Not a good spell to learn if I'm a ranger but it is a good support spell if I'm a druid and my friend is playing ranger so I like it.

Best use of this spell is to arm minions that can shoot.  For example, wizard or spore druid animates a bunch of skeletons.  Then you have them draw arrows from the quiver (maybe leaving 1 in to keep the spell going?  Not super clear on what happens to unfired arrows if the spell ends, but I think they lose their fire damage).  

10 skeletons with fire arrows is 90 damage if they all hit, 45 if half hit.   Compared to 55/27.5 for normal skeletons.   That's a pretty sweet bump in damage for a level 3 spell, and it also allows them to bypass magical resistance.  In that case, you're taking their damage from approximately 14 to 45.  For a level 2 spell, that's pretty darn good.

You could also use the spell if you're defending a fort and you have NPC allies, although that's a pretty niche situation and you may very well have better things to contribute with your concentration.  

The only other good use of the spell IMO is for a ranger who

1. doesn't have a magic bow and needs to do magic damage to overcome resistance.  
2. is fighting something with some kind of weakness or vulnerability to fire damage (ex: Troll, Yeti, Treant)

This has got to be the lamest 3rd level spell ever. Concentration?? Lasts only an hour. And this is a 3rd level spell?? What a pile of crap. Please let me know if you have actually wasted your time with this spell.

I actually made a homebrew version of this spell to make it more useful.
https://www.dndbeyond.com/spells/782031-elemental-arrows

If you are enchanting bolts, then technically you could use this ability for single-handed crossbows in both hands.

Not a 3rd and a 1st for 2d6. This is good for 12 pieces of ammo, so that's for 12x 2d6 (though Hunter's Mark will last way longer).

So does this mean the arrow now counts for magical damage?  That is a boost when you are trying to overcome immunities to nonagical damage. 

This isn't as bad as it seems, RAW the spell ends once you draw twelve pieces of ammo but the magic on the ammo doesn't. If you have a spare 3rd level spell slot just cast this, draw the ammo and return it and you can create 12 flame arrows.

Quote from SupremeGrandMasterGabe >>

This isn't as bad as it seems, RAW the spell ends once you draw twelve pieces of ammo but the magic on the ammo doesn't. If you have a spare 3rd level spell slot just cast this, draw the ammo and return it and you can create 12 flame arrows.

 I’m not so sure.  Otherwise, why would there be concentration and a one hour duration?  How do others read this?

Quote from tinyfellow >>

but i believe that the piercing damage from hunters mark counts as magical, and i don't think any creatures have resistance to magical piercing damage. 

 Treants and Awakened Plants are resistant to bludgeoning and piercing (though not slashing), regardless of whether the attack is magical. All of those things happen to be vulnerable to fire as well, so they're the only things you'll ever use this spell on, realistically.

Ok damn, do you all really only pick spells for max usefulness? this is a role-playing game remember... my ranger took Flame Arrows because the Fury sent her to the rescue of one of her clerics and gave her fire arrows to do it with. And I'm totally cool with that. Hunters Mark is great but I use that all the time. Plus, I mean.. fire arrows! It looks cool at the very least and will give our bard a new stanza to add to the saga of our adventures, what more do you need from a D&D spell?

Ack! Why do 9/10 druid spells have to require concentration?! A fireball does 8d6 to an AREA in a single turn. Even if it only hits two people and one of them saves, that 12d6 fire damage and it didn't take 12 attacks to dispense! Concentration makes this basically useless.

Next thing you know, they're going to make goodberry a concentration spell...

This is awesome, I'm going to take this on my Hunter Ranger along with Metamagic Adept for transmute. Suddenly I can change flame arrows into acid/cold/lightning/poison/thunder arrows too!

Planning to do the same with L3 Lightning Arrow aswell ^_^

Also it's 'extra damage' so that 1d6 must be in addition to the base arrow attack (1d6+Dex shortbow for me) so it's 2d6+DEX with this spell for each of the 12 arrows, or when transmuted into a damage type a mob is vulnerable to it will be 3d6+DEX total. That's per arrow. It's awesome.

contender for worst third level spell?

Quote from OohlakahnShortcloak >>

This is awesome, I'm going to take this on my Hunter Ranger along with Metamagic Adept for transmute. Suddenly I can change flame arrows into acid/cold/lightning/poison/thunder arrows too!

Also it's 'extra damage' so that 1d6 must be in addition to the base arrow attack (1d6+Dex shortbow for me) so it's 2d6+DEX with this spell for each of the 12 arrows, or when transmuted into a damage type a mob is vulnerable to it will be 3d6+DEX total. That's per arrow. It's awesome.

Quote from starrybard >>

Not a good spell to learn if I'm a ranger but it is a good support spell if I'm a druid and my friend is playing ranger so I like it.

  I'm glad you like it, and I feel like a jerk for saying this, but that's really not good at all.  Both Rangers and Druids have access to much better spells than this like conjure animals, entangle and faerie fire are both better support. This spell is painfully weak, and using up a druid's or ranger's concentration and action on it is so weak thats it's fair to say you're essentially holding back just by taking or using this, especially if you're the ranger because there's a lot of abilities you need your concentration to use and you've wasted a learned spell. Unlike rogues, rangers can use longbows, using a shortbow is already voluntarily making yourself weaker. (unless it's magic and you couldn't get a longbow version) using a shortbow AND this spell is fighting like someone half your level.
There's exactly one situation where this spell is at least okay, and that's when multiple people can draw arrows from the quiver, bonus if any of them are hasted or have action surge. I think that's the reason it's so weak in literally any other situation. 
I'm not telling you this just to say you shouldn't use this, but I am saying it's a spell that's mathematically very bad most of the time, and you should either talk to your DM about buffing it, or at least know that you're holding your character back for the sake of coolness (which is fine)

Quote from ShaydyCharacter

  I'm glad you like it, and I feel like a jerk for saying this, but that's really not good at all.  Both Rangers and Druids have access to much better spells than this like conjure animals, entangle and faerie fire are both better support. This spell is painfully weak, and using up a druid's or ranger's concentration and action on it is so weak thats it's fair to say you're essentially holding back just by taking or using this, especially if you're the ranger because there's a lot of abilities you need your concentration to use and you've wasted a learned spell. Unlike rogues, rangers can use longbows, using a shortbow is already voluntarily making yourself weaker. (unless it's magic and you couldn't get a longbow version) using a shortbow AND this spell is fighting like someone half your level.
There's exactly one situation where this spell is at least okay, and that's when multiple people can draw arrows from the quiver, bonus if any of them are hasted or have action surge. I think that's the reason it's so weak in literally any other situation. 
I'm not telling you this just to say you shouldn't use this, but I am saying it's a spell that's mathematically very bad most of the time, and you should either talk to your DM about buffing it, or at least know that you're holding your character back for the sake of coolness (which is fine)

 Not certain why you're talking about shortbows: there is no part of this spell that requires you use a shortbow.  You can shoot ammo from a quiver with this magic with a longbow and deal 1d8+DEX piercing and 1d6 fire damage.

That said, this spell is rather weak, but does have some use case. For the classes that can use it:

Ranger: Potentially set things on fire from far away if your DM will allow it. Loses out on attacks, duration, and damage type consistency in comparison to hunter's mark, however, you can shoot however many things you want that aren't your target with it. This means that that one ranger who can shoot multiple targets in an area can make pretty good use of the spell. If you were to kill your hunter's mark from far away while they are among a group of other foes, you would not be able to cast hunter's mark on the next target because they are not within your hunter's mark range, whereas you *would* be able to shoot them with fire arrows. However, there are better choices for a third level spell slot in most cases.

Druid, Sorcerer, Wizard, Artificer: these pretty much all have the same utility out of this: you can potentially set things on fire from far away if your DM will allow it if you have the ability to use a bow of any sort, and you can give it to a better bow user to buff their long-distance damage capability. 

Overall: it gets most of its utility when you're shooting from far away. 

Quote from Patrope >>

Arcane Archers should be able to learn this spell naturally. Of course maybe have it so that they can only use it once per long rest or something. 

 I might houserule that.  Probably at 7th, 8th, or 10th level, because 10th-level is when Eldritch Knights learn 3rd-level spells.  Then again, that's how Eldritch Knight stands out in it's own way.  Arcane Archer is designed to be a more "magical" variant of Battle Master.    

Quote from tinyfellow >>

but i believe that the piercing damage from hunters mark counts as magical, and i don't think any creatures have resistance to magical piercing damage. 

 The difference is the damage bonus from Flame Arrows can apply to any creature you shoot, while hunter's mark only takes effect on one specific target.  With hunter's mark, you are going to have to focus down one target before moving to another (when you can change the creature that is affected by the mark).  Then again, the tactic that I described above is a great one, because it reduces the amount of enemies on the battlefield.  So hunter's mark is still a better spell, and this one needs a buff.  Yikes, you can only shoot 12 pieces of ammunition before the spell ends!  C'mon!  Flame Arrows needs a big change in order to bring it on par with hunter's mark.  Well, I guess the issue with hunter's mark is it is only available to rangers, while flame arrows is available to a broad spectrum of spellcasters.  Also, flame arrows can be used on allies.  Maybe remove the concentration requirement.    

If you would have properly read what the person you're quoting posted, you would understand why they mentioned shortbows and realize that you are saying the same thing as them regarding shortbows(aka why not use a longbow when you have proficiency).

Also, about the only time I can see this spell being useful, as is, is when you have a bunch of weak things to take out that are just durable enough to survive your unbuffed attacks.  But at that point why not just use AoE.

Quote from ZestyVentricle >>

Quote from SupremeGrandMasterGabe >>

This isn't as bad as it seems, RAW the spell ends once you draw twelve pieces of ammo but the magic on the ammo doesn't. If you have a spare 3rd level spell slot just cast this, draw the ammo and return it and you can create 12 flame arrows.

 I’m not so sure.  Otherwise, why would there be concentration and a one hour duration?  How do others read this?

 You touch a quiver containing arrows or bolts. When a target is hit by a ranged weapon attack using a piece of ammunition drawn from the quiver, the target takes an extra 1d6 fire damage. [[[The spell’s magic ends on the piece of ammunition when it hits or misses]]], and the spell ends when twelve pieces of ammunition have been drawn from the quiver.

---------

Most people on this forum assume that the 12 pieces of ammunition lose their magic when the spell placed on the quiver ends. However, the wording of the spell specifically seperates the effects on the ammunition and the quiver. And states that the spells magic on the ammunition ends either on a hit or a miss. And the spell ends when 12 pieces of ammunition have been pulled from the quiver as opposed to ending after the 12th piece of ammunition has either hit or missed. 

We all agree that the spell is weak if the flame arrows lose their magic after the 12th piece of ammunition is drawn. That would mean that a player only gets to fire 11 pieces of enchanted ammunition. 

Given that this is a 3rd level spell, a spell that should compare to other spells like fireball and animate undead. And given that power scale it is unlikely that the fire magic on the ammunition goes away unless the ammunition is actually fired. Therefore the only sensible way to interpret this spell is that it creates 1 use fire ammunition that lasts until fired. 

Though it is odd that the quiver has a 1 hour duration and concentration requirement when we assume that the enchanted ammunition retains the enchantment even after the spell on the quiver ends. Enchanting the quiver with this effect seems suspiciously pointless. Because the spell could have simply been worded "you give 12 pieces of ammunition 1d6 damage on a hit and the magic ends after a hit or miss." To explain this, we must assume that once the arrows are enchanted with fire, they are essentially an ever burning flame source until the magic on them is expended. That means that they will burn normal quivers and will require special storage.