This is based on a situation that's happening in my current campaign, though the example below is simplified to remove unnecessary context.

The shapechange spell (Player's Handbook, page 274) only limits the form that its user can change into by Challenge Rating, rather than size.

In the following situation, how, if at all, would shapechange be suppressed?

A level 20 wizard and a level 20 druid stand with 10 feet of space between them (figure 1).

To begin their battle, the druid casts shapechange, transforming into an ancient brass dragon, a Gargantuan creature (figure 2).

To counteract this, the wizard casts antimagic field (Player's Handbook, page 213) which creates a field of anti-magic in a 10-foot radius sphere around the wizard within

"Spells and other magical effects, except those created by an artifact or a deity, are suppressed in the sphere and can't protrude into it."

It seems clear-cut that shapechange is suppressed until the druid exits the antimagic field, and so reverts to its normal, medium form (figure 4).

Now the druid's smaller, Medium form, is no longer within the antimagic sphere. So it should regain the effects of shapechange, transforming back into an ancient brass dragon—which immediately puts its form back into the antimagic field, repeating the process. If it were another buff spell, such as fire shield (Player's Handbook, page 242), that doesn't affect the target's size, this would be a nonissue. But shapechange, along with enlarge/reduce (Player's Handbook, page 237), polymorph (Player's Handbook, page 266), and any other spell that might increase the target's size run into this issue. enter image description here

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    \$\begingroup\$ Why cant the druid's position adjust due to the field? Why would the original starting position still be it? Could the druid not be forced into one of the fields squares since he is being affected by the field? \$\endgroup\$
    – Fering
    Commented Jun 13, 2021 at 15:49
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    \$\begingroup\$ That's one possible resolution that I've considered! That could be a question all its own, really—"In which space on a grid does a Medium creature appear after an effect that transformed it into a Large or larger one ends?" So I hesitate to use that as a quick and easy solution. \$\endgroup\$
    – user55434
    Commented Jun 13, 2021 at 15:51
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    \$\begingroup\$ @Fering That sounds like the start of a good answer. Related to that, we do have the following question: "When a druid reverts to their normal form having wild shaped into a Large beast, can they choose which square they occupy?" \$\endgroup\$ Commented Jun 13, 2021 at 15:59
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    \$\begingroup\$ The druid has better not fallen asleep as a brass dragon near the edge of the cliff. Once the spell is done ... splatt! \$\endgroup\$ Commented Jun 14, 2021 at 13:22

6 Answers 6


If you maintain creature positions, the effect is simply suppressed and the druid remains in its typical form

The druid can't take the Brass Dragon form when some portion of that form would intersect the region affected by the anti-magic field. The order of events, as described in the question, is as follows:

  1. The druid changes into the dragon
  2. The druid-as-dragon moves such that part of its body enters the anti-magic area (or is already in an area which causes part of its body to be in the anti-magic field's area of effect when it is created)
  3. The anti-magic effect immediately ends the transformation, reverting the druid to its normal form
  4. The druid, as a medium-sized creature, is no longer in the zone affected by the magic suppression, and so the suppressed effect stops being suppressed and the druid resumes dragon form
  5. As no movement has occurred, the dragon's form once again intersects the anti-magic field, and the effect is suppressed again
  6. Repeat ad infinitum

I submit that there is a breakdown between steps 3 and 4. The effects of shape-changing spells are immediate and there is no time spent in the transformation (by RAW; cool narration may differ). So the transformations don't take up any time. But the Brass Dragon form cannot persist here, as the anti-magic effect prohibits it. Meanwhile the druid form can persist here.

Even if you favor an infinite loop of transforming back and forth, the druid cannot spend any time in dragon form here. But if time still passes, as over the course of a turn, the druid must have some form, and if it can't be the dragon it must be the druid. Therefore, as long as the larger, shapeshifted form would intersect the anti-magic field and immediately suppress the effect, the transformation cannot occur/cannot persist in time. The only form the druid can be in is one which does not enter the anti-magic field.

This is in line with a (somewhat but not exactly) analogous limitation described by Enlarge/Reduce:

If there isn't enough room for the target to double its size, the creature or object attains the maximum possible size in the space available. (PHB, Chapter 11: Spells, Spell Descriptions, Enlarge/Reduce)

You can only become as big as the space allows. The anti-magic is, in effect, a limitation on how large a creature could become. As shapechanging doesn't allow for dynamic sizing, the druid cannot be in its shapechanged form as long as the anti-magic effect would interfere.

  • \$\begingroup\$ I don't think this is "The order of events, as described in the question," specifically your step 2. In the question, it is the casting of the antimagic field that impacts the druid's form, not the druid's movement. In the OP's question, the druid does not move - they begin and end 10 feet from the wizard. \$\endgroup\$
    – Kirt
    Commented Jun 14, 2021 at 13:46
  • \$\begingroup\$ @Kirt I see what you're saying and expanded, but I'm missing it if there is a material difference. The key element is that there is no movement once the anti-magic field is intersected. My brain is still spinning up for the day-- am I missing something significant? \$\endgroup\$
    – Upper_Case
    Commented Jun 14, 2021 at 15:09
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    \$\begingroup\$ I don't think there is a material difference in what would happen, it was just that your answer, as written, did not faithfully describe the sequence as proposed by the OP. Your edit now includes that as a possibility. \$\endgroup\$
    – Kirt
    Commented Jun 14, 2021 at 15:23
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    \$\begingroup\$ @Kirt You were correct and I tried to address it, but I wanted to make sure I was getting all of it. Thanks! \$\endgroup\$
    – Upper_Case
    Commented Jun 14, 2021 at 15:35

Space permitting, the druid decides

It is essential to understand that just because an ancient brass dragon is Gargantuan, does not mean that it occupies the entirety of a 20' x 20' square. Rather, DMG Chapter 12 (Monsters) says:

Size. The Size Categories table shows how much space a creature of a particular size controls in combat...

and PHB Chapter 9 (Combat) says

Creature Size. Each creature takes up a different amount of space. The Size Categories table shows how much space a creature of a particular size controls in combat...

Space. A creature's space is the area in feet that it effectively controls in combat, not an expression of its physical dimensions. A typical Medium creature isn't 5 feet wide, for example, but it does control a space that wide...A creature's space also reflects the area it needs to fight effectively...

Squeezing into a smaller space. A creature can squeeze through a space that is large enough for a creature one size smaller than it...While squeezing through a space, a creature must spend 1 extra foot for every foot it moves there, and it has disadvantage on attack rolls and Dexterity saving throws. Attack rolls against the creature have advantage while it's in the smaller space.

Thus, one simple resolution is to reposition the body of the dragon such that the entirety of its physical form is outside of the antimagic field (without actually moving it - this is an absolute reduction in squares occupied, not a shift in squares). The druid would be permitted to retain the form of a dragon, but would not be permitted to control any space in which the field covered more than half the square. At the discretion of the DM, if this sufficiently restricted the area available to the dragon, it would also be subject to the squeezing condition.

The DM could rule that this simply happens per force to the positioning of the dragon, similar to other shape change effects that automatically take account of environmental circumstances. Or, the DM could allow the player of the druid to decide, and give them the choice: "In response to the antimagic field, you can adjust your positioning to retain your shape as a dragon. If you choose not to, you will resume your shape as a druid until such time as you can move further away from the field." I would suggest the latter, since as a DM I try to give players more choices and more autonomy.

Some might object that the druid could not adjust their position when it is not their turn. I consider this analogous to the standard condition of changes of facing being free even when it is not one's turn, being able to use a shield to defend against attacks from any direction, etc. (basically everything that is allowed when one is not using the optional facing rules from DMG 252)

To sum up, when the dragon is affected by the antimagic, we can assume that the dragon form is maintained, but in a smaller number of spaces. Only when the dragon itself no longer fits in the spaces available is it forced to revert to the druid.

The OP asks for the "best" way to resolve this paradox, but has neither put forth criteria for what the best resolution would be, nor had their question closed as opinion-based. I offer the following as recommendations for my answer:

(1) It is fun in that it allows both the shapechange and antimagic field spells to still be, at least partially, in effect. For both players it allows meaningful choices.

(2) It is fair in that it allows the antimagic field spell to impose limitations and disadvantageous conditions on the shapechange spell since it was chosen specifically to do that

(3) It is rules-based in that the restrictions imposed on the dragon shape are grounded in RAW for size, position, and squeezing

(4) It is quick in that the initial decision of what happens is based on a single assessment of the DM and then a possible decision by the player of the druid, rather than perpetuating a state of infinitely repeating transformations.

(5) It is tactical in that both players can use their positioning to further change the situation, but such changes are simple to resolve.

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    \$\begingroup\$ I like this solution, but I think the answer can be improved by summing up in plainer language somewhere \$\endgroup\$ Commented Jun 14, 2021 at 14:46
  • \$\begingroup\$ @aherocalledFrog better? \$\endgroup\$
    – Kirt
    Commented Jun 14, 2021 at 15:29

While not intended, it seems my comment is more of an answer than expected, so I will formalize it herein.

In order to prevent this paradox, despite the original location having two empty squares between the druid and wizard, when returning to medium sized any square that was occupied by the druid becomes fair game. Since there is an effect causing it to be suppressed instead of dismissed/cancelled/countered, it would make the most sense for the medium sized square to be within the space of the effect that is suppressing the larger size. Otherwise depending on how your group handles increasing/decreasing size, you end up growing once no longer suppressed, and then shrinking again if you ended up back within the effect.

When it comes to increasing size, my groups have always allowed the player to grow as they see fit so long as their original square(s) is contained entirely within the new form's space.


The rules have no guidance, and yoyoing between forms forever doesn’t make sense, so just pick a position for the Druid that makes sense.

The rules don’t tell us what to do here, unfortunately. But in my experience, infinite loops are probably wrong, so we need to just make a ruling that does not result in the Druid yoyoing between forms because of entering and exiting the antimagic field repeatedly. So just position the Druid so that we don’t have that happening. The best way to resolve it is any way that moves combat forward.


The spell is partially suppressed.

Spells overlapping with an antimagic field are only suppressed where they overlap with the antimagic field. Outside the antimagic field, the druid is a dragon; inside the antimagic field, the druid is a Medium creature.

With the specific positioning described, that means only the dragon exists (i.e. only the dragon form can be targeted by attacks), but the dragon's body ends where the antimagic field begins; so the dragon can't take any actions that would involve physically touching things inside the antimagic field. Any attempt to reach inside the antimagic field and touch things (i.e. perform a melee attack) should be done using the druid's true form.

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    \$\begingroup\$ Kudos for the interesting solution, even if it isn't one I would personally pick! \$\endgroup\$
    – TylerH
    Commented Jun 15, 2021 at 19:11
  • \$\begingroup\$ This is exactly how I'd play it. I think it would be a. hilarious to just have the dragon form cease to be at the edge of the sphere (and depending on my players I might have fun describing the cross-section of dragon innards that was being shown right at the edge of the field and b. effectively conveying both the "mundane" vibe of an antimagic field and the fantastical aspect of the magic itself. \$\endgroup\$
    – webnesto
    Commented Jun 18, 2021 at 20:13

Typically when something finds itself inside a magical area whose description/rules state that the thing "cannot exist" there, the thing is ejected or forcibly moved (see Mordenkainen's Magnificent Mansion, Passwall, the Genie Warlock's Sanctuary Vessel ability, Watery Sphere, Wall of Stone, Wall of Force, and so on).

So in this ruling, the Druid retains their Ancient Brass Dragon shape, but is physically pushed back/ejected from the sphere.

You could afford the player more agency (usually a good idea in D&D) by giving them the choice—as discussed in other answers already—of whether they want to allow the Ancient Brass Dragon form to be dropped while remaining in the edge of the Anti-Magic sphere as their new position, or be pushed out of the sphere and retain the Ancient Brass Dragon shape.

  • \$\begingroup\$ Choosing to be pushed away every time the wizard moves closer seems like it grants the druid an undue advantage. The wizard does need to be able to close the distance and force the druid out of its shapeshift if desired. \$\endgroup\$
    – Brilliand
    Commented Jun 15, 2021 at 19:20
  • \$\begingroup\$ @Brilliand If we are concerned about having a fair/balanced arena match or one where you want the wizard to have the advantage, perhaps, but in the "real world of D&D", such concerns of fairness are unnecessary... encounters are gonna happen in an unbalanced way sometimes. In short, the wizard needs to pick a different spell, or cast walls of stone (or similar) first to box the opponent in and then use the anti-magic sphere to basically pin the dragon up against a surface it can't be pushed through, causing it to enter the sphere and be nullified. \$\endgroup\$
    – TylerH
    Commented Jun 15, 2021 at 20:04
  • \$\begingroup\$ Pick a different spell? He's using frikkin' Antimagic Field! To counteract the effects of a spell! What's supposed to be the "better" version of it? An upcast Dispel Magic? \$\endgroup\$
    – Brilliand
    Commented Jun 15, 2021 at 22:12
  • \$\begingroup\$ @Brilliand I mean what's the goal? Anti-magic field doesn't hurt people, and it also only affects 5 feet in any direction of you. \$\endgroup\$
    – TylerH
    Commented Jun 16, 2021 at 0:29
  • \$\begingroup\$ You want a spell suppressed, so you cast Antimagic Field and walk within 5 feet of it... seems like a pretty standard use to me. The advantage of this over Dispel Magic is that you can do it every turn off of just one spell slot, even if the caster of the spell is present and willing to keep recasting it. \$\endgroup\$
    – Brilliand
    Commented Jun 16, 2021 at 19:37

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