Antimagic Field 3.5: What's That Function?

[Duke of Urrel]

The description of the Antimagic Field spell in the SRD (http://www.d20srd.org/srd/spells/antimagicField.htm) begins like this:


An invisible barrier surrounds you and moves with you. The space within this barrier is impervious to most magical effects, including spells, spell-like abilities, and supernatural abilities. Likewise, it prevents the functioning of any magic items or spells within its confines.

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.

Some questions about the Antimagic Field spell may be unanswerable, and others may have simple answers. I have a few questions about the text quoted above, but I have no idea whether the answers to them will be simple or hotly disputed until I ask the Playground. So here goes...

1. Does the Antimagic Field spell prevent the casting of a spell inside its area of effect, or does it merely prevent spells from taking effect inside its area of effect?

For example: Suppose I cast the Antimagic Field spell upon myself. Can I still cast the Fireball spell? If you believe I can, I have three more questions for you:


If I cast the Fireball spell while inside the Antimagic Field spell's area of effect and choose a point of origin for the Fireball's spread outside this area, does the spell still take effect everywhere except inside the area?


If I cast the Fireball spell while inside the Antimagic Field spell's area of effect and choose a point of origin for the Fireball's spread inside this area, does the spell still take effect everywhere except inside the area?


Suppose I cast the Delayed Blast Fireball spell while inside the Antimagic Field spell's area of effect, choose a point of origin inside the area of the Antimagic Field spell, set the fireball to detonate in one round, and immediately move 25 feet away. Does the Delayed Blast Fireball work as usual, exploding when my next turn begins? (I think it's safe to assume that if I move less than 25 feet or fail to move at all, I will still be protected from the effect of the Delayed Blast Fireball spell. But will the spell take effect at all?)

2. Does the Antimagic Field spell block lines of effect? Suppose I'm in a tunnel 10 feet wide. Suppose an ally of mine stands 10 feet directly behind me inside the Antimagic Field spell's area of effect and another ally of mine stands 20 feet directly behind me outside this area. Suppose a sorcerer casts the Lightning Bolt spell at all of us. I assume the effect of the Lightning Bolt cannot harm me or the ally who is 10 feet behind me, but can it harm the ally who is 20 feet behind me?

As always, I thank you for all the answers you give, but I am especially grateful if you give reasons why you believe your answers are right.

[trikkydik]

That's difficult, because it can be interpreted in 3 ways.

1.) Yes you can cast spells, although they have no effect inside your 10 foot radius.

2.) Spells can NOT originate inside an area affected by this spell.

3.) Spells can NOT originate inside an area affected by this spell, created by a hostile being. (meaning the caster can cast spells, thought they have no effect inside the radius, and enemies/allies can not.)

Good luck

Also, regarding the second portion of your post.

Yes the lightning bolt would travel through the dispel area and strike all creatures in its path. (Except for those inside the circle of antimagic.)

it's against the rules to post a snippet of the spell description, but it states that this spell only suppresses spells inside, and spells that enter the sphere function normally once outside the sphere.

[torrasque666]

it's against the rules to post a snippet of the spell description, but it states that this spell only suppresses spells inside, and spells that enter the sphere function normally once outside the sphere.
Ehh... not really against the rules. Not this case at least.

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Antimagic Field is from the SRD. Ergo, it can be freely reproduced.

[Rebel7284]

I believe the general consensus is that you can't cast inside an antimagic field. There are two ways around this. Initiate of Mystra feat and Invoke Magic 9th level spell.

Note that since instantaneous Conjuration effects are not effected by antimagic field, it may also be possible to shoot an Orb of Acid or such into an antimagic field.

Whether or not Antimagic Field blocks line of effect is contested. I believe the rules compendium does make a ruling on it that some people complained about. You can check it out.

[Duke of Urrel]

Thank you for your responses! Are there any more?

[Mato]

Yeah sure why not.

All of your examples are a no. Any spell with point of origin inside an AMF, even if it's area would extend beyond the field, is entirely suppressed. And if an instantaneous spell, such as fireball, and entirely suppressed than it is also effectively canceled.

This makes all of your examples inoperable. The point of origin in the case of fireball is both from the caster and from where the summoned bead explodes. And because all of your examples are casting within an AMF, putting the first point of origin inside the field, they are suppressed.

In the nitpicks of the rules however, the spells are only entirely suppressed and the ability to cast spells is an untyped class feature unaffected by antimagic. It's entirely possible to uselessly expend all your spell slots while with in an AMF, which while useless to the caster does provide a nonharmful means of disarmament to anyone capturing him. Of course, this is also how you can cast invoke magic in the first place however continuing the nitpick the spell doesn't provides any protection to it's self and it's effect is suppressed in an AMF anyway.

I feel like I've gone into a tangent that will only leave you even more confused than before. So let me simply say that AMF does not normally block spells but suppresses them. As a result you can generally do whatever you wish with your spellcasting, however the results of the spell simply never happen as long as you either cast while inside an AMF or in the case of spells like fireball while let you choose their emanation point happen to be centered within an AMF.

Which also leads me to your second question, AMF do not block line of effect. You can fire a fireball through an AMF and as long as you and the center of effect are outside it works normally (through any overlapping area is suppressed as normal). Just like if you cast haste outside an AMF an then proceeded to jog through a field the spell would continue to operate on the other side.

[Anthrowhale]

The Rules Compendium flatly states that AMF does not interrupt line of effect.

The prohibition on casting inside of an AMF is implicit based on the judgement that the act of casting a spell is magical.

There are several exceptions mentioned above. I believe this is the complete list:

Selective Spell (a feat or a class ability in Faerun) AMF should allow a caster to cast a spell inside of an AMF although such cast spells are still suppressed by AMF as normal.

Initiate of Mystra, as mentioned above, allows casting in an AMF _and_ allows the spells to take effect in an AMF.

Instantaneous Conjuration(creation) spells that take effect within an AMF are suppressed (since magic is used in their creation), but instantaneous conjuration (creation) spells that take effect outside of the AMF then enter the AMF are not suppressed (since magic is not used in their continuation).

Invoke Magic cannot generally be cast inside of an AMF, but if you cast it outside, then you are allowed to have an L4- spell of instantaneous duration take effect inside. Hence Selective Spell AMF + Invoke Magic is similar to Initiate of Mystra in effect.

If you are big enough that heads and hands can go outside the area of effect of AMF, then you probably can cast spells. Applying this rule is inherently a DM judgement because the location of heads and hands is abstract, but it is the plausible implication of this clause:


Should a creature be larger than the area enclosed by the barrier, any part of it that lies outside the barrier is unaffected by the field.

[Duke of Urrel]

Thank you all again.

1. Trikkydik, thank you for making it so plain to everybody why I was confused. It's nice to know that I'm not the only one to see ambiguity where everybody else sees only one possible interpretation.

2. Thanks to Rebel7284 and Anthrowhale for references to the Rules Compendium. The text that I should have read before is on page 11. According to this text, any spell effect that originates inside an antimagic field is totally suppressed, but a spell effect that originates on the outside can pass through it, because an antimagic field does not block line of effect. This is much clearer than the text in the SRD and the Player's Handbook.

3. Thanks to Mato for reminding me that a spell may have more than one point of origin. One point of origin is always the spellcaster, but a spell may also originate from some other point designated by the spellcaster. This makes sense and explains why I cannot cast the Fireball spell from inside an antimagic field, regardless of where I send the incendiary ball of sulfur and bat guano, because I am myself always a point of origin for the spell's magic. Got it!

This explanation also implies that if I wear a Necklace of Fireballs inside an antimagic field and throw one bead out of the field, it should explode normally. In this case, I am not the origin of any magic; only the magic item is, and once it's outside the antimagic field, nothing stops it from functioning.

If you'll pardon another tangent, I once made a list of spells that have more than one target because they target first the spellcaster and then some other creature, usually one that the spellcaster touches. Here's the list:

Chill Touch
Death Knell
Demand
Dispel Chaos
Dispel Chaos
Dispel Evil
Dispel Good
Dispel Law
Dream
Magic Jar
Sending
Vampiric Touch

4. Finally, I should think about this:


If you are big enough that heads and hands can go outside the area of effect of AMF, then you probably can cast spells. Applying this rule is inherently a DM judgement because the location of heads and hands is abstract…

By my estimation (using the space that a creature normally occupies in combat as a guide):


A creature whose size category is Huge is only 80% protected in an antimagic field.



A creature whose size category is Gargantuan is only 60% protected.



A creature whose size category is Colossal is only 20% protected.

I also believe a very large creature can shift the point of origin of the Antimagic Field to any point on its body. That's what this episode of the Order of the Stick (http://www.giantitp.com/comics/oots0627.html) implies, I think. So the bigger a creature is, the easier it should be for the creature to cast a spell while still protecting part of its body with the Antimagic Field spell.