If you get Flames of Phlegethos, should you also get Fire Bolt?

[Greywander]

If a tiefling caster takes the Flames of Phlegethos feat, should they take Fire Bolt as their primary damage cantrip?

I was going to type out a bunch of boring logic and reasons, but I'll skip all that and cut straight to my conclusion: Flames of Phlegethos probably shouldn't influence which damage cantrip you choose. If you were going to take Fire Bolt anyway, great; you just made a strong cantrip stronger. If you weren't going to take Fire Bolt, Flames of Phlegethos does nothing to address the reasons for not taking it. That said, if you don't take Fire Bolt, you should reconsider if you should take Flames of Phlegethos in the first place.

Fire Bolt is a fairly popular damage cantrip; it does have higher damage than most other cantrips, after all. However, I usually skip over it in favor of something else, for two reasons: (a) there are a lot of monsters that are resistant or immune to fire, and (b) cantrip damage is pretty mediocre anyway, so I'm more interested in useful rider effects. It's also worth noting that riders still trigger even if the cantrip deals no damage; for example, Ray of Frost will still slow down enemies that are immune to cold damage. This means even when an enemy is resistant or immune, you can still contribute to the battle.

As an example, I've been looking at a winged tiefling Artillerist artificer build. The Artillerist gets lots of nice fire spells, including the almighty Fireball, so Flames of Phlegethos is pretty appealing. However, I'm leaning more toward Thorn Whip as my damage cantrip, for a few different reasons. First, thorn whip is a melee attack with a 30 foot range. This is mostly a novelty right now, but it does mean I can attack in close quarters without a penalty. Second, it deals piercing damage. Magical BPS damage is probably the most reliable damage type in the game, with almost nothing resistant to it. Third is the rider that pulls the enemy closer to you. By itself, this is a situationally useful rider; casters don't often want enemies to be closer to them. But for a flying character, the nature of this rider transforms radically. Instead of pulling enemies closer, it's more liking picking them up and dropping them (strictly speaking, they'll only take fall damage if you pull them straight up, as pulling at an angle will result in a fall of less than 10 feet). Flying also makes it easier to position yourself so you can pull an enemy where you want them.

So which is better? Flying just high enough to stay out of melee range, yoinking enemies around the battlefield, into hazards, or just straight up so they take fall damage? Or Fire Bolt? Now, if I can, I might try to also get Fire Bolt, say, from Spell Sniper, but usually I'd rather have another utility cantrip than another damage cantrip.

I should also mention that Create Bonfire doesn't work as an alternative to Fire Bolt due to the concentration requirement; most of the time you'll be concentrating on a leveled spell instead. It does make a great backup concentration spell if you run out of spell slots or don't feel like casting a leveled spell.

[LudicSavant]

If a tiefling caster takes the Flames of Phlegethos feat, should they take Fire Bolt as their primary damage cantrip?

Depends on the particulars of your build and party situation. In your example, Thorn Whip is great if you're a flyer in a party that benefits from Prone, and you should feel just fine taking that instead.

When considering possibilities for Flames of Phlegethos builds, you may find it useful to know that Flames of Phlegethos improves your average fire damage by approximately .5 damage per die. So for example a Fireball would effectively be doing 8d6+4 damage... nearly as much as an Empowered Evocation!

Also, Flames of Phlegethos retribution damage totally benefits from things like Hexblade's Curse.

Magical BPS damage is probably the most reliable damage type in the game, with almost nothing resistant to it.

Both Radiant and Force damage are better.

[Greywander]

you may find it useful to know that Flames of Phlegethos improves your average fire damage by approximately .5 damage per die. So for example a Fireball would effectively be doing 8d6+4 damage...

Huh, I knew it wasn't going to add a lot of damage, but this does help to put it into perspective a bit. It makes me reconsider if it would be better to take a different half feat, such as Fey Touched, instead. I'm also a little unclear how this interacts with the Artillerist's bonus damage from their Arcane Firearm. The way it's worded, you're not doing 1d8 extra damage, you're rolling the d8 separately from the damage and then adding the result as a flat bonus, in which case it wouldn't be affected by Flames of Phlegethos. That seems like such an awkward way of handling it, though, so I imagine most DMs would treat it as simply doing 1d8 extra damage.

Also, Flames of Phlegethos retribution damage totally benefits from things like Hexblade's Curse.

Indeed, an ideal Flames of Phlegethos build probably looks something like a Hexblade using GFB. Someone who not only consistently uses fire spells, but is also in melee and has a way to boost the retribution damage (I sometimes refer to this kind of thing as thorns damage, or a thorns effect, due to similar abilities from video games often using a thorns motif). For a ranged blaster, like an Artillerist, you're only getting half the benefit, so a different feat might be more valuable to you. That said, it doesn't hurt to give enemies a reason not to target you.

Both Radiant and Force damage are better.

You're right, that was my mistake. I do think it's probably true that the ratio of resistance/immunity to magical BPS damage will probably stay fairly consistent, whereas we're probably just one splatbook away from gaining a bunch of new enemies with radiant or force resistance. Not that such enemies would be commonplace, or even appear in a given campaign at all. In the case of artificers, they don't have any force or radiant cantrips on their list anyway, so Thorn Whip is still probably the best pick for reliable damage.

Also, that's a handy dandy chart. Is it linked in the Notable Threads thread?

[Silpharon]

I like Thorn Whip, it's also useful to help pull an enemy off a teammate to avoid an opportunity attack.

For an Artillerist with Flames of Phlegethos, I'd recommend working with your DM to get an All Purpose Tool (you can start with the +1 uncommon variety). Learn Shillelagh from APT, then use your Shillelagh'd Arcane Firearm to cast Green-Flame Blade. You'll be hitting with 1d8+int mod + 1d8 Arcane Firearm + variable fire damage. The fire damage will use your feat reroll, and you'll get the other perk to engulf yourself in flames to damage on a counter attack (which also gets the feat reroll). If you get a Striking Staff or similar you can really hit hard.

BTW, here are the die values for Flames of Phlegethos:
d6=3.9166
d8=4.9375
d10=5.95
d12=6.95833

The benefit is a little higher for larger die rolls, but the .5 approximation works well enough.

[Corran]

Thorn whip does sound like a cantrip you should be taking. All this mobility thanks to flight can really help you be at the right position for when an effective pull presents itself. I dont expect this to be a game changer, unless of course your DM is always terribly creative with the terrain, but you dont need too much to squeeze some value out of flying + thorn whip. The occasional chasm/hazzard/etc, or even just one ally who wants to hit and run, or a PAM pc, etc. In the end, even the extra damage and proning enemies could be useful (though do be mindful of initiative so that you dont sabotage your main ranged dpr if you have one; and if you do,remind them that shooting a prone target from 5' close cancels disadvantage, and with CE on, you shoot at advantage prone targets from 5' away). All in all, thorn whip has good potential, and also sounds like the kind of at-will option that makes that adds something interesting to the gameplay of this character (tempting you to think a bit harder on positioning and generally expanding your list of at-will options).

I'd also want a ranged cantrip in my selection though. And probably one with the 120' range (because although I do like ray of frost more than the likes of firebolt and chill touch, I usually find it preferable to go for the extra range). At the very least one with a 90' range, if artificers get such cantrips. Now, if you are planning only for one such, then if possible make it be one with a damage type not too commonly resisted.

Firebolt, fireball, generally fire spells or not, I am not too impressed by flames of Phlegethos on a ranged flying build. Surely there must be a better choice.

[stoutstien]

As far as the arcane firearm goes, you would be allowed to reroll that 1d8 as well when you cast a spell that does fire damage due to the wording.

[ATHATH]

snip

What I wanna know is why those two oozes are immune to slashing damage, but not piercing damage. Surely it'd make more sense for it to be the other way around?

[stoutstien]

What I wanna know is why those two oozes are immune to slashing damage, but not piercing damage. Surely it'd make more sense for it to be the other way around?

They aren't actually homogeneous blobs so the centers are more vital?

[LudicSavant]

What I wanna know is why those two oozes are immune to slashing damage, but not piercing damage. Surely it'd make more sense for it to be the other way around?

It's because slashing a Black Pudding or Ochre Jelly causes them to split into two oozes, instead of doing damage.

[Cikomyr2]

Flames of Phlegethos is best used by someone who fights primarily with Green Flame Blade anyway

[Greywander]

Flames of Phlegethos is best used by someone who fights primarily with Green Flame Blade anyway

Yeah, it's certainly not bad on something like an Artillerist, but I'm reconsidering if I'd rather get a different feat instead, probably Fey Touched. For some reason, it just feels like I'm wasting something by not getting the racial feat, even though I don't feel that way about most other racial feats (most of them aren't very good, IMO). I can still get Infernal Constitution, which isn't super optimal either, but the resistance is nice and should come up from time to time.

[stoutstien]

Yeah, it's certainly not bad on something like an Artillerist, but I'm reconsidering if I'd rather get a different feat instead, probably Fey Touched. For some reason, it just feels like I'm wasting something by not getting the racial feat, even though I don't feel that way about most other racial feats (most of them aren't very good, IMO). I can still get Infernal Constitution, which isn't super optimal either, but the resistance is nice and should come up from time to time.

Infernal Con is interesting because it has so many different mitigation perks and in certain campaigns or settings is a noticable boost.