D&D 5E Heat Metal Rules Interp / Minor Nerf

[discosoc]

It does sound like heat metal is more powerful in the hands of NPCs than PCs. However - didn't WotC build these monsters, and determine their CRs, by what their damage output was? It seems that a wizard with fireball is a different CR than a wizard of the same level with dispel magic. So, hypothetically, the lizardfolk shaman should have been balanced on the assumption that "he has a killer spell available".

The monster manual states that spell selection is one of the easiest and quickest ways to customize a monster (other than armor and weapon swaps), and doesn't change the CR at all (assuming you're swapping for same-level spells).

 

[Shadowdweller00]

I haven't found Heat Metal to be an issue at all; which is kind of ironic given that the spell imposes damage and unavoidable disadvantage against the right foes. The issue is one of opportunity cost...given that Heat Metal is single target and requires concentration. Multi-target and/or battlefield control spells of comparable level just end up being much more powerful for both PCs AND NPCs under most circumstances. The lizardfolk shaman, for example, gets Conjure Animals - which is much more of a threat against the PCs. Against NPCs, things like Spike Growth or even flaming sphere end up being more universally effective (at least for druids - I have a bit less experience with bards - but even there concentration comes at a premium).

 

[Shadowdweller00]

The monster manual states that spell selection is one of the easiest and quickest ways to customize a monster (other than armor and weapon swaps), and doesn't change the CR at all (assuming you're swapping for same-level spells).

Spell selection changes CR if it changes the monsters' maximum damage output, as per the rules in the DMG.

 

[discosoc]

Spell selection changes CR if it changes the monsters' maximum damage output, as per the rules in the DMG.

And in the customizing NPC's section of Appendix B in the Monster Manual, it states "One way to customize an NPC spellcaster is to replace one or more of its spells. You can substitute any spell on the NPC's spell list with a different spell of the same level from the same spell list. Swapping spells in this manner doesn't alter an NPC's challenge rating."

As far as I can tell, what you're referencing is the "Innate spellcasting and spellcasting" section of DMG that deals with creating a new monster. Even there, it doesn't specify anything about 'maximum damage output' but rather mentions that if a spell does more damage that it's "normal attack routine" it needs to be considered (normal attack routine being somewhat close to the listed value on page 274). There's no formula to go by that really works according to the MM stats, and even page 82 mentions that CR should always be weighed against the capabilities of the party, especially at low levels.

So I guess my final point is that a very specific spell selection can in fact make an encounter easier or harder, but that's part of the GM's job to identify it when designing the encounter, because every group is different. CR will only take you so far.

 

[Shadowdweller00]

And in the customizing NPC's section of Appendix B in the Monster Manual, it states "One way to customize an NPC spellcaster is to replace one or more of its spells. You can substitute any spell on the NPC's spell list with a different spell of the same level from the same spell list. Swapping spells in this manner doesn't alter an NPC's challenge rating."

The appropriate section about modifying a monster and calculating CR is in chapter 9 of the DMG. Specifically pages 273 through 282 or thereabouts.

Under the heading "Modifying a Monster", p273: "However, once you change the creature's offensive or defensive ability, such as hit points or damage, its challenge rating might need to change as shown later."

It is the clear intent of that section that ANY changes that affect the creature's hit points, AC, or damage output potentially change CR. Even weapon and/or armor swaps.

 

[discosoc]

The appropriate section about modifying a monster and calculating CR is in chapter 9 of the DMG. Specifically pages 273 through 282 or thereabouts.

Under the heading "Modifying a Monster", p273: "However, once you change the creature's offensive or defensive ability, such as hit points or damage, its challenge rating might need to change as shown later."

It is the clear intent of that section that ANY changes that affect the creature's hit points, AC, or damage output potentially change CR. Even weapon and/or armor swaps.

Yes but spells are *always* going to be situational. We can use dispel magic and fireball as an example. If you read it meaning that since fireball is capable of doing damage (increases the damage potential) and dispel magic isn't (does no damage), then you'll have to boost the creatures CR up by something (maybe something, maybe nothing, depending on what it's normal damage is). But the fact is, dispel magic is often going to be much worse for a group to deal with if they have casters.

With the Lizard Folk case, swapping out heat metal for some other 2nd level spell may or may not cause the encounter to be any more difficult. It just depends, which is why trying to focus on the exact numbers for determining CR is silly. Also, as the NPC section in the MM states, spells can generally be swapped out without any issue. Same with armor and weapon selection.

 

[Saeviomagy]

Personally I would recommend swapping it out for moonbeam or flaming sphere, spells which do comparable damage, but can be targeted at anyone or anything. The goal isn't to make them less effective, it's simply to stop one character from being targeted by the same spell in every combat.

 

[Kusodareka]

Thanks everyone for all your replies.
I'm mostly thinking about the spell in terms of power against the PCs.

Personally I would recommend swapping it out for moonbeam or flaming sphere, spells which do comparable damage, but can be targeted at anyone or anything. The goal isn't to make them less effective, it's simply to stop one character from being targeted by the same spell in every combat.

Thanks for this suggestion. I'm going to go with this.
Or follow Majoru Oakheart's suggestion to have a "gentlemen's agreement" to only cast it on weapons.

FWIW, when I pitched the campaign world, I indicated that I did not want the environment to rule out certain character types.
So heavily armored fighters would just sweat a lot, etc. in the heat, without having to roll for heat exhaustion as they probably should. So I don't want the 1 cleric to feel like he's being singled out or forced to take sub optimal armor.

 

[Majoru Oakheart]

I haven't found Heat Metal to be an issue at all; which is kind of ironic given that the spell imposes damage and unavoidable disadvantage against the right foes. The issue is one of opportunity cost...given that Heat Metal is single target and requires concentration. Multi-target and/or battlefield control spells of comparable level just end up being much more powerful for both PCs AND NPCs under most circumstances. The lizardfolk shaman, for example, gets Conjure Animals - which is much more of a threat against the PCs. Against NPCs, things like Spike Growth or even flaming sphere end up being more universally effective (at least for druids - I have a bit less experience with bards - but even there concentration comes at a premium).

It's only really overpowered when NPCs use it against PCs. Enemies normally die so quickly that it isn't broken and most of them don't wear armor.

As for it being worse than those other spells, that's kind of debatable. Conjure Animals isn't as good as everything thinks it is. There's basically one or two animal choices that make it good. If you listen to Mike Mearls and The Sage then the caster isn't supposed to be able to choose the animals they summon. So it isn't that good. Spike Growth, IME has no effect at all. You cast it, all the enemies stand still after the first one takes some damage from it, and they use range weapons on the caster until it goes away. Flaming Sphere only does damage at the end of a round that you are next to it, so anyone will move away from it, thereby taking no damage at all. Basically, it is a single target spell that requires a bonus action every round to attack someone.

If someone is wearing armor, it's one of the most effective spells you can cast. Especially because most of the area of effect spells are not concentration based, so you cast heat metal and then you can fireball all you want afterward.

 

[FormerlyHemlock]

It's only really overpowered when NPCs use it against PCs. Enemies normally die so quickly that it isn't broken and most of them don't wear armor.

As for it being worse than those other spells, that's kind of debatable. Conjure Animals isn't as good as everything thinks it is. There's basically one or two animal choices that make it good. If you listen to Mike Mearls and The Sage then the caster isn't supposed to be able to choose the animals they summon. So it isn't that good.

The bolded line above is the flaw in the argument. Basically all the animal choices are good. A CR 1/4 Draft horse works differently than a CR 1/4 Giant Owl works differently than a CR 1/4 Constrictor Snake works differently than a CR 1/4 Wolf, but they'll all mess up the PCs pretty good if there's eight of them on top of whatever lizardfolk were already there.

Also, Sage Advice doesn't say the caster cannot choose. They say it's up to the DM, which it is. IMG for some spells that means "random tables" (Conjure Fey) or "depends on where you cast it" (Conjure Minor Elementals) or "caster gets to request specific forms" (Conjure Animals), based on the spell description. I let spellcasters request animal forms for Conjure Animals because the spell text makes it clear that these are not actual animals you're summoning, they're fey spirits shaped into animals, and it makes sense that the caster gets to influence the shaping to an extent. But it's still a good spell no matter what you get. Eight elks? Two giant bats, four axe beaks, and two large centipedes? The latter would be more hassle for the DM to run than a homogenous group but it's still over a hundred HP of meat shield. And I didn't even know until typing this paragraph that elks are pretty vicious killers in combat--50' movement plus 13 points of damage plus knockdown is good. The main downside is that elks have have 13 HP apiece, but if your lizardfolk shaman summons eight elks on top of the six lizardfolk warriors that are already there, your CR 5 fight goes instantly from Medium to Deadly, which is a pretty good indication of the impact those elks will have. That's far, far better than imposing disadvantage and 2d8 damage per round on one PC.

If Spike Growth makes the enemy stand completely still, then it is doing its job. (For extra fun, combine Flaming Sphere and Spike Growth! Now "you just move away from the flaming sphere" isn't so simple.)