic is part of nature. It is no more dispellable than the wind. A monster like a dragon exists because of that magic-enhanced nature. The second type of magic is what the rules are concerned about. When a rule refers to something being magical, it’s referring to that second type. Determining whether a game feature is magical is straightforward. Ask yourself these questions about the feature:
- Is it a magic item?
- Is it a spell? Or does it let you create the effects of a spell that’s mentioned in its description?
- Is it a spell attack?
- Is it fueled by the use of spell slots?
- Does its description say it’s magical?
If your answer to any of those questions is yes, the feature is magical.
Let’s look at a white dragon’s Cold Breath and ask ourselves those questions. First, Cold Breath isn’t a magic item. Second, its description mentions no spell. Third, it’s not a spell attack. Fourth, the word “magical” appears nowhere in its description. Our conclusion: Cold Breath is not considered a magical game effect, even though we know that dragons are amazing, supernatural beings.
Detect magic, like other game mechanics, operates by this same logic with regard to what is considered magical. The spellcasting abilities of creatures (innate or otherwise) are considered "the background magic that is part of [...] the physiology of many D&D creatures". Detect magic is designed to detect magical effects, not the background magic that suffuses creatures or the universe.
Chris Perkins confirms this sort of interpretation here:
Can detect magic detect magic potential of spellcasters even if they're not actively casting a spell?
It's not a wizard detector, if that's what you mean.
Given that the question he's responding to asks about spellcasters in general, it seems clear that his response is not specific to wizards - he's suggesting that the spell doesn't automatically detect spellcasters simply due to their magical abilities.
Best Answer
If anything, you would see a divination aura around your own body.
To the extent that Detect Magic has a target, the target is you, the caster. The 30-foot sphere is not the target, but simply the range of the special sense granted to the caster by the spell. (By analogy, consider what Detect Magic would see for a Darkvision spell.) So, if you held your hand up in front of you while using your action to see magic auras, you might see the spell's own divination aura around your own body, but the spell itself would not produce any other aura.
You might see nothing at all
Consider that the always-on magic-sensing feature of the spell would be completely useless if the spell detected itself, since it would always detect some magic within 30 feet 100% of the time. It would be logical to extend that self-exclusion to the aura-viewing feature as well, especially since doing so has no mechanical impact. In this case, you would not see the spell's own aura, although another wizard casting Detect Magic would see the aura on you (and you would see theirs).