That's not how the dispelling would work. Darkness can dispel weaker light sources, but it isn't inherently vulnerable to stronger light sources. Whether something dispels something else is specified in the stronger spell. Eg: Daylight specifies that it can dispel weaker darkness spells, but Wall of Light and Dawn don't do that.

I would take this spell purely for RP and flavor purposes. An idea in particular is a sorcerer trying to intimidate someone and glancing over to his guard/buddy and using subtle spell to cast this and be like "Your friend was set ablaze by the power of my mind merely out of annoyance, what do you think I'll do to YOU if you continue along this path?"

Quote from KaptainKittens >>

I don't understand why this spell can't be extinguished by nonmagical means, but can end because the target succeeds on a Dexterity save. What are they doing as part of their save to extinguish the flames that no other nonmagical means can achieve?

 

 

Beyond 20

 

 

 

 

 

Agreed. I think CON would be better for the subsequent saving throws. Stop, drop and roll which would be my DEX save of choice if ever I were on fire just wouldn't work here.

Quote from Calex0 >>

It's a weak spell, though I can think of a couple of niche uses:

1. If it can't be extinguished by nonmagical means, that suggests it could be cast on a submerged target without the usual fire resistance. 

 No, it's just not ended by water. It still only deals half damage underwater.

Might be better if it takes 3 saves to end the spell. It is concentration and not particularly better than flaming sphere, at least that doesnt end on a failed save, always does at least half damage, can switch targets, and has 1d6 more damage per turn at this level. This spell by comparison is a mediocre immediate damage spell with damage over time potential if you are lucky, and doesnt get an upcast bonus.

Quote from ErisTheErotic >>

I would take this spell purely for RP and flavor purposes. An idea in particular is a sorcerer trying to intimidate someone and glancing over to his guard/buddy and using subtle spell to cast this and be like "Your friend was set ablaze by the power of my mind merely out of annoyance, what do you think I'll do to YOU if you continue along this path?"

 Lol,yeah!

Also, I'd like to add that, unlike spells like fireball, this can be used with warcaster to attack a fleeing enemy, and potentially burn them to ash, and unlike disintegrate, their non magical items (ie gold) will be safe for looting.

Quote from ZeggVonTheodrakugard >>

Quote from Cryptobranchus >>

I have to disagree.  It takes two rounds, your concentration, a fifth level slot, and two failed saves to deal one target 12d6 points of damage of the most resisted damage types in the game.  This is doing 42 damage over two rounds - an average of 21 points of damage per round - and that's assuming two fails (other resources of players used to stun, etc.)  Sure, the second 4d6 doesn't take your action or a spell slot, but we're talking 1st or 2nd level spell damage there.  This is the absolute best case scenario - two failed Dex saves - and you're still only dealing 42 damage over two rounds.  Fireball, a level 3 spell, does an average of 28 over a 20 foot radius; upcast to 5th level, it does 35 damage as an area of effect - almost as much this spell does in two rounds while using your concentration.

By comparison, Animate Objects is a 5th level spell that takes your concentration, but you can use it to make 10 objects that have +8 to hit and deal an average of 6.5 points of damage each.  If only half of them hit, and with +8, this shouldn't be a huge issue, you'll do 32.5 points of damage in the first round.  You also have a 40% chance of a critical hit with ten attack rolls.  If you can somehow paralyze, stun, or otherwise impede a creature like suggested in the previous comments, your damage goes WAY up, with more hits and more crits.  While they can and will be destroyed (which may take away enemy actions), they can continue attacking using your bonus action - if they aren't attacked, they can do just as much damage on turn two as they did the first turn.  On top of all that, they can offer flanking if you use those rules, can make opportunity attacks, and have some utility outside of combat (ordering a door to stay shut, or serving as a flying platform for a bit, etc.)  Their big weakness is that they do non-magical damage, which is frequently resisted at higher tiers of play.  

Alternately, Synaptic Static does 8d6 damage at 5th level, the same as the first round of Immolation, and it targets a much better saving throw.  It's also area of effect, AND it offers a really great secondary benefit that persists, without requiring concentration.

This spell really needs to be improved to make it useful.  Remove the concentration requirement and up the damage and maybe you've got a good spell for times when you want to deal damage to a single target.  As it is, there's really no reason to ever prepare this, even if you get the spell for free.

 

 I have to disagree with you. This spell may be a bit weaker than other spells of its level, but with good teamwork and a simple Elemental Adept, you can deal ridiculous damage with this spell. Keep in mind that the 4d6 damage from this spell happens EVERY TIME they fail the DEX save after the initial hit. So it's 8d6, plus 4d6x10, which is a total of 48d6 damage, or on average with Elemental Adept, 192 damage over the course of 1 minute, at which point most combat encounters usually end. That is just too good to pass up, especially if you have a monk that can keep stunning the opponent, or something that can keep them restrained. 

You're assuming enemies will fail all the DEX saves... Plus if they pass a single one, that's it. This Spell is really, really, really weak. It's only strong if you can keep the effect going for multiple rounds but combat generally ends in 3~4 rounds. So at max you're looking at 8d6+4d6(1st round)+4d6(2nd round)+4d6(3rd round)+4d6(4th round) so 24d6 MAX, of the most resisted damage type in the game, over 4 rounds (average of 132 damage total, 33 damage per round) and takes Concentration. You never get combats that last half a minute much less a whole one, so it's pretty disingenuous of you to calculate the total damage of the Spell assuming it does damage over 10 rounds. Not to mention the target has to fail every single one of the DEX Saves, that won't happen. You also have to keep up your Concentration. Which again, probably won't happen.

This is not a good spell, at all.

Simple balance to this spell would be to have no saves for the ongoing effect. First save fails then they're immolated. An unstoppable, unquenchable fire charring them to ash as long as your concentration holds; exactly the spells intended flavor. If this adjustment is too strong, bump it up to 6th level. Or keep the save, but for half damage, not for ending the effect.

I disagree with comments asking to switch to Constitution, as most times you want to use a single target spell is against high Con bosses, which often have low Dex. I just think that Immolation should feel like a save or suck spell. "I am engulfed in magical fire", that should be a threatening state not something I shirk off passively at the end of my next turn.

See I would have gone with “The Intrepid”, aka “Roy Mustang casts Immolate at will on Envy.” 

The average initial damage of immolation is slightly more than a 3rd level spell based on DMG 'creating a spell'  damage recommendations.  If you include both the initial and end of turn damage then it reaches the recommended amount of damage for a single target 5th level spell but has others have mentioned this requires two failed saves.

If you bumped immolation down to 4th level then taking into account the probability of hitting both saves the damage would be appropriate.  Similarly moving the end of turn saves to after the damage would be enough to make this spell do a 5th level spells worth of damage. 

At 4th level it would be competing with phantasmal killer which does more damage per round and gives the frightened condition at the cost of not getting the initial damage of immolation which I think makes the two spells similar power. 

So... you snap your fingers and someone instantly lights on fire and horribly burns to death.

There HAS to be a reference to make somewhere...

Quote from HealingFighter >>

Would this work on a dead body in DnD?

I'd say yes. Unless it specifically influences minds, would say most spells that specifically say "creatures" would reasonably work on objects too, including corpses.

Quote from ErisTheErotic >>

I would take this spell purely for RP and flavor purposes. An idea in particular is a sorcerer trying to intimidate someone and glancing over to his guard/buddy and using subtle spell to cast this and be like "Your friend was set ablaze by the power of my mind merely out of annoyance, what do you think I'll do to YOU if you continue along this path?"

That'd be enough to get you rolling initiative right there. Maybe if you wanted to just intimidate you could burn down a tree or something instead.

I would point out that this is one of the few spells within only a verbal component. That means you can do it while tied up as long as you're gagged.

If your character is REALLY hard core, (or maybe fire resistant), then you could set yourself ablaze to burn the ropes to free yourself. Then stop concentrating on the spell to end it. Last resort kind of thing, but a fun idea.

Would be better as a 3rd level spell.

All people arguing how this spell is weak even don't take a look or don't care about components.
Yeah, upcast Fireball is better damage wise, but's VSM - so wizard without focus or components can do nothing.
Immolation only requires V.
Manipulating weave with no component costs is much harder spell, therefore 5th level. 

Honestly, i dont know why any other firespells exist with how broken Fireball is. 

Cool, this one does 8d6 single target damage and can potentially do an extra 36d6 if the target fails every save and you dont loose concentration. 

A Level 5 Fireball does that much damage total if you have just 4 targets in the area and all failed the save... 

Take only to weaken your teams spell pool. (Rare cases it will be useful)

Pretty useful against things that are vulnerable to fire (plant monsters, blights, cold based creatures, etc), especially if you have silvery barbs prepared to spoil its saves. 

Throw psychic lance at it on your following turns and it can't take actions, reactions or bonus actions. Since the flames can't be extinguished by nonmagical means, its movement wont give it a way out (diving into ponds wont yield any relief). I love the spell but I wish you could transfer it to another target as a bonus action on your turn. Gives the caster a chance to squeeze out all of the potential damage from the spell. Just my take. 

Also combine this with an iron golem, where the target is the golem, and suddenly you have a massive ally regenerating 14 HP per round while you get to attack with other spells. 

This spell could be useful when combined with the Transmuted Spell metamagic to deal a more exotic type of damage. It is, however, underwhelming for a 5th-level spell. A potential improvement could be making the secondary damage decrease by 1d6 with each successful save, instead of ending the spell outright.