Vulnerabilities: an underutilized mechanism?

Well, since I was a bit bored I decided to make list of all the different energy types the various classes had access to.

However, having done that, I realized that it doesn't really matter much either way as long as the class has access to untyped damage which is really the single best damage type you can get because all of the energy damage types can be resisted by monsters (or even worse they can be immune).

4e monsters can have 'resist all' or 'resist <energy type>', but there's no equivalent to 'resist untyped'. Why is that? E.g. iron golems are an example that definitely should have that kind of resistance.

There is also insubstantial but it applies to all damage types equally.
Why this gap in design space?

The only reason to choose an energy type over untyped damage are monster vulnerabilities, as far as I can see. The problem is: (with the exception of radiant) they're totally underused!

Looking over MM1 and MM2, these are the vulnerabilities I found:
- undead, green slime & myconid: radiant
- eladrin & firbolg: necrotic
- treant & green slime: fire
- magma beast, phoelarch & water archon: cold
- fell taint & dimensional marauder: psychic

There's also a few odd ones:
- flux slaad: variable
- lycanthropes: silver
- swarms: close & area attacks
- troll: not described as a vulnerability though it should be: acid & fire

I'm sure I missed some, but still: except for the undead (of which there are hundreds), that's not many. And even those that exist sometimes don't do much, e.g. they may just cause the monster to be slowed for a turn.

Now, this might stray into house-rule territory, but I'd really like to see more monsters with vulnerabilities to make the different energy types more appealing.
I am sort of thinking about reversing resistances: make a monster vulnerable against everything it isn't resistant or immune to.
While immunities and resistances may (partially) negate some of your powers, vulnerabilities may make them more effective, i.e. it's actually an anti-grind mechanism.

Have you been doing anything like this?
Or how would you modify monsters to give them more vulnerabilities (ideally without changing their threat level)?

Yeah, I've thrown vulnerability to x on a number of monsters that I've designed for 4e. One of the cool things to do is instead of just making it "vulnerable 5 lightning" (f'rex), you can make it "vulnerable lightning: when this creature takes lightning damage, it is also slowed/dazed/slides 3/etc".

Adding more vulnerabilities is cool, because it reduces grind (as you noted) and it also gives pcs something to clue in to to make a battle easier.

I actually like vulnerabilities that do more than add additional damage; I find them more tactically interesting, even if only inflicts the slowed condition, for example.

I too was disappointed by the under use of resistance/vulnerabilities in 4e.
Since first reading the 4e monster manual I've wondered why 'weapon' wasn't a damage type so that monsters couldn't have resistance/vulnerability to it.
The closest thing is the grick which resist attacks vs. AC.

Particularly surprising given in 3e how common DR was, with resistances being less common, 4e has reversed the situation to a great degree.

So yeah, I've added vulnerabilities to some monsters, often some special effect (I really like the jester's idea of forced movement) instead of or in addition to extra damage.
And occasionally I have even used resist/vulnerability (weapon) damage.


I'd advise against adding too many vulnerabilities (such as EVERYTHING it isn't resistant to) probably would make fights too easy and it wouldn't really make monsters more interesting.

Instead add perhaps one (or two if it has many resist/immunities) vulnerability to each monster you use. And let the PCs figure it out with knowledge checks (minor action) or by trial and error.

I rebuild practically all my monsters in the Monster Builder before use and adding vulnerabilities and increasing resistances is one of the first things I do.

I particularly like adding a vulnerability to cold to reptilian creatures such as yuan-ti. Rather than taking more damage, the yuan-ti is slowed.

Similarly, IMC all insubstantial undead have a vulnerability to radiant damage that ignores the insubstantial quality.

My frost giants and white dragons are vulnerable to fire damage and my fire giants and red dragons are vulnerable to cold damage, but their resistances to cold and fire, respectively, are much higher.

I think it was Mike Mearls among the designers that stated his preference to do away with immunities, resistances and vulnerabilities. I avoid this like the plague. I like to reward clever play and I also like the verisimilitude that, for example, a great flaming hellhound is not exactly bothered by the wizard's fireball spell.

The problem with vulnerabilities and resistances is that it is difficult to balance, specially in a general way, such as in the MM.

But each DM providing such resistances and vulnerabilities, seems a more sensible approach, since they have a clear picture whether that would be unbalanced or not.

Derulbaskul said:

I think it was Mike Mearls among the designers that stated his preference to do away with immunities, resistances and vulnerabilities.

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If I recall correctly, Mike Mearls' statement was about wanting to do away with immunities, resistances, and vulnerabilities as they are and instead have them be more along the lines of having effects rather than simple additional damage or damage reduction. (i.e. you hit the hellhound with fire and it will recharge his breath weapon, you hit the hellhound with cold and it will slow him)

but i'll have to hunt around for that quote to make sure I'm even remembering correctly (or perhaps attributing it to the wrong designer if it wasn't Mearls)

fba827 said:

(snip) (i.e. you hit the hellhound with fire and it will recharge his breath weapon, you hit the hellhound with cold and it will slow him) (snip)

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I do like part of that idea: but I would also, IMC (thus IMO and YMMV), not have that hellhound take damage from the fire-based attack.

Derulbaskul said:

I do like part of that idea: but I would also, IMC (thus IMO and YMMV), not have that hellhound take damage from the fire-based attack.

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...

That's just freaking mean.

To compare notes, how many TPKs have you had? I'm up to 9 with 8 near TPKs (one survivor).

ValhallaGH said:

... That's just freaking mean. To compare notes, how many TPKs have you had? I'm up to 9 with 8 near TPKs (one survivor).

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None.

My PCs have no many ways to survive it is not funny (actions points, of course, plus luck points for every session [these let you have re-rolls] and fate points [one per level, can be used to avoid death]).