Does an "acid" Burning Hands still set things on fire?

Question

The spell burning hands can set targets on fire, if they can burn. Now I am wondering what will happen if a sorcerer with the elemental bloodline chooses to change the damage type of the spell to, say, acid. Does the spell still set targets on fire? That seems nonsensical, but I can't find anything on different effects of different energy types (at least not in the german prd: prd.5footstep.de)

note: coming from e.g. The Dark Eye, where spells like an elemental ray have different effects depending on the elemental type you choose, it would make sense that the spell has different effects. That's why I'm asking, even though the RAW answer would probably be "It says nowhere that it does no longer burn enemies or that the burning is in any way dependant on it beeing fire damage, so it will still burn enemies"

Answer 1

The rules would have it do so, yes

The sorcerer’s elemental bloodline literally does nothing but swap the damage type of the spell; all other effects remain the same. In effect, an acid burning hands still launches a jet of flame and still sets things on fire – it’s just that the fire and flame now deal acid damage instead of fire damage. This can, of course, be easily justified as, “hey, it’s magic.”

Of course, seeing as acid’s effect is frequently described as a burning sort of feeling, this isn’t much of a stretch – the action to “put out the fire” could be “wiping the acid off” and “dousing” it could be “diluting” it. In most cases, “being on fire” is entirely equivalent to just “taking damage-over-time that you can use an action to end.” But then if you consider a spell that magically puts out fires – which would work – it gets a little tougher to explain.

It doesn’t have to be this way, of course. The DM certainly has purview to change something like this, and there is certainly room for adding variety this way. The problem is that the game does not define obvious substitutions to use; fire damage sets things on fire, but it’s less clear what the rest should do if you want them to all be distinct. Even setting up distinct damage-over-time effects is awkward – some spells douse fires, but there won’t be any spells that end these new damage-over-time effects that you make up.

Which is, of course, why the rules don’t do this: having a unique status effect tied to each energy damage type requires having the rest of the game react to that fact. Pathfinder doesn’t, and adding it now would be very difficult.¹ It’s much easier to say “it’s acid-damage-dealing fire, deal with it; magic, yo,” than to write out specific versions for each element, and then make sure they’re all reasonably competitive with one another, and that the rest of the product line takes into account, and so on.

1. ^{Remember, even when the elemental bloodline was written, much of “Pathfinder” was already “written” – the core rules did not change that much from 3.5, and most of 3.5 was just used as-is. A change like this would have required rewriting substantial portions of 3.5 that they chose to leave alone, and thus even at the “beginning” would have been very difficult.}

Answer 2

short answer: no, it does corrosive damage instead.

longer answer: magic can be nonsensical or it can be scientific. How do you as a DM define Burning Hands, does actual physical fire come from the hands, or colored light that looks like fire? Id the 'fire damage' actual fire or 'magical damage that is attuned with the mystical frequency of the elemental plane of fire'?

So, you have two options here (more really, but let's start small), one BH makes FIRE and when you change it, you no longer make FIRE you make actual real live acid. This splashes, gets on things and causes caustic dissolving corrosive damage.

If however, BH causes magic light and fire attuned mystical energy damage, then you deal earth damage and your lasting damage effect is acid, but does continual earthdamage each round...

Personally, I prefer scientific based systems, but also see a lot of fun with magic energy systems too. Once you or your DM answer the question of magic in their game world being, a special way of causing real, scientific effects, or in being 'magical energy attuned to certain 'types', the answer is much more clear. I tend to find this as being up to the DM in terms of their game world or the literature of the world you are using.

Answer 3

PRD clearly states Sorcerer :

Whenever you cast a spell that deals energy damage, you can change the type of damage to match the type of your bloodline. This also changes the spell's type to match the type of your bloodline.

Burning Hands is no longer going to set something on fire as it's spraying acid- there is no longer any element of fire involved- it's been changed to Acid Spray.

Even if PRD didn't come spell it out - it also wouldn't be in the spirit of the game to have burning hands spray flaming acid- and NOT do fire damage- even if it was somehow reduced to a secondary effect. The statement "The sorcerer’s elemental bloodline literally does nothing but swap the damage type of the spell; all other effects remain the same." is both literally and figuratively contradicted by RAW:

The power of the elements resides in you, and at times you can hardly control its fury. This influence comes from an elemental outsider in your family history or a time when you or your relatives were exposed to a powerful elemental force.

The point of the Elemental sorcerer is that the elementals are a part of your very being so the idea of an earth elemental (energy type acid) that also shoots fire (a different element type) doesn't make sense. Its also clear that there is confusion about what a Descriptor entry is: Here is the definition from the PRD:

[Descriptor]

Appearing on the same line as the school and subschool, when applicable, is a descriptor that further categorizes the spell in some way. Some spells have more than one descriptor.

The descriptors are acid, air, chaotic, cold, darkness, death, earth, electricity, evil, fear, fire, force, good, language-dependent, lawful, light, mind-affecting, sonic, and water.

Most of these descriptors have no game effect by themselves, but they govern how the spell interacts with other spells, with special abilities, with unusual creatures, with alignment, and so on.

A language-dependent spell uses intelligible language as a medium for communication. If the target cannot understand or cannot hear what the caster of a language-dependent spell says, the spell fails.

A mind-affecting spell works only against creatures with an Intelligence score of 1 or higher.

Emphasis mine-

Lets look at the other important detail - Description:

Description

The description is the meat of the spell, and what you put here is the most important information of all....People who read your spell description may not know your intent, and using flavorful language can trick readers into thinking a spell > should have additional effects not explicitly spelled out in the description.

Both from Designing Spells. The point of the descriptor is not some meaningless check vs damage type resistance entry, but actually how the spell interacts with both other spells and the environment. It "describes" the type of force/energy type used.

Lets look at the description of the Elemental bloodline where Burning Hands is SPECIFICALLY called out

These spells always deal a type of damage determined by your element. In addition, the subtype of these spells changes to match the energy type of your element

But uh-oh even though Burning Hands is in the list of specifically changed spells it uses the word subtype instead of descriptor - and since spells have no such thing as a subtype it's clearly not really meant to apply....

OR

the subtype is meant to infer the meaning that both the descriptor and possibly description are supposed to change- when the caster chooses the secondary energy type. Note that with burning hands specifically - you don't get a choice, unless you are a fire element you do not get fire as the energy type. There is something else missing here. It doesn't say "descriptor" it says "energy type" - something else a spell doesn't have. So again either you decide that the core rulebook is just plain wrong, or you decide that they probably meant something broader than just descriptor since that fits in with what the character is supposed to be (elemental in nature).

Lets look at the description of Burning hands:

A cone of searing flame shoots from your fingertips. Any creature in the area of the flames takes 1d4 points of fire damage per caster level (maximum 5d4). Flammable materials burn if the flames touch them. A character can extinguish burning items as a full-round action.

So if we don't change the description (which would then have to override the class description) yup you get to spray fire that happens to deliver acid damage (even though the class specifically calls that out- you have to ignore that) and it also means that though you have acid damage you get NO acid effect from spraying the acid "fire". that's neither the intent or any sort of reasonable interpretation of the rules IMHO. Additionally the description presumes that FIRE is going to be created. Being 20 some odd years old, this isn't an unreasonable assumption but the PRD addressed this in the description of sorcerer.

As an aside there no requirement in the rules to turn off your brain. Pathfinder and DnD in general isn't meant to be advanced squad leader, so sometimes you are going to have to make allowances for older rules to combine with newer ones. In general these can be resolved using common sense and specified intent in the guides (which is usually very explicit)