[RPG] How dangerous is exhaustion

balanceconditionscr-calculationdnd-5emonster-design

I'm interested in adding exhaustion effects to monsters. I might homebrew changes to the exhaustion mechanic, but for now, I'm interested in assessing how dangerous it is if monsters can cause RAW exhaustion.

Related questions:

There is this question about causing exhaustion:
Are there any ways to force levels of exhaustion onto another creature?

There is question about removing it:
Ways to remove exhaustion

And this question about making a spell causing it: What level should this exhaustion-causing spell be?

Considerations

  • When looking at exhaustion (mostly from a combat perspective), the first two levels of exhaustion seem rather benign. The 3rd and 4th have a high impact on combat performance. By 5th level one is basically done for.

  • The linked question above about removing exhaustion shows that this is a hassle.

  • There are apparently no official monsters with such an effect. Though, there is the accursed defiler from Kobold Press's Tome of Beasts which is not official but at least playtested.

Question

How can I account for an exhaustion effect when balancing a monster (e.g. in determining CR)? Assume a monster with one attack per turn which after dealing damage asks for a saving throw to avoid one level of exhaustion.

I assume this would have a high impact, so I would also consider adding it as an x/day attack instead or capping the exhaustion stacking at level 3 or 4.

If you have good reasons to say this is a bad idea, please tell me as well.

Best Answer

This is hard to balance

Similar to the exhaustion-causing spell you linked, such a feature is hard to balance. The problem is that it stacks in a way that gets exponentially worse.

To clarify what I mean: if the encounter is against one of such monsters, the exhaustion-effect is mostly harmless, as the encounter is likely to end before the creature can apply 4+ levels of exhaustion against someone. If the encounter is against six of such monsters, the effect may kill a character that is way higher leveled than the monsters, depending on some luck on the initiative rolls and attacks/saving throws.

Monsters with similar consequences are the Shadows or the Intellect Devourer, which have effects that reduce an attribute and cause insta-death when the attribute gets to 0 (Str and Int, respectively) 1. Both the mentioned monsters are topic of talk in forums due to their seemingly strange balance, with many people complaining they should have higher CRs. For example, How the hell are shadows CR 1/2?!

That said, from the CRs given to these monsters, it seems the devs considered the effect to be minor, and redirected the responsibility on balancing these monsters to the DMs using them (it is pretty much agreed that if you use these monsters as "just another monster of CR X", you are going to TPK your party).

Another monster that may be useful for comparison is the Night Hag, which has an effect that stops a creature from gaining the benefits of resting - effectively implying one level of exhaustion due to lack of rest, but also other problems (no HP recovery, no spell slots recovery, no feature recovery whatsoever). Again: the DMG does not clarify how the Nightmare Hunting feature changes the CR of the Night Hag, though, if at all.

So, in short: When designing the monster, it's likely that the feature will have a very minor impact, however, when designing the encounter, the DM will have to be extremely careful on how many monsters they are putting, at what situation (i.e., will the adventurers get any rest soon, or is this the first encounter and the party will be playing with a harsh disadvantage for the remaining of the day?), etc.

By the way, one major difference from the features I mentioned is that exhaustion only gets cleared one level at a time. However, there is precedent in the Exhaustion from Dashing (under the Chase rules in the DMG) to make it a "special exhaustion" that has all of its levels cleared in a rest, rather than just one.

So, to conclude: you will have to extensively playtest such a monster, as no guideline is given to anything similar, and theoretical balancing is considerably hard.


1 The intellect devourer doesn't actually kill the creature just by getting the int to 0, but then it can use its Body Thief feature, effectively killing it.