So you can see out of the fog without issue..... interesting

Quote from PoorWanderingOne >>

So you can see out of the fog without issue..... interesting

 

It very much does not say that, and you cannot see through the fog unless you have some other feature that allows that.

I don't suppose Elementalism could counter this.

Quote from hermick >>

I don't suppose Elementalism could counter this.

I would say no. This spell says it can be disrupted by "a strong wind", but the description of Elementalism says it can produce "a breeze strong enough to ripple cloth, stir dust, rustle leaves, and close open doors and shutters". That does not sound like a strong wind to me.

Plus, this spell offers an example of an effect that can disrupt it: the spell Gust of Wind. This is a 2nd level spell, so it seems unlikely that the intent is that a cantrip could also disrupt it.

Also, Elementalism only affects a 5-foot cube anyway, while this spell has a much larger area of effect. As a DM I might allow a character to clear a 5-foot cube of this spell's effect out temporarily if they wanted to.

I understand that this spell creates a Heavily Obscured volume, and I understand what the Blinded condition does. I'm confused on the definition of Heavily Obscured: "You have the Blinded condition while trying to see something in a Heavily Obscured space." Interpreting this definition in a vacuum, does this mean 1) "...something while you are in a Heavily Obscured space," 2) "...something that is in a Heavily Obscured space," or 3) both?

As per the "Exploration" section of Chapter 1, a volume of nighttime darkness is just as Heavily Obscured as the same volume being in daylight and subject to this spell. You can definitely see the light of a city from a lake at night (implying case 2), so you should be able to see out of the fog just as well...? I agree that this doesn't make sense - being able to see what's on the other side of fog whose contents is obscured to you - but that seems to be the case RAW. Please correct me if I'm mistaken!

Quote from PurplBanana >>

I understand that this spell creates a Heavily Obscured volume, and I understand what the Blinded condition does. I'm confused on the definition of Heavily Obscured: "You have the Blinded condition while trying to see something in a Heavily Obscured space." Interpreting this definition in a vacuum, does this mean 1) "...something while you are in a Heavily Obscured space," 2) "...something that is in a Heavily Obscured space," or 3) both?

As per the "Exploration" section of Chapter 1, a volume of nighttime darkness is just as Heavily Obscured as the same volume being in daylight and subject to this spell. You can definitely see the light of a city from a lake at night (implying case 2), so you should be able to see out of the fog just as well...? I agree that this doesn't make sense - being able to see what's on the other side of fog whose contents is obscured to you - but that seems to be the case RAW. Please correct me if I'm mistaken!

The way I interpret this spell is #3) Both.  If you are outside the fog, you can't see anything inside the fog (and it blocks your view of anything on the other side as well).  If you are also inside the fog, you can't see anything - a fog so think you almost literally can't see your hand in front of your face.  You know...like a thick fog.  

As per the Exploration section of Chapter 1:  "A Heavily Obscured area—such as an area with Darkness, heavy fog, or dense foliage—is opaque. You have the Blinded condition (see the rules glossary) when trying to see something there."  I don't see anything in RAW or the spell description that implies that you can see out of the fog if you are inside it. 

Spells that exempt the caster usually state as much - along the lines of "everyone other than you has the blinded condition".  Take for example,  entangle: "Each creature (other than you) in the area when you cast the spell must succeed on a Strength saving throw or have the Restrained condition until the spell ends." - but this spell doesn't say that.  If you could see out it would effectively render you invisible

Nighttime Darkness creates a Heavily Obscured area, RAW. This spell creates a Heavily Obscured area with no additional effects. How is it, then, that a character can see the moon at night, but a character can't see out of a Fog Cloud? Indeed - RAW - either you cannot see the moon at night if nighttime Darkness is as opaque as a Fog Cloud, or you can see outside a Fog Cloud just as well as you can see the moon at night.

Like I said, I agree this doesn't make sense. The issue is with the definition of all Heavily Obscured areas being opaque. Even in 2014, those areas "block vision entirely," so it was and is fundamentally flawed.

Of course, any reasonable DM would say that this Heavily Obscured area is opaque, while nighttime Darkness is not.

You can see the moon at night because it is luminous itself. Light emitted from it goes directly to your eyes allowing you to perceive it. Heavily Obscured like at night means no light is present to reflect off of non-luminous things so that NO reflected light from the object goes to your eyes therefore its presence is not perceivable. Within the Fog Cloud no light can pass through the Fog meaning no light can reflect off of anything within (nothing inside is perceivable by vision) nor can light enter if you're in there from without therefore making anything outside also imperceptible to those within.

How can moonlight pass through the nighttime air if light cannot pass through the fog? They're both Heavily Obscured, so they should both be opaque; that is, unless you mean to say that, if one can see the moon, no point in space between the viewer or the moon is actually Heavily Obscured to begin with (though, again, the rules say most moonlit nights create Darkness, which is Heavily Obscured).

If that's the case, say you're standing in the middle of an dark, open room. You can make the entire Heavily Obscured room not Heavily Obscured by lighting a candle? Someone across the room could see the candle since its luminous, so that must mean no space between the viewer and the candle is opaque, so none of it is actually Heavily Obscured... right?

Truthfully, I was just pointing out that the Heavily Obscured rules don't support some reasonable things we assume to occur. Which doesn't really matter, since we're both reasonable enough to assume how these situations are intended to work.

First of all, realistically speaking, light passes through air and fog differently because fog is made up of water vapor, so the entire premise of this question is shaky, but I will weigh in anyway. 

TLDR: At the end of the day, the Heavily Obscured condition is meant to represent spaces in which vision is, well, obscured. If you are standing in an area of heavy obscuration, those attempting to perceive you cannot see you because the obscuration blocks their eyes' ability to perceive you. If, in contrast, there are spaces of heavy obscurement between you and a target you are attempting to visualize (as with fog), then they become Heavily Obscured to your eyes, because you cannot see them. 

To get more specific:

You are assuming that every space in the world where it is night is Heavily Obscured. Night is dark because there is an absence of a powerful enough light source to illuminate the darkness (as a general principle, because the sun is not visible or providing light), thus making areas where light does not reach Heavily Obscured. This does not mean that every square inch of the universe is Heavily Obscured just because it is night.

Yes, you can see the moon at night if there is no cloud cover (clouds are also made of water vapor, just like fog, and thus block the light). You can see the moon (a light source) in the distance because the moon gives off dim light, thus illuminating the spaces between you and the moon and thus removing the Heavily Obscured condition from those "spaces," if you will. The world itself is not necessarily dimly lit everywhere, obviously, even by RAW. There is, however, light being emitted from the moon, and it is making it to your optic nerve, thus allowing you to perceive it, because those spaces between you and the moon are not obscured by darkness; they are pierced by the light of the moon. Even if you look to your left, that space is obscured by darkness; the spaces above that are lit by the moon are not dark and are thus not obscured. If a cloud passes between you and the moon, it will obscure your vision of the moon, as well as cast shadows over the land, potentially creating some new areas of Heavy Obscurement. Likewise, if you were to go into a forest on a moonlit night, you would be in an area that is truly dark and thus Heavily Obscured. If you find a break in the trees where light from the moon shines through, illuminating that small section, then that area is not Heavily Obscured anymore, and if you look up and see the moon through the break in the trees, that is because your vision is not obscured. Of course, if you have Darkvision, this is a moot point, because night is not darkness to your eyes, although magical darkness still is. 

To the question about the candle: Yes, if you are in a dark room and light a candle, you absolutely would remove the Heavily Obscured condition if it is created by nonmagical darkness, because the area within the radius of the light is now Bright Light and then Dim Light. If there are corners of the room that are still shadowed because the room is large enough that the light does not reach those corners, then those individual spaces that remain dark are thus Heavily Obscured. In this particular case, the spaces in between are not Heavily Obscured and thus do not block your vision even if you are in one of those spaces that are Heavily Obscured, because you are looking through spaces that are not Heavily Obscured to see a target. Magical Darkness is a different beast, because it is heavily obscured in the entire area, and specifies that it cannot be illuminated by nonmagical light and that Darkvision cannot see through it, thus clearly differentiating it from standard nonmagical darkness. 

Regardless, fog and darkness are different in general. Yes, both create the same condition, but light does not remove the Heavily Obscured condition that is caused by fog, just like wind cannot remove the Heavily Obscured condition if it is created by darkness. That simply isn't a thing. If you are in an area of dense fog, you often cannot see the headlights of a car 20 feet in front of you, and you certainly can't see anything farther, nor can someone outside of the fog look in and see you, even if you have your headlights on. This is because all of the space around you is opaque, thus blocking your vision and the vision of anyone who might look your way. 

As I said before, it is all about perception. Heavily Obscured occurs when something like Fog or Darkness blocks perception of a creature, object, or otherwise by creating conditions that you cannot see through, thus making you "blind" when you attempt to perceive something in or through an area that is Heavily Obscured, and making the one you attempt to visualize effectively Invisible to your eyes. 

Hope that helps. :) 

As a clarification: As Jefwfunk mentioned, it does have to do with light being able to reach your eyes and thus allow you to see (in the most basic terms), and light does, in fact, pass through fog and clouds differently than air. This is why you can see something that is lit in the distance if all that stands between you is darkness, but you cannot see that same object through fog (or cannot see the moon, or even the sun through clouds). Fog has physical substance; it blocks light and vision. Darkness (excluding magical darkness) does not. Just because you may "face darkness" at night, does not mean everything everywhere is dark, only that darkness exists at night (which it does). I will grant you that if you feel the need to be "technically correct" about the opacity nonsense, then sure, the wording is iffy there, because while the areas are opaque, they have different physical properties, so the opacity does not realistically function the same. I would argue that lighting rules would be more specific than the obscuration for darkness, and thus would need to be considered in making determinations where rules for Darkness might differ from rules for other areas that are Heavily Obscured (such as dense foliage and fog, both of which have a physical presence and block light in a way that nonmagical darkness cannot and does not). But if we ignore lighting rules, then sure, it is not technically incorrect to claim inconsistency.