Anti-Magic Field Question

[Comoke1024]

Hello all! I have a question about the Anti-Magic Field. At what point would a spellcaster know or suspect that they are in an anti-magic field if they did not see it being cast?

Would they know instantly upon entering?
Would they only come to know if they attempt to cast a spell? If the spell has no visible effect upon failure, would it be reasonable for the caster to believe that they just failed the spell? Such as Charm Person, maybe?

If the neither of the above is correct, what would have to happen before they begin to suspect?

I suspect that they would only be able to attempt a spellcraft check after they come to believe that one is in place, is that right?

Thank you for your help!

[Uncle Pine]

If I were a Sor/Wiz, I'd know I walked into an AMF as soon as my shrinked tinfoil hat dropped on my person, which would happen immediately.

If I were anyone else, I'd notice as soon as my usual source of light (any item affected by continual flame, or a magic weapon that normally sheds light) turns off. Or when my ghost fellow winks out, whichever happens first.

EDIT: If a spellcaster were to cast a spell within an AMF without knowing he's inside an AMF, he'd be entitled a Spellcraft check to identify the AMF (DC 20 + spell level) as per Spellcraft's rules. However, a truly paranoid spellcaster will immediately think of an AMF regardless of the result of the skill check.

[Calthropstu]

It's a tricky question to answer correctly. When your magic items stop working how is that percieved?

Obviously when the rogue's belt of dexterity gives out his movements become less swift... but is it felt? Can it be seen or noticed by his companions?

Obviously when the flying wizard falls, it is known something happened. I chalk it up to high dc perception check, reducing dc for each magic item with a continious effect or spell active affected.

[Duke of Urrel]

Hello all! I have a question about the Anti-Magic Field. At what point would a spellcaster know or suspect that they are in an anti-magic field if they did not see it being cast?

Would they know instantly upon entering?
Would they only come to know if they attempt to cast a spell? If the spell has no visible effect upon failure, would it be reasonable for the caster to believe that they just failed the spell? Such as Charm Person, maybe?

If the neither of the above is correct, what would have to happen before they begin to suspect?


An Antimagic Field doesn't target creatures; it affects spells, spell-like abilities, and supernatural abilities by suppressing them. So I would say that there's nothing for any creature to notice about an Antimagic Field until one of these things stops functioning in a noticeable way. According to the rules (http://www.d20srd.org/srd/magicOverview/spellDescriptions.htm#savingThrow), you instantly notice if you cast a spell that targets a creature and the creature makes its saving throw, but in all other cases, you don't notice unless the spell's failure is obvious or becomes obvious. For example, if you think you have charmed a creature, but it continues to attack you or act unfriendly toward you, you know that it has not been charmed, after all. Moreover, if you didn't feel that the creature made its Will save against your Charm Personspell, you can deduce immediately that something else caused the failure – something like the Antimagic Field spell.


I suspect that they would only be able to attempt a spellcraft check after they come to believe that one is in place, is that right?

Thank you for your help!

After you notice that a spell has failed, you can make a Spellcraft check to identify the cause of failure (which could after all be any one of several spells, such as Lesser Globe of Invulnerability, Globe of Invulnerability, or Antimagic Field). But you have to notice that a spell has failed before you can make this check, because "[y]ou must be able to see or detect the effects of the spell" in order to use Spellcraft (http://www.d20srd.org/srd/skills/spellcraft.htm) to identify it.

[Eldariel]

Depends on your vision modes. Arcane Sight should be able to perceive the spell - nothing about Antimagic Field leads me to believe that it blocking magic would somehow negate its own aura. So if you see a 10' radius Moderate Abjuration emanation in an area where no other auras appear to be present (due to being suppressed), well, it's a fair guess you're looking at Antimagic Field. Of course, you'll only know it's an Abjuration if you have line of sight to its carrier (and can make the trivial Spellcraft-check) but the aura itself is distinctive enough that you should be able to figure it out. Of course, if we're talking about a target with AMF and multiple other auras, such as an Initiate of Mystra or someone with Invoke Magicked buffs, it becomes slightly less obvious - though a complete lack of magic item auras is generally still a dead giveaway. Without a way to see magical auras, probably the second one of his minions/spells/items ceases to function or any of the Contingency/Spell-based defenses activates.

[Duke of Urrel]

Depends on your vision modes. Arcane Sight should be able to perceive the spell - nothing about Antimagic Field leads me to believe that it blocking magic would somehow negate its own aura. So if you see a 10' radius Moderate Abjuration emanation in an area where no other auras appear to be present (due to being suppressed), well, it's a fair guess you're looking at Antimagic Field. Of course, you'll only know it's an Abjuration if you have line of sight to its carrier (and can make the trivial Spellcraft-check) but the aura itself is distinctive enough that you should be able to figure it out. Of course, if we're talking about a target with AMF and multiple other auras, such as an Initiate of Mystra or someone with Invoke Magicked buffs, it becomes slightly less obvious - though a complete lack of magic item auras is generally still a dead giveaway. Without a way to see magical auras, probably the second one of his minions/spells/items ceases to function or any of the Contingency/Spell-based defenses activates.

I disagree. The Antimagic Field spell suppresses the effects of all spells within its area, and that should include Divination spells, I think.

EDIT: On the other hand, Eldariel may have a point with the Arcane Sight spell. This is a Personal spell that bestows the power to see magic auras upon the spellcaster. So as long as you, the spellcaster, are outside an Antimagic Field, you should still be able to use Arcane Sight. But if you enter the Antimagic Field, the Arcane Sight spell should be suppressed. Also, if you use the Detect Magic spell, which affects an area, you can't detect magic auras inside the area of an Antimagic Field spell, regardless of your location.

[Eldariel]

I disagree. The Antimagic Field spell suppresses the effects of all spells within its area, and that should include Divination spells, I think.

Arcane Sight, or vision mode spells in general, have Range of Personal and a Target of You. They have no Effect outside that. The vision mode itself is just an alteration in the caster, and the only way I see for AMF to interact with it is for the area of the spell to overlap with the caster. The vision itself should function unhindered except from actually inside the AMF. Even outside RAW (which I think is clear), logically eyes receive information. They don't actively broadcast any signals - eyes are a passive receptor, not an active detector. Arcane Sight just enables for them to receive a wider variety of information; not just reflected light but "magical radiation" as well.

EDIT: Ninja-edited. Well, it appears we're in an agreement then.

[Uncle Pine]

An Antimagic Field doesn't target creatures; it affects spells, spell-like abilities, and supernatural abilities by suppressing them. So I would say that there's nothing for any creature to notice about an Antimagic Field until one of these things stops functioning in a noticeable way. According to the rules (http://www.d20srd.org/srd/magicOverview/spellDescriptions.htm#savingThrow), you instantly notice if you cast a spell that targets a creature and the creature makes its saving throw, but in all other cases, you don't notice unless the spell's failure is obvious or becomes obvious. For example, if you think you have charmed a creature, but it continues to attack you or act unfriendly toward you, you know that it has not been charmed, after all. Moreover, if you didn't feel that the creature made its Will save against your Charm Personspell, you can deduce immediately that something else caused the failure – something like the Antimagic Field spell.

After you notice that a spell has failed, you can make a Spellcraft check to identify the cause of failure (which could after all be any one of several spells, such as Lesser Globe of Invulnerability, Globe of Invulnerability, or Antimagic Field). But you have to notice that a spell has failed before you can make this check, because "[y]ou must be able to see or detect the effects of the spell" in order to use Spellcraft to identify it.

You are entitled a Spellcraft check to "identify a spell that’s already in place and in effect. You must be able to see or detect the effects of the spell. No action required. No retry." (link (http://www.d20srd.org/srd/skills/spellcraft.htm)). Moreover, in addition to what you mentioned, AMF also suppresses magic items, the suppression of which could be more clear than that of some spells and SLAs.

If you cast a spell inside an AMF it doesn't fail. Instead, its effect is suppressed. That alone would entitle a Spellcraft check.

[KillianHawkeye]

My wizard (and anybody else in the vicinity) would notice immediately because he would see his hat of disguise stops functioning, which he constantly uses to make his garishly colored clothing look normal. That's the benefit of getting your clothing made in "danger" red or "construction zone" orange.

Also, five out of six of his ability scores are boosted by magic items, so he'd certainly notice at least some of those shutting off. And then there's his all-day overland flight and greater luminous armor spells and permanent detect magic. So yeah, pretty much immediately.

[Calthropstu]

You are entitled a Spellcraft check to "identify a spell that’s already in place and in effect. You must be able to see or detect the effects of the spell. No action required. No retry." (link (http://www.d20srd.org/srd/skills/spellcraft.htm)). Moreover, in addition to what you mentioned, AMF also suppresses magic items, the suppression of which could be more clear than that of some spells and SLAs.

If you cast a spell inside an AMF it doesn't fail. Instead, its effect is suppressed. That alone would entitle a Spellcraft check.

Actually reread AMF. No magic can be cast inside it. Spell effects that enter are suppressed, but magic can't be cast in it at all.

Also, it should be noted that in pathfinder, spellcraft does NOT have that wording. There is literally no RAW way to identify a spell after it has been cast. In 3.5, spellcraft will allow you to do so as you noted.

[Coretron03]

Actually reread AMF. No magic can be cast inside it. Spell effects that enter are suppressed, but magic can't be cast in it at all.

Also, it should be noted that in pathfinder, spellcraft does NOT have that wording. There is literally no RAW way to identify a spell after it has been cast. In 3.5, spellcraft will allow you to do so as you noted.

Greater arcane sight lets you do that but apart from doing the coven witches from leadership thing (Which is awesome) to get crazy caster level boosts the duration sucks.

[Uncle Pine]

Actually reread AMF. No magic can be cast inside it. Spell effects that enter are suppressed, but magic can't be cast in it at all.
I did, and I was right:

An antimagic field suppresses any spell or magical effect used within, brought into, or cast into the area, but does not dispel it. Time spent within an antimagic field counts against the suppressed spell’s duration.


Also, it should be noted that in pathfinder, spellcraft does NOT have that wording. There is literally no RAW way to identify a spell after it has been cast. In 3.5, spellcraft will allow you to do so as you noted.
OP didn't specify Pathfinder, so I assumed we were talking about 3.5e AMF. I do not know how AMF operates in PF, but it shouldn't matter in a 3.5 discussion, right?

[Calthropstu]

I did, and I was right:



OP didn't specify Pathfinder, so I assumed we were talking about 3.5e AMF. I do not know how AMF operates in PF, but it shouldn't matter in a 3.5 discussion, right?

I am looking at this: "Likewise, it prevents the functioning of any magic items or spells within its confines."

Some things, such as artifacts, can still cast spells, but the effect of those spells would be suppressed. So you cannot, for example, cast a fireball from inside the AMF to outside the AMF. But an artifact COULD, for example, cast a spell outside the AMF.

[Uncle Pine]

I am looking at this: "Likewise, it prevents the functioning of any magic items or spells within its confines."

Some things, such as artifacts, can still cast spells, but the effect of those spells would be suppressed. So you cannot, for example, cast a fireball from inside the AMF to outside the AMF. But an artifact COULD, for example, cast a spell outside the AMF.

The part of the spell description you quoted does not say what you think it says: everyone can cast inside an AMF, despite the fact that any spells cast inside an AMF is suppressed and doesn't function. You can, for example, try to cast a fireball from inside an AMF and spend the spell slot used to cast it, but that doesn't mean the spell you casted has any effect.

This is what the Rules Compendium says on the matter and should help understanding why you can cast a fireball from inside an AMF even though it wouldn't have any effect:

Spells don’t function in an antimagic area, but an antimagic area doesn’t block line of effect. If a spell’s point of origin is inside an antimagic area, that spell is entirely suppressed. When a spell’s point of origin is located outside an antimagic area, but part of that spell’s area overlaps the antimagic area, that spell’s effect is suppressed where the two areas overlap. Time elapsed within an antimagic area still counts against a spell’s duration.
If an instantaneous spell is entirely suppressed, that spell is effectively canceled. (It’s suppressed, and its duration instantaneously expires.) An instantaneous area spell is only entirely suppressed and effectively canceled if its point of origin is within the antimagic area. Otherwise it works like any other area spell that has a point of origin outside the antimagic area—only where its area overlaps the antimagic area is its effect is suppressed (and effectively canceled).
A wall of force, prismatic wall, or prismatic sphere isn’t affected by antimagic. Break enchantment, dispel magic, and greater dispel magic spells don’t dispel antimagic. Mordenkainen’s disjunction has a 1% chance per caster level of destroying an antimagic field. If the antimagic fi eld survives the disjunction, no items within it are disjoined.
Fireball is a 3rd level instantaneous spell. When casting fireball, a "glowing, pea-sized bead streaks" originates from your digit and shoots towards your target. As an instantaneous spell with a clearly defined point of origin, casting fireball while inside an AMF causes the spell to be entirely suppressed and effectively canceled. This happens regardless of whether your target is within the AMF or outside of it. This doesn't mean you can't cast while inside an AMF.
Compare this to what happens if you cast invisibility or some other buffs on yourself while inside an AMF: nothing actually happens because the spell is suppressed (not dispelled), but if you get out of the AMF before the duration of the spell expires, you'll become invisible.