AoE reaching around corners

[Bellberith]

alright so in a conversation with my DM he is saying that if you have something like darkness on and you open the door, the total radius of the spell goes through the walls and covers the other room like normal.

I thought that the parts that would be blocked are still blocked and the darkness would have to wrap around the walls so the total area is reduced.

Which way is it? I am not certain and it doesn't seem to cover in the books.

same with fireball's explosion reaching around corners with enough radius.

[Basch]

It wraps around corners unless the source is completely covered with an opaque object like a bowl. It's in the spell description, page 230. :smallsmile:

[Bellberith]

It wraps around corners unless the source is completely covered with an opaque object like a bowl. It's in the spell description, page 230. :smallsmile:

It doesnt answer the question though. say there was a hole in a 10ft bowl, would the darkness go out only 5 ft from that hole alone or 5ft around the entire bowl.

[Kryx]

I thought that the parts that would be blocked are still blocked and the darkness would have to wrap around the walls so the total area is reduced.
Since the spell specifies that it wraps around corners I would draw a circle from the point of origin and use that.

If you use the grid system then stick with it. Math isn't employed for weapons on diagonals and it shouldn't be applied for spells wrapping around corners either.

[Basch]

Assuming there was a hole, it would go around the entire bowl, wrapping around any corners and making a sphere of darkness out to 15 feet.

[JAL_1138]

Back in Ye Olde Days, fireball filled a volume rather than an area, and could easily kill the caster in a narrow hallway. On the other hand, darkness doesn't go fwoom like a fireball.

If you cast fireball in the bowl-with-a-hole, I'd have it emerge from the hole in a cone. Darkness, though, I'd just go with radius-around-origin-point.

[Wartex1]

It should depend on how the spell works.

If it's a burst or a flash, like Fireball, then it doesn't wrap around corners.

If it's an aura or a cloud like Darkness, then it does wrap around.

[Kryx]

It should depend on how the spell works.

If it's a burst or a flash, like Fireball, then it doesn't wrap around corners.
This is incorrect. Fireball specifically says it wraps around corners.

[Wartex1]

Oh, okay.

That's how I rule spells if they don't specify.

[jkat718]

This is incorrect. Fireball specifically says it wraps around corners.

I picture Fireball as more of a constant gout of flame, rather than a fiery explosion, partially because of this rule. It's sending waves of flame to wash over the area, and the fire acts more like a gas than a liquid in this case, curling around corners and the like.


Back in Ye Olde Days, fireball filled a volume rather than an area, and could easily kill the caster in a narrow hallway. On the other hand, darkness doesn't go fwoom like a fireball.

If you cast fireball in the bowl-with-a-hole, I'd have it emerge from the hole in a cone. Darkness, though, I'd just go with radius-around-origin-point.

I like the cone-from-PoO ruling, though.

[Slipperychicken]

Fireball explicitly wraps around corners. It's written in the spell description on PHB 241-242.

[Wartex1]

Fireball explicitly wraps around corners. It's written in the spell description on PHB 241-242.

A little late to the party with that.

[Gentari]

I thought that the parts that would be blocked are still blocked and the darkness would have to wrap around the walls so the total area is reduced.


The way I interpret it is: the radius doesn't change; it's either blocked by solid objects from expanding to that pre-set radius or it's not.

So I agree with you. Mainly because it's simpler. And I like simple and fun more than tedium and math :smallcool:

[jkat718]

By the way, I found the rules text for this:


A spell’s effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn't included in the spell’s area. To block one of these imaginary lines, an obstruction must provide total cover, as explained in chapter 9.

Therefore, while spells like Darkness and Fireball (which fill their spaces) ignore this rule through Specific > General, other spells get blocked in the same manner as a light source does, or Wartex1's "burst or flash" interpretation.

[whibla]

I think a large part of the problem lies in peoples' different opinions as to exactly what, in the actual words of the spells' descriptions, "... spreads around corners" means.

Having originally come from the 44 10' cubes description of fireball I tend to see this, and similarly described spells, spreading in much the same way light diffracts through a slit.

Picture a room (built in the middle of a large open space for simplicity), 20' square, with a single door in the middle of one wall. Now imagine you cast a fireball such that it explodes dead centre of that room. Obviously the room fills with fire, but what happens outside the room?

In my version of "spreads around corners", having 'used' 10' of its 20' radius spread I simply picture a semicircle, of radius 10' (20' - 10' = 10'), centered on the doorway. Anything in this area is also affected by the fireball. Nothing beyond this area is touched.

Of course I accept that there is another way of interpreting it, namely that every point within 20' of the centre of the room, even those points outside the room, round the back, over 60' away from the centre of the explosion by any direct line that doesn't go through through a solid object, is affected by the fireball. While this doesn't make sense to me, it doesn't trouble me, as I don't use this system. :smallsmile:

In my opinion, discussions of RAW often overlook an obvious point. The rules are meant to be not only readable but pleasant to read. The choice of words used is as much down to sentence flow as it is down to formal specification. Arguing over the exact meaning of words chosen subjectively for literary appeal ... that way lies madness!

[Bellberith]

I think a large part of the problem lies in peoples' different opinions as to exactly what, in the actual words of the spells' descriptions, "... spreads around corners" means.

Having originally come from the 44 10' cubes description of fireball I tend to see this, and similarly described spells, spreading in much the same way light diffracts through a slit.

Picture a room (built in the middle of a large open space for simplicity), 20' square, with a single door in the middle of one wall. Now imagine you cast a fireball such that it explodes dead centre of that room. Obviously the room fills with fire, but what happens outside the room?

In my version of "spreads around corners", having 'used' 10' of its 20' radius spread I simply picture a semicircle, of radius 10' (20' - 10' = 10'), centered on the doorway. Anything in this area is also affected by the fireball. Nothing beyond this area is touched.

Of course I accept that there is another way of interpreting it, namely that every point within 20' of the centre of the room, even those points outside the room, round the back, over 60' away from the centre of the explosion by any direct line that doesn't go through through a solid object, is affected by the fireball. While this doesn't make sense to me, it doesn't trouble me, as I don't use this system. :smallsmile:

In my opinion, discussions of RAW often overlook an obvious point. The rules are meant to be not only readable but pleasant to read. The choice of words used is as much down to sentence flow as it is down to formal specification. Arguing over the exact meaning of words chosen subjectively for literary appeal ... that way lies madness!


This discrepancy is exactly why i made this thread.

I am one that normally goes for logic. Turn on a light IRL that is made to shed light in a 20ft radius and you wont have it shining through walls. It will go through a doorway and spread a little then stop at the end of its intended range.

To be honest i didn't think there was any other way to interpret this until i talked to someone who thought the other way. To me, that just doesnt make sense... it is as if the other way completely disregards all walls as long as there is one hole of any size in it. Basically a 5ft hole in a 20ft wall renders the entire wall useless when it comes to aoe from that perspective.