Our wizard casts Tiny Hut:

Nine creatures of Medium size or smaller can fit inside the dome with you. The spell fails if its area includes a larger creature or more than nine creatures.

My druid is a humanoid when the dome appears around him, but then shapes into a Dire Wolf. He's now a large creature, but wasn't when Tiny Hut had been cast. Does the hut stay or disappear? It's unclear to us whether the "spell failing" refers to the spell being cast or being active?


  • \$\begingroup\$ "Spells and other magical effects can't extend through the dome or be cast through it." If wild shape is considered a magical effect your druid might not even be able to cast it? \$\endgroup\$ Commented Nov 19, 2020 at 13:47
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    \$\begingroup\$ Wild Shape isn't used "through" the dome but inside of it. ;) \$\endgroup\$
    – Vadruk
    Commented Nov 19, 2020 at 20:57

3 Answers 3


The Hut remains.

The common phrasing

the spell fails

refers to a spell's casting. For example, Counterspell reads:

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.

(emphasis mine), Whereas Dispel Magic reads:

Choose one creature, object, or magical effect within range. Any spell of 3rd level or lower on the target ends. For each spell of 4th level or higher on the target, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a successful check, the spell ends.

(emphasis mine). Once a spell is successfully cast in 5e, it's effect doesn't fail; it ends.

This wording is consistent throughout the rules as well. Some spells state circumstances in which they fail (i.e their effects do not take place), and many somehow state circumstances in which their effects end, either through their Duration or explicitly, in the spell effect's description.

A simple example is Call Lightning and the concentration rules (emphasises are mine):

Call Lightning

3rd level Conjuration

Casting time: 1 Action

Range: 120 feet

Components: V, S

Duration: Concentration, up to 10 minutes

A storm cloud appears in the shape of a cylinder that is 10 feet tall with a 60-foot radius, centered on a point you can see within range directly above you. The spell fails if you can't see a point in the air where the storm cloud could appear (for example, if you are in a room that can't accommodate the cloud).


Some spells require you to maintain concentration in order to keep their magic active. If you lose concentration, such a spell ends.


The druid is not squeezed by the tiny hut. Therefore, the Dire Wolfed Druid might poke out of the sphere if there is not enough space for it, making him vulnerable to spells and attacks (albeit with some cover).

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    \$\begingroup\$ I agree with this. I used the same logic in this other question to argue that casting Animate Objects would not collapse the hut due to the sudden presence of 10 additional creatures inside it. \$\endgroup\$ Commented Nov 24, 2020 at 2:33
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    \$\begingroup\$ The one part I'm not sure about is the last bit. If it's just one other person (the caster of the hut) and the druid, there's certainly room for the druid's dire wolf form to squeeze inside the dome. If the druid is one of ten people on the dome, then they're going to have issues fitting. \$\endgroup\$ Commented Nov 24, 2020 at 12:32
  • \$\begingroup\$ You are right for the last bit. I assumed the whole party was in the hut as well. Weather the druid pokes out or not depends on how much space is available ithin the sphere's area. \$\endgroup\$
    – Olivier
    Commented Nov 24, 2020 at 17:19

It's unclear

"The spell fails" really isn't all that clear as to whether it only applies during casting or if it applies whenever something triggers the failure. Because of that, it really becomes a DM decision as to what will happen at the table.

Forming an opinion

As other answers have stated, there are some ways to look at this with other spells, but none of those fully support a single direction for the answer.

You can look at spell failure as a casting issue only. In that case, then anything that makes a currently valid spell invalid would no longer matter.

But that's clearly not always the case. Targets can become invalid if that is so ruled at the table. Invalid targets are an optional rule with Xanathar's, but the idea remains that clearly a spell and target can become invalid and we have to figure out what to do.

Given that the spell has language dictating how many and of what size can creature can be in the hut, it's not unreasonable to rule the spell as invalid if creatures of those numbers or size appear in the hut.

Ultimately, it's up to the DM and table to determine if this makes the spell more powerful using a loophole to bring things in that normally couldn't, or if they want to rule it invalid, or just tell the players they can't do it before it even happens and spells are wasted. Or opt to let it work!


The spell fails if its area includes a larger creature or more than nine creatures.

There is nothing in this sentence to suggest it only applies when the spell is cast rather than throughout its duration. So, if the condition is met at any time, the consequence happens - the spell fails.

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    \$\begingroup\$ "The spell fails" indicates the casting of the spell does not complete. When a spell effect ends after the spell is cast, the rules always use the word "ends". \$\endgroup\$ Commented Nov 18, 2020 at 22:31
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    \$\begingroup\$ @ThomasMarkov Language in other spells seem to indicate that the 'failing' is more at time of casting, but it doesn't mean it doesn't complete. Most of those the spell does complete (action/resource lost), but does not successfully provide the effects. While this can be read as one of those, it's also not unreasonable to extend it to if you make the spell invalid by introduces things that would force it to fail, then it fails. \$\endgroup\$
    – NotArch
    Commented Nov 19, 2020 at 17:18

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