Monday, August 25, 2014

Spells Through The Ages – Antimagic Shell

Antimagic shell has been in the game ever since Chainmail Fantasy. It's another one of those high-level spells that I haven't seen get used much (in fact: never), because despite its obvious power, it seems to cancel out the very thing that makes the wizard casting it special: his or her own spells. Let's consider it:

Chainmail Fantasy

Anti-Magic Shell: This causes a bubble of force to surround the user and totally prevents anything magical from either entering or leaving the shell. It lasts for up to six turns. Shell radius is 5". (Complexity 6)

Notice that the name is actually hyphenated, which is retained up through 2E. Now, some important stuff which will contrast with what comes later: First, it says that magic is prevented from "entering or leaving" the shell; narrowly read, this leaves normal operations inside the shell, such that the wizard can continue casting spells within (e.g., protective spells or items, conjuring an elemental, teleporting away to safety, etc.), seemingly giving more options for the wizard in question. Also, this seems to be in tune with the unique naming of the magic as a "Shell", which seems to imply a barrier defense, with some different content inside. Was that the original intent? Secondly, notice the rather enormous area of effect: 5" radius (which depending on how you interpret that might be 50 feet radius, although I assess it at 25 feet radius in man-to-man scale); this will be greatly reduced in later editions.

Original D&D

Anti-Magic Shell: A field which surrounds the Magic-User and makes him totally impervious to all spells. It also prevents any spells from being sent through the shell by the Magic-User who conjured it. Duration: 12 turns.

Largely the same as in Chainmail, but note some fine details. The description has changed from a "bubble" to a "field" (which in physics "occupies space"; link), and makes the caster "totally impervious to all spells", possibly even inside the shell (e.g., an enemy caster that walked into the shell couldn't cast spells within the barrier)? Also, the wording has switched from preventing "anything magical" to "any spells", which might arguably be more limited (magic swords, et. al.?), but is probably not the intent. Finally, no area of effect is given: note that it's a common Gygaxianism to leave out some of the most important details like that when advancing editions (generally still presuming familiarity and use of the prior work).

Swords & Spells

Anti-Magic Shell: [Range] touch, [Area of Effect] 1", [Turn Duration] 12.

In Swords & Spells, Gygax gives the antimagic shell an area of 1", filling in the gap in OD&D, and much smaller than that seen in Chainmail. This actually might be my favorite and simplest specification for the area, but no other edition will use it. Recall that the range "touch" here is used for all caster-only spells (c.f. polymorph self and so forth).

D&D Expert Rules

Anti-Magic Shell 
Range: 0' (caster only)
Duration: 12 turns

This spell creates a personal barrier about the caster that stops any magic spell or spell effect from coming in or going out. It blocks all spells (including the caster's) until the duration is up or until the caster decides to end the spell.

If we look at this with a magnifying glass, it has some bits of understanding from both the prior editions ("any magic spell or spell effect from coming in or going out"). However, Cook makes it a "personal barrier" (Range: 0', caster only), which is pretty likely how you'd interpret the OD&D text with no listed area, if you weren't also looking at Chainmail at the same time.

AD&D 1st Ed.

Anti-Magic Shell (Abjuration)
Level: 6

Range: 0
Duration: 1 turn/leve1
Area of Effect: 1'/level diameter sphere

Explanation/Description: By means of an anti-magic shell, the magic-user causes an invisible barrier to surround his or her person, and this moves with the spell caster. This barrier is totally impervious to all magic and magic spell effects (this includes such attack forms as breath weapons, gaze weapons, and voice weapons). It thus prevents the entrance of spells or their effects, and it likewise prevents the function of any magical items or spells within its confines. It prevents the entrance of charmed, summoned, and conjured creatures. However, normal creatures (assume a normal troll rather than one conjured up, for instance) can pass through the shell, as can normal missiles. While a magic sword would not function magically within the shell, it would still be a sword.

That's the PHB text, here's the DMG errata:
Anti-Magic Shell: It must be pointed out that creatures on their own plane are normal creatures, so this spell cost upon the Elemental Plane of Fire, for example, would hedge out none of the creatures of the plane.

Now, this version has several changes. It returns an area of effect based on caster level (at least about 12' diameter, so you can probably fit in several friends). It is the first one totally explicit that magic is disrupted "within its confines". The effect also includes defense against breath, gaze, and voice weapon; charmed, summoned, and conjured creatures; and also the effects of magic swords and the like. However, these newly called-out defenses create some possible interpretive problems: If a magic arrow is shot at the shell, does it shatter, disappear, or turn into a normal missile? If the caster moves aggressively against a summoned monster, what happens then? What if a charmed creature gets thrown through the air at the shell, does it physically bounce off or something else?

AD&D 2nd Ed.

Antimagic Shell
Range: 0

Duration: 1 turn/level
Area of Effect: 1 ft./level diameter

By means of this spell, the wizard surrounds himself with an invisible barrier that moves with him. The space within this barrier is totally impervious to all magic and magical spell effects, thus preventing the passage of spells or their effects. Likewise, it prevents the functioning of any magical items or spells within its confines. The area is also impervious to breath weapons, gaze or voice attacks, and similar special attack forms.

The antimagic shell also hedges out charmed, summoned, or conjured creatures. It cannot, however, be forced against any creature that it would keep at bay; any attempt to do so creates a discernible pressure against the barrier, and continued pressure will break the spell. Normal creatures (a normally encountered troll rather than a conjured one, for instance) can enter the area, as can normal missiles. Furthermore, while a magical sword does not function magically within the area, it is still a sword. Note that creatures on their home plane are normal creatures there. Thus, on the Elemental Plane of Fire, a randomly encountered fire elemental cannot be kept at bay by this spell. Artifacts, relics, and creatures of demigod or higher status are unaffected by mortal magic such as this.

Should the caster be larger than the area enclosed by the barrier, parts of his person may be considered exposed, at the DM's option. A dispel magic spell does not remove the spell; the caster can end it upon command.

This is basically identical to 1E, and folds in the note from the DMG as is customary. The name is finally changed to remove the hyphen. It tries to solve the problem of "what happens when the caster attacks a magical creature?", by creating a "discernible pressure" that might break the spell -- personally, that seems a bit clunky and tone-deaf in how an immaterial field of non-magic can create physical pressure on the caster. There is also an added paragraph at the end that introduces two new details: (1) large creatures may or may not be partly exposed when casting the spell (a maybe-or-maybe-not 2E-ism), and (2) dispel magic cannot remove an antimagic shell. Is that a good idea? Does antimagic serve to cancel other antimagic?

D&D 3rd Ed.

Antimagic Field
Level: Clr 8, Magic 6, Protection 6, Sor/Wiz 6
Components: V, S, M/DF
Casting Time: 1 action
Range: 10 ft.
Area: 10-ft.-radius emanation, centered on the character
Duration: 10 minutes/level (D)
Saving Throw: None
Spell Resistance: See text

An invisible barrier surrounds the character and moves with the character. 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. Golems and other magical constructs, elementals, outsiders, and corporeal undead, still function in an antimagic area (though the antimagic area suppresses their supernatural, spell-like, and spell abilities normally). If such creatures are summoned or conjured, however, see below.

Summoned or conjured creatures of any type and incorporeal undead wink out if they enter an antimagic field. They reappear in the same spot once the field goes away. Time spent winked out counts normally against the duration of the conjuration that's maintaining the creature. If the character casts antimagic field in an area occupied by a conjured creature who has spell resistance, the character must make a caster level check (1d20 + caster level) against the creature's SR to make it wink out.

Normal creatures can enter the area, as can normal missiles. The spell has no effect on constructs that are imbued with magic during their creation process and are thereafter self-supporting (unless they have been summoned, in which case they are treated like any other summoned creatures). Undead and outsiders are likewise unaffected unless summoned. These creatures' spell-like or supernatural abilities, however, may be temporarily nullified by the field.

Dispel magic does not remove the field. Two or more antimagic fields sharing any of the same space have no effect on each other. Certain spells remain unaffected by antimagic field (see the individual spell descriptions). Artifacts and creatures of demigod or higher status are unaffected.

Note: Should the character be larger than the area enclosed by the barrier, any part of the character's person that lies outside the barrier is unaffected by the field.

3E changes the name from antimagic shell to antimagic field, borrowing from the text description back in OD&D, and aligning the name with the fact that it's antimagic throughout the volume of space (which was possibly not the case back in Chainmail, but that can be argued). There is additional detail given to the fact that spells get suppressed but their duration clock keeps ticking, and that summoned, conjured, and incorporeal undead "wink out" if they come in contact with the sphere, reappearing later on -- which to me seems even more kindergarten-y and deaf to the literature. Charmed creatures are no longer specifically called out, although I think we can conclude that the creature can pass into the sphere but the charm is then lifted at the time. 3E keeps the no-dispel rule, answers the antimagic-vs-antimagic question (they can overlap with no effect), and also settles the large-creature issue (definitely partly exposed, which seems very strange).

Also this addresses another issue that I'm surprised didn't come earlier: What about golems and similar constructs, who are created by magic, but whose essential power is that they're immune to all magic by default? 3E answers in that they are not affected in any way; an iron golem can waltz in and brain your wizard just like he normally can, a possibly strange ruling, but generally consistent from the point-of-view of the golem's ignoring of most types of spells. Does that seem correct to you?


While it's possible to read the Chainmail description as a true "shell" (surface barrier only), such that the wizard can still be casting personal magic inside, this clearly gets ruled out in later editions. As I mentioned above, this has always seemed partly troubling, for what does the D&D wizard have but his spells? In this respect the AD&D spell globe of invulnerability seems seems like a better option, possibly a direct response, in that spells go out but they don't come in (up to a certain level).

In later editions, the effect of antimagic shell was expanded (or further fleshed out) to ban exotic attacks like breath, gaze, summonses, and conjured creatures, but the corner-cases of exactly what happens when those creatures touch or get touched by the sphere caused ongoing complications that seem indelicately resolved (not uncommon in powers initially designed as defenses that get turned around by players for offensive purposes). Note that in theory, even something like the 1st-level protection from evil might have the same issue ("keep out attacks from enchanted monsters", OD&D), but that spell never found need to add the same complications that antimagic shell did.

I might go so far as to ask: What's so critical about disallowing that anyway? Might we not run antimagic shell by allowing the caster to move into range of a conjured elemental or invisible stalker and actually disrupt their presence? That would make for some legitimately potent use from this otherwise questionable spell, and the wizard would need to balance the risk in that they have no choice but to walk out onto the field of battle, with absolutely no other defenses active in order to make it happen (by virtue of the non-magic effect, of course). It could be used in magic-trap-sweeping capacity, as well (otherwise not prohibited in any edition).

Other questions: Do you see the spell get used much in your games? In what tactical situations does it get used? Would it be a better option if the casting wizard could still use personal magic inside the shell? And what's your preference for the effect it has when contacting summoned, conjured, charmed, or magically constructed monsters?


  1. I have only ever seen Anti-Magic of any kind used as DM fiat. I wonder if that is not how this spell came to be.
    Of course, we rarely got to high enough level for a lot of this stuff.
    If we keep it as a personal/extremely close range spell then I think we should go back to the "shell" interpretation.
    It can act as a barrier for summoned/conjured/charmed creatures.
    Golems etc I would give a pass. I always looked at them as "Instantaneous" magic over "Permanent" magic, meaning once the creation is complete, they simply "are". But that is a whole other discussion.

  2. Anti-magic shell was never used (that I can remember) in my old campaigns due to the plethora of more useful spells at 6th level: control weather, death, disintegrate, flesh-to-stone (and its reverse), reincarnation...all took precedence over AM shell.

    Part of this had to do with the nature of the challenges for characters at high level: encounters with big-ass monsters need spells that can take 'em down fast. If you have secondary consideration, it's for recovery of the party cleric (reincarnation, stone-to-flesh) to keep the party going. High level MUs (the thing against which AM shell defends) aren't as dangerous as one might fear because A) high level PCs have the HPs to absorb damage spells, and the god saves to resist "auto-kill" spells, and B) enemy MUs are still vulnerable to the fighter melee attack (magic weapons and high attacks = disrupted spells and a quick-dying mage).

    As with some other spells (notably “cacodaemon”), anti-magic shell would appear to be more useful/appropriate as a lower level spell. I didn’t bother to include it (nor a facsimile) in my Five Ancient Kingdoms game.

    Anti-magic shell makes much more sense in the game of Chainmail. In terms of tabletop wargaming, being able to throw up a 5” shell (in other words, a globe) that prevents all magic from entering its diameter is pretty useful…especially as wizards in Chainmail can cast an unlimited number of auto-kill fireballs and lightning bolts that have a line-o-sight range. In a way, it’s an ability to manipulate terrain during the game (creating a barrier that blocks magical effects), much as hallucinatory terrain can be used to block line-o-sight archers, and cloudkill creates a “terrain piece” that can assault troops. The complexity levels reflect this: hallucinatory terrain only lasts till someone touches it (complexity 4) whereas actually moving terrain (permanently changing the tabletop) is complexity 6…which, like anti-magic shell, requires a wizard to roll a “9” (on 2D6) to successfully cast.

    On a related note, I’ve always found the beholder’s “anti-magic ray” (in AD&D 1E) the most difficult thing to understand and rule on. Where’s the explanation for THAT?

    1. This pretty much matches my experience, too. Only useful in specialized or contrived situations. If you could protect a whole troop of elite warriors in Chainmail, then that's a pretty neat combo. Maybe best on a scroll in the D&D context?

  3. We used it in 3rd edition a couple times when fighting beholders. The fighter types could take the beholders down without worrying about disintegrate, and the wizards positioned somewhere else, could take down his minions with spells. In this case it was a Cleric that cast it on himself, not a wizard. 3rd edition lists a range, so it seems like you could cast it on your fighter, or directly on the thing you want to take the magic from.

    As a wizard self only kind of spell, it would not be as useful, although, in many parties when facing a beholder it still might be a good trade to lose your magic, to make the beholder lose his magic. It never occurred to me before, but the same would be true of most level draining undead (assuming the requirement of having a magic weapon to hurt the undead would be suppressed as well, or you just made them invulnerable)

    I think I like the concept of an actual shell best. Spells abilities work inside, but can’t cross. That sounds best to me, but could be hard to make work out. What happens to magical weapons, can they cross, if no, does that mean anyone carrying any magic items can’t cross the shell, etc etc etc?

    All in all, I like the shell best, but think the 3rd edition rule is the most workable.

    1. By-the-book, I really don't think even the 3E version is intended to allow the spell to be cast on anyone else. That would require a "target" specifier (like in protection from evil, etc.) The book text actually is phrased as "An invisible barrier surrounds you and moves with you..." (3E PHB p. 175), where "you" is always used there from the perspective of the caster. The fact that it has both "range" and "area" is just a bit of a mangled specification, I think.

      So based on that, we're back to caster-only in all editions, and I fully agree it seems really hard to make that work in most cases.

    2. I think you are right. We had our Cleric cast it on himself, I think other people in the party may have understood it as self only.

      I hate the way they list those ranges. It is similar to lightning bolt which has a range of 120' and an area of effect of 120' line. In reality the range is 0, I don't know why the add the effect size to the range. Fireball does not say Long + 20'. As long as I'm ranting I'm not sure why it does not say Target: self only.

    3. I totally agree, their usage of those specifiers is highly confusing. Although, now that I think of it: 3E has this rule that "If any portion of the spell's area would extend beyond the range, that area is wasted" (PHB p. 148). So that obligates them to set a range at least equal to the area for all spells, or else technically they'd get cut off. And compared to earlier editions that makes the entries really confusing to read -- I think that was a really cruddy rule to include in 3E.

  4. Closest I've gotten is Otiluke's Spheres, in actual play.

    I agree that the 3E version seems to offer the most utility. (I'd also say the "winking out" thing, rather than being "kindergarteny," has interesting implications for how summoning works and what it means.) The fact that you can cast it on someone else within 10' alone means its major weakness can be easily avoided: just cast it on a more martial character and send them in to take down any enemy spellcasters.

    1. See above; I really don't think the 3E language allows casting it on someone else. It doesn't have a "target" line, and the book text is all in reference to the effect on "you" (the caster).

  5. AMS only appeared in Chainmail after D&D had come out; that is, as of 3rd edition Chainmail (1975). So the OD&D usage should be first, with the Chainmail Fantasy version coming second.

    Chainmail 2nd (1972) has only eight spells, ten if we count the default "Fireball" and "Lightning Bolt." Chainmail 3rd doubled the list and radically changed the spell system, introducing "complexity" and many other concepts.

    1. @ Jon:

      Ah...I must have a later edition of Chainmail. Still, it seems an odd spell for a non-wargame. I wonder what was the inspiration for the spell.

    2. Hey Jon, thanks for that. I do have Chainmail 3rd Edition (7th printing, April 1979), so I'm always guessing as to what was in the earlier editions. Is there a listing somewhere of the original 8 magic spells in fantasy Chainmail (so I don't keep making this mistake)?

      Although it seems extremely curious why the CM version would get that large area (5") and short duration which is out-of-sych with all the other editions, if it came after OD&D.

  6. Some more uses from comments in a thread in Facebook. Perhaps the best interpretation is to look at it as a team-combo spell, protecting the party's fighters (not just the wizard alone), somewhat as seen with Chainmail's large area-of-effect. Possibly best on a scroll.

    - General protection spell if you run into a monster with a powerful breath weapon, gaze, etc.
    - High-level magical trap protection (e.g., Tomb of Horrors)
    - For multiclass fighter-wizards engaging in melee (except that the canonical case, elves, aren't allowed high enough level to use it any of 0E-BX-1E).
    - Fighting any magical creatures, making a "base" and allowing companion fighters to shoot or fight out of (incl. narrow corridor with ranged attacks).
    - Locking down an enemy wizard before they can teleport away and letting companion fighters beat on them.