Adding Vulnerability

[Nifft]

D&D 5e has rules for damage vulnerability, damage resistance, and damage immunity.

Two of those are well represented in the Monster Manual.

One is not.


Let's talk about which monsters could gain vulnerability, and to which damage types would be the most appropriate.

Thunder: Skeletons.

Poison: Monstrous Insects & Spiders, and all non-immune Swarms.

Lightning: maybe some of the weaker Aberrations: Grick, Mimic, Intellect Devourer, Rust Monster?

Acid: maybe stuff that looks like it's made of metal? -- Gorgon, Helmed Horror

Necrotic: maybe Genies & Elemental creatures?

[Zman]

I've been thinking about this very topic too. I've been working on a MM Expansion to go along with my Tweaks and am rewriting some of the entries.

A couple that I've added so far... which is pretty much just the Undead.

Skeltons: Added Radiant and Thunder
Wights: Added Radiant
Zombies: Added Radiant

I've been contemplating others, although I haven't gotten around to adding them yet. I'll just give a rundown through the MM as it coincides with my current project anyways.

Aboleth: Vulnerable to Psychic
Angels: Immune to Radiant, Vulnerable to Necrotic
Animated...: Vulnerable to Acid
Azer: Vulnerable to Cole
Banshee: Vulnerable to Radiant, Psychic
Death Tyrant: Resistant to Cold, and Piercing, Vulnerable to Radiant, Thunder, Bludgeoning
Blights: Vulnerable to Poison
Cambion: Vulnerable to Radiant
Coutal: Vulnerable to Necrotic
Crawling Claw: Resistant to Piercing, Vulnerable to Radiant, Bludgeoning
Death Knight: Resistant to Cold, Vulnerable to Radiant
Demi Lich: Resistant to Cold, Vulnerable to Radiant
Demons: Immune to Necrotic, Vulnerable to Radiant
Devils: Immune to Necrotic, Vulnerable to Radiant
Dracolich: Immune to Necrotic, Vulnerable to Radiant
Elementals: Air Immune to Thunder and Lightning, Vulnerable to Fire, Earth is Resistant to Force, Vulnerable to Thunder, Fire is Vulnerable to Cold, Water is Vulnerable to Cold?
Ettercap: Resistance to Poison
Flameskull: Vulnerable to Bludgeoning
Fungi: Resistant to Thunder, Vulnerable to Slashing
Galab Duhr: Vulnerable to Thunder
Gargoyle: Resistance to Cold, Lightning, Fire, Vulnerable to Thunder
Genies: Dao Resistant to Bludgeoning
Ghost: Vulnerable to Radiant, Psychic
Ghouls: Resistant to Cold, Immune to Necrotic, Vulnerable to Radiant
Giants: Cloud Resistant to Thunder, Lightning; Fire Vulnerable to Cold, Frost Vulnerable to Fire,
Glibbering Mouther: Vulnerable to Psychic?
Golems: Clay Resistant to Bludgeoning, Slashing, and Piercing, Force Vulnerable to Fire:; Flesh Resistant to Bludgeoning, Slashing, and Piercing, Force; Iron Resistant to Bludgeoning, Slashing, and Piercing, Thunder, Force Vulnerable to Cold, Lightning; Stone Resistant to Bludgeoning, Slashing, and Piercing, Fire, Force, Vulnerable to Thunder
Grell: Vulnerale to Psychic
Hell Hound: Resistant to Necrotic, Vulnerable to Radiant
Helmed Horror: Resistant to Fire, Lightning
Homonculus: Resistant to Piercing, Slashing, Vulnerable to Bludgeoning
Intellect Devourer: Vulnerable to Psychic
Invisible Stalker: Resistant to Thunder, Lightning, Vulnerable to Fire
Lich: Immune to Necrotic, Vulnerable to Radiant
Magmin: Vulnerable to Cold
Mephits: Dust Resistance to Thunder, Lightning; Mud Resistance to Bludgeoning, Piercing, and Slashing; Smoke Vulnerable to Cold; Steam Vulnerable to Cold
Modrons: Vulnerable to Thunder, Resistant to Psychic
Mummy: Resistant to Cold, Vulnerable to Radiant
Myconid: Resistant to Thunder, Vulnerable to Slashing
Naga: Bone Resistant to Necrotic, Piercing, Vulnerable to Radiant, Bludgeoning
Nightmare: Resistant to Necrotic, Vulnerable to Radiant
Nothic: Vulnerable to Psychic
Oni: Resistant to cold; bludgeoning, piercing, and slashing from nonmagical weapons
Oozes: Resistant to Piercing, Vulnerable to Fire....

And that was all I had time for there.

One thing I am heavily considering is Vulnerability to Poison for Tiny Creatures, Resistance to Poison for Huge Creatures, and Immunity to Poison for Gargantuan Creatures.

[mephnick]

I think Vulnerabilities need to be handled a lot more carefully than the other two which is likely why they're so rare. Resistences and Immunities can be worked around by players,(hell DMs are so horny about handing out magic items past level 5 that B/P/S resistence might as well not be a thing), but Vulnerabilities basically end a combat if keyed upon. It's a hell of a lot easier to capatilize on a vulnerability in 5e than it is to be shut down by a resistance even though the seem like they should be equal opposites.

[Arvin Natsuko]

I didn't take a exhaustive at the list, but a quick view show that undeads get a LOT of vulnerabilities to radiant. I know it seems thematic, but creates an issue with the Cleric and the Paladin. Both already have good matchup against undead. With those new vulterabilities... it might be a problem. Imagine the smite damage... oh lord, the horror huehue

Edit: Same problem with Demons, Devils and the Pally.

[Nifft]

Thinking about incorporeal undead, they're mostly about regrets and sorrow and the inability to move on.

I feel like vulnerability to Psychic is a better fit than Radiant.

Except for shadows. Shadowy undead should totally be vulnerable to Radiant (and not Psychic).

[MrStabby]

It does kind of screw the balance a bit in favour of those who can chose from a wider variety of damage types (read: casters) and against those stuck with a choice of two or three types.

[Chugger]

Rather than a blanket all-the-time happening vulnerability for creatures x, y and z, what about an adventure specific vulnerability?

Like there is no way these low lvl guys are gonna clear out those wights over there. But there's a pixie nearby who, if they do him a challenging favor, will zap the wights with a special dust he's created that makes them vulnerable to all melee damage for 1 minute. Or radiant damage for 1 minute. Or w/e.

That's kind of a stupid place-holder example. A more "logical" example (one that feels less random and kludged together) might be an NPC who can cast a special freezing cone spell that only does a little damage but makes the monsters "brittle" for 1 minute and vulnerable to bludgeoning damage. I still - still - from the daze of old AD&D - carry a bludgeoning weapon if possible because skels used to take half damage, iirc, to slashing and piercing - but not blunt. And skels were common. In 5e they got bludg. vuln.

Anyway, one-time-charlies for special case vulns could be colorful - could make an adventure feel more epic - could help the party feel they earned the perk by helping the other creature that grants the vuln effect they need, and so on. If you go adding vulns willy-nilly to the MM you might not like what happens. Parties are already too powerful in 5e as it is.

[Zman]

I think Vulnerabilities need to be handled a lot more carefully than the other two which is likely why they're so rare. Resistences and Immunities can be worked around by players,(hell DMs are so horny about handing out magic items past level 5 that B/P/S resistence might as well not be a thing), but Vulnerabilities basically end a combat if keyed upon. It's a hell of a lot easier to capatilize on a vulnerability in 5e than it is to be shut down by a resistance even though the seem like they should be equal opposites.

I completely agree. Vulnerability, especially if it's easy to come by etc needs to put downward pressure on CR.

And yeah, DMs hand out magic weapons like candy! My party is lvl5 and has a single +0 shortsword with a crit ability. DMs need to make them special.


I didn't take a exhaustive at the list, but a quick view show that undeads get a LOT of vulnerabilities to radiant. I know it seems thematic, but creates an issue with the Cleric and the Paladin. Both already have good matchup against undead. With those new vulterabilities... it might be a problem. Imagine the smite damage... oh lord, the horror huehue

Edit: Same problem with Demons, Devils and the Pally.

Oh yeah, my list has problems and Radiant is the crux of it. If I were to implement those changes I'd need to tone down Paladins, at least remove the bonus d8 Radiant vs Undead and fiends as that'd be built into the MM. I'd also make it so Smite damage weren't doubled on a crit, or make smites be declared before you roll to hit, only expending a spell slot on a hit. That should fix the Paladin problem. Cleric isn't nearly as bad. Plus, both should be potent against undead.


It does kind of screw the balance a bit in favour of those who can chose from a wider variety of damage types (read: casters) and against those stuck with a choice of two or three types.

Yes, but most of the time casters aren't strong because they deal damage, they are strong because they control the battlefield. Seeing a moderate level wizard chucking out chromatic orbs seems ok, they could be casting Black Tentacles or Banishments.

[Nifft]

It does kind of screw the balance a bit in favour of those who can chose from a wider variety of damage types (read: casters) and against those stuck with a choice of two or three types.

Nah, that's easily fixed.

Just add a few instances of vulnerability to Slashing, and some to Piercing, and a few more Bludgeoning.

Everyone should get a chance to enjoy.