D&D 5E Swapping out Heat Metal for Magma Mephits

[FireLance]

I'm working on a solo adventure for a paladin PC and I think that magma mephits would be way too effective as their ability to cast heat metal basically means the PC takes 2d8 fire damage every round, no save, until the mephit loses concentration or dies.

I'm thinking of replaing heat metal with a fire version of Melf's acid arrow (call it magma blast): ranged spell attack, effectively 6d4 fire damage on a hit, 2d4 fire damage on a miss.

The question is, should I change the magma mephit's CR from 1/2 to 1/4? On the one hand, it is now less effective against PCs wearing medium or heavy metal armor (but more reasonably effective, IMO). On the other hand, Melf's acid arrow is also a damage dealing spell of the same level as heat metal, so it shouldn't change the CR.

What do you think?

 

[Fenris-77]

How many Mephits are we talking about versus what level of Paladin?

 

[Shiroiken]

What level is the paladin? Solo encounters are always tricky for the solo character, since even 3 creatures are often an overwhelming force due to the difference in action economy (this is why non-legendary solo monsters do so poorly). A 1st level paladin facing 1 magma mephit would entirely come down to 2 dice rolls: initiative and the 1st heat metal damage (the 2nd won't matter, as it will almost certainly drop the paladin or the mephit will be dead). If the paladin goes first, they can hurt/kill the mephit, and even if they use the heat metal the paladin should hopefully kill/disrupt the mephit, unless really high damage is rolled (dropping the paladin outright).

 

[bedir than]

What would changing the CR do?

 

[cbwjm]

You could just not use it, especially if there are more than 1 magma mephit. I have no idea about the paladin's stats, but they generally aren't known for their dexterity or ranged so they might be likely to take full damage from the mephit's flame breath and explosion (even with 10 dexterity the chance is 50/50). The breath and explosion from a couple of mephit's could be quite punishing without the addition of heat metal.

 

[FireLance]

How many Mephits are we talking about versus what level of Paladin?

What would changing the CR do?

Let's say 3rd level, so based on encounter guidelines, a standard encounter should be with one CR 1/2 creature or with two CR 1/4 creatures.

Anyway, take heat metal out of the picture. I've already decided to replace it with a fire version of Melf's acid arrow. I'm just wondering if the swap should change the magma mephit's CR.

 

[jaelis]

Anyway, take heat metal out of the picture. I've already decided to replace it with a fire version of Melf's acid arrow. I'm just wondering if the swap should change the magma mephit's CR.

Probably not, they are both the same spell level and have similar baseline damage. Heat metal is just swingier, in that it is much more effective against an armor-wearing foe and less against a creature with no equipment.

That said, Melf's is pretty weak for a 2nd level spell. You could use scorching ray as a base instead. Or an upcast flaming hands.

 

[FireLance]

That said, Melf's is pretty weak for a 2nd level spell. You could use scorching ray as a base instead. Or an upcast flaming hands.

I did think about using scorching ray, but I thought Melf's acid arrow, with its initial and secondary damage on a hit, fit the narrative of being hit by magma better.