D&D 5E Line or Cone, why aren't there any breath weapons with a Burst Area of Effect?

[pemerton]

In Moldvay Basic (B/X) a Green Dragon's and one of the Gold Dragon's breath weapons was gas in a cloud shape, but it had to be directly in front of the dragon, not a ranged burst.

<snip>

In AD&D clouds are similar, green dragons and metallic dragons have cloud breath weapons with rectangular dimensions.

1e MM page 33:
A green dragon can attack by a claw/claw/bite routine or by breathing a cloud of poisonous chlorine gas. The gas cloud is 5” long, 4” wide, and 3” high.

Right. These are pretty close to being bursts (I mean, AD&D cones could have varying ratios of width to length, compared to the uniformity of 5e).

The classic D&D cloud is reasonably close to a 20' R burst at a range of 25' from the dragon.

 

[Stormonu]

Currently in 5e D&D (and as far as I know), breath weapons produce two Areas of Effect-either a line breath weapon or a cone breath weapon. I haven't seen any breath weapons with a burst area of effect. Why is that? curious

Feed it a diet of cabbage and you can fix that real quick.

 

[Vaalingrade]

Dragons either cannot or have not mastered 'turning your head while exhaling' technology.

 

[cbwjm]

I think the 3e draconomicon had breath weapon feats that allowed them to adapt their breath weapon, turning it into a ranged fireball like effect. I think adjusting breath weapons like this is a cool little twist, might be a bit of a surprise for the players. I think there was a spell that also altered a breath weapon to a new damage type, imagine going up against a red dragon with fire protection, only to be hit with a cold breath weapon.

 

[Stormonu]

I think the 3e draconomicon had breath weapon feats that allowed them to adapt their breath weapon, turning it into a ranged fireball like effect. I think adjusting breath weapons like this is a cool little twist, might be a bit of a surprise for the players. I think there was a spell that also altered a breath weapon to a new damage type, imagine going up against a red dragon with fire protection, only to be hit with a cold breath weapon.

Most of the older dragons have Legendary Actions, and it would be easy to add a mini-blast as one their actions, costing 2 actions and doing a bite's worth of damage in a small area (15 ft.) or short line (20 ft.).

 

[Charlaquin]

Currently in 5e D&D (and as far as I know), breath weapons produce two Areas of Effect-either a line breath weapon or a cone breath weapon. I haven't seen any breath weapons with a burst area of effect. Why is that? curious

Well for one thing, burst isn’t one of the shapes an AoE can take in 5e. 5e has cones, lines, spheres, cylinders, cubes, squares, and circles. Of those, only cones and lines project directionally from their point of origin. The other shapes radiate equidistantly, which would be a bit of an odd thing for a breath weapon to do.

 

[doctorbadwolf]

One of these days, I’m gonna go ahead and build dragons as the idealized version of how I’ve always used them and wished they were in the books.

Spitting a napalm bomb that does a ball of acid and fire damage? Hell yeah!

 

[CleverNickName]

When I imagine a breath weapon with a burst effect, my mind goes here:

 

[Staffan]

3e took away the the cloud and turned the green's chlorine gas into acid.

Page 75 of the 3.5 MM:

"Breath Weapon (Su): A green dragon has one type of breath weapon, a cone of corrosive (acid) gas."

It should be noted that at least in 3e, "acid" really meant any type of chemical damage. Also, the main way chlorine gas works as a weapon is reacting with moisture in your throat and lungs to form hydrochloric acid (which is why you get pretty good protection with "just" a gas mask, unlike many other poison gases which can be absorbed through the skin).

In 5e, I can't find anything about their breath being specifically chlorine, but instead just generic "poison" as part of a general theme of corruption.

 

[RoughCoronet0]

Ranged aoe and “centered on the dragon” elemental attacks are one of the things I’m working on as variant features for dragons in my setting, among other features. I want to give my dragons a wide variety of abilities that can make each one unique.