I am having issues finding this answer and so I was wondering if someone here could help me, is my interpretation correct here?

In a fight with some monsters, Cloudkill was cast by one of them, this caused some issues that one player tried to resolve using Gust - a cantrip. I made the ruling that:

Gust could not undo the Cloudkill, but it could influence its direction.

I feel this was a good middle ground as Gust is a cantrip and Cloudkill is a 5th level spell. With the description in Cloudkill stating:

It lasts for the duration or until strong wind disperses the fog, ending the spell.

Whilst Gust does not state 'Strong Wind' (only implies it), the spell Gust of Wind, does state:

A line of strong wind

I feel I am correct Rules as Written when it comes to Gust & Cloudkill, but I have been wrong many times before.

  • 1
    \$\begingroup\$ Minor aside, but Gust of Wind takes at LEAST 4 rounds to disperse Cloudkill. GoW is 10' wide, and Cloudkill is 40'. A wizard proactively clearing the area around an ally might take longer than 4 rounds to clear it all away but gosh would that be a PITA to adjudicate. \$\endgroup\$
    – aslum
    Mar 19 at 17:07

3 Answers 3


No, Gust cannot affect Cloudkill for several reasons.

First of all, recall that strong wind is a game term, defined in the DM, page 110:

A strong wind imposes disadvantage on ranged weapon attack rolls and Wisdom (Perception) checks that rely on hearing. A strong wind also extinguishes open flames, disperses fog, and makes flying by nonmagical means nearly impossible. A flying creature in a strong wind must land at the end of its turn or fall. A strong wind in a desert can create a sandstorm that imposes disadvantage on Wisdom (Perception) checks that rely on sight.

Hence, "strong wind" is a game term linked to precise effects: in case one needs a numerical definition, it can be found in other spells. The description of Stinking Cloud says:

A moderate wind (at least 10 miles per hour) disperses the cloud after 4 rounds. A strong wind (at least 20 miles per hour) disperses it after 1 round.

And this numerical characterization is consistent1 with the one in Storm of Vengeance:

Finally, gusts of strong wind (ranging from 20 to 50 miles per hour) automatically disperse fog, mists, and similar phenomena in the area, whether mundane or magical.

Then, when Cloudkill's description specifies that a strong wind can disperse the fog, it means that some game feature have to create such precise effect for dispersing it.

Moreover, the fog created by Cloudkill is heavier than air:

The fog moves 10 feet away from you at the start of each of your turns, rolling along the surface of the ground. The vapors, being heavier than air, sink to the lowest level of the land, even pouring down openings.

So, even 2 effects of Gust are capable to move objects or creatures, nothing in this spell allows to influence the movement of Cloudkill's fog (recall that the fog is not an object): such fog moves only 10 ft per round from the caster per description, that's it.

Of course, as a DM, one could rule that, since Gust can move creatures or objects, it can influence the movement of the fog or just create a small area of "safety", but this is an overruling, allowed by the Rule 0.

For comparison, as noted in the question, Gust of Wind produces exactly strong wind, hence it can disperse the fog and then it ends the spell. There are several spells that produce strong wind: Control Weather, Storm of Vengeance, Wind Wall.

1 Even the definition of moderate wind is consistent: check the Incendiary Cloud spell.

  • \$\begingroup\$ In addition to the DMG quote you provide, a "strong wind" is simultaneously defined as being 20+ mph in the description of a smoke grenade (DMG 268), but as 21 mph or more in the description of an eversmoking bottle (DMG 168). \$\endgroup\$
    – Kirt
    Mar 21 at 16:55


Gust cannot affect Cloudkill in any way.

It lasts for the duration or until strong wind disperses the fog

Gust can:

  • possibly push a creature 5 feet
  • move a small object
  • create a harmless sensory effect

None of those create a strong wind that can disperse fog.

  • 2
    \$\begingroup\$ Also the Gust of Wind spell quoted in the answer is a different, level 2 spell. Gust itself has no language about creating a strong wind. \$\endgroup\$ Mar 19 at 6:38
  • \$\begingroup\$ @NobodytheHobgoblin it can "create a small blast of air". Apparently, this blast is not strong enough. \$\endgroup\$
    – enkryptor
    Mar 19 at 8:10
  • 3
    \$\begingroup\$ @enkryptor Strong wind is a defined game term. \$\endgroup\$
    – Eddymage
    Mar 19 at 8:39
  • 6
    \$\begingroup\$ While I don't think gust should disperse fog from a game mechanics standpoint, realistically any wind that's strong enough to move an actual person 5 feet should be able to push a cloud of vapor. \$\endgroup\$
    – smbailey
    Mar 19 at 22:16
  • 2
    \$\begingroup\$ @smbailey why? I can push an actual person 5 feet no troubles, but I can’t disperse fog. \$\endgroup\$
    – Dale M
    Mar 20 at 2:56

Gust can't counter, nor can it disperse the cloudkill.

As the other answers explain in detail, the description of cloudkill says that it is dispersed by a "strong wind". A "strong wind" is a game term defined in the PHB and DMG as a wind of 20+ mph (or 21+ mph in some sources). The gust spell, in contrast, says only that it creates a "small blast of air" and neither gives us the speed of the air 1 nor characterizes it as "strong". Spells do what they say they do, and nothing in gust says that it creates a strong wind.

But can gust affect the cloud in any way?

The description of gust describes how it affects objects (not heavier than five pounds; does push one ten feet) and creatures (not larger than Medium; could push one five feet). We know how gust affects these things and can be confident about objectively applying these effects.

But the gas from a cloudkill is neither an object, nor a creature - it is a spell effect. We aren't told how gust might interact with a spell effect. Nor, for that matter, are we told how it would interact with other game entities that are not creatures or objects, like a building, vehicle, spirit or trap.

However, we are given some guidance in the form of gust's third line:

You create a harmless sensory effect using air, such as causing leaves to rustle, wind to slam shutters shut, or your clothing to ripple in a breeze.

The "such as" alerts us to the fact that these are all examples of how gust interacts with things that are not of the first two categories (where the interactions are better defined). They are examples, but not an exhaustive list. Individual leaves are objects, but the gust spell itself can only translocate a single object, not multiple leaves (they rustle in place, instead of moving to a new spot). Shutters are not objects; rather they are parts of a building - they can be slammed, but not ripped off their hinges. Worn clothes are objects, but they are not "neither held nor carried" and can thus be rippled but not carried away.

So what are the bounds of these interactions? We are told that they need to be a "harmless sensory" effect (and note that the same phrase is used in prestidigitation). "Harmless" means they shouldn't be able to cause damage, of course - I can't use the gust spell to launch an object at a creature (it is not the catapult spell). I would interpret "harmless" further as meaning they can't impair another creature - I can't use gust to, for example, temporarily blind a creature with a puff of air in its eyes or distract it enough to force a Concentration save. "Sensory", however, means it can be detected by one's senses - whatever I do with gust, it is noticeable. Thus it is strong enough to be seen, felt, and heard - but not so strong that it can impair.

So, given these examples and parameters, suppose I have a player that wants to use gust to cause ripples on the surface of a pond. If I focus only on the first two lines of gust, I might say "well, pond water is neither a creature nor an object, so gust can't affect it." But if I apply the third line, is causing ripples on the surface of the pond a harmless sensory effect? The force of the wind (sensation of touch) creates movement in the water, but that movement doesn't harm anything, so it should be allowed.

Likewise, suppose a character is being threatened by the advancing wall of a cloudkill spell, and they attempt to use gust to push it back. As stated before, the gas from cloudkill is a magic effect (not a creature or an object), so we have no explicit statement of how gust will affect it. But we do have a general principle - it will produce a harmless, sensory effect. "Sensory" sets our lower limit - whatever gust does, it won't be nothing - it will at least be noticeable. "Harmless" sets our upper limit - it can't divert the cloud onto a nearby creature, nor can it blast air in the face of the cloudkill's caster and force a Concentration save on their spell. Another upper limit is set by the text of the cloudkill spell itself - gust is not a strong wind and can't disperse the cloud. So we have a range of possibility - the effect of gust must be at least noticeable but not so great that it harms a creature or ends the spell. Within that range, the DM will need to make a ruling on exactly what effect the gust has, in a way that makes sense for their world - that is, Rule 3 - the DM describes the results of the characters' actions.

This effect might be as little as cosmetically pushing back the tendrils of deadly gas before it inevitably envelopes a creature anyway, or as strong as delaying the advance of the cloud for a round in a single 5' square. It might be as little as making a single square in the cloud lightly (rather than heavily) obscured, to as much as giving a single creature advantage on its save or even obviating the save for one round. The DM will need to decide, making a ruling for the effect of gust that is somewhere between nothing and ending the spell.

1 For the duration of the spell (instantaneous), it is able to move an object ten feet. Unfortunately, we don't know how long it takes to do that - the entire six second round or only a portion? That ten feet would have to be covered in a third of a second for it to approach 20mph.


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