Completely Exhausted!
Apparently there is this mechanic in 5e called “exhaustion” that takes effect when…reasons. I don’t really know beyond “falling unconscious” triggers the effect. I’m only aware of the mechanic because I read a play report regarding a desert chase scene an adventuring group undertook while in bad, bad shape, which exhaustion only made worse (slower movement, inability to spend or regain HD, etc). The idea intrigued me, as it seemed to add a level of tension to play that simple hit point loss does not.
My understanding is that there are levels of exhaustion, from one to five. The first level of exhaustion doesn’t seem to have a huge effect, but level five means you can’t move, defend yourself, cast spells, use HD, or regain hp, or pretty much act in any way until you bring down your exhaustion level with a full night of rest (healing spells don’t help).
My inclination is not to add this as a constant mechanic to the game, but to add it as a sparingly utilized mechanic for tense, long-term situations — wilderness treks, pursuits, moving through extreme environments, failure to take regular long rests, severe injury and unconsciousness, and so on — and to have only three levels of exhaustion, from “tired, but fully capable” to “halved movement, penalty to all actions” to “completely incapable”.[1]
Healing in my D&D hack works as follows: a short rest lets a character spend any number of their hit dice to heal hit point damage up to whatever they roll on those dice. Once those HD are used, they can’t be used until they are restored by a long rest. After a long rest, a character regains half their used HD, rounded down. Long rests do not restore hit points. I felt this was probably a pretty good mechanic to tie to Exhaustion as well.
In addition to hit point damage, adventurers may suffer from Exhaustion, a state of extreme tiredness and weariness the DM can use (sparingly) to add tension to situations such as wilderness treks, pursuits, and so on. Some examples are strenuous physical exertion (not necessarily combat, but certainly a long and brutal combat), sustained travel through extreme environments, failures to take regular long rests, and being severely injured and knocked unconscious. (I include this last only as a measure to avoid the common situation of a character being savagely beaten and popping right back up, ready to go after being battle-field tended by a healer or a little magic.)
There are three levels of Exhaustion, from “just tired, but still fully capable; you need to rest” to “halved movement, penalty to all actions; you need to sleep” to “completely incapable; you are asleep.”[2]
A level one Exhaustion is removed after a successfully completed short rest. A level two or level three Exhaustion must be removed with a long rest. In dangerous areas where rests can be interrupted, Exhaustion remains until an appropriate rest is successfully completed — making a well-defended base camp important during long adventures.
Exhaustion cannot be removed or healed with low-level cure spells like Cure Light Wounds. Higher level healing like Cure Serious Wounds will remove a level one Exhaustion, and Heal will fully reinvigorate any character.
- Level one Exhaustion causes no particular ill-effects. It can be cleared by taking a short rest. The danger here is in continuing to engage in strenuous activities.
- Level two Exhaustion results in all rolls being made at disadvantage, Movement rate being halved, and Hit Dice being unavailable for healing (or other tasks).
- Level three Exhaustion causes the above penalties and the character becomes mostly unresponsive: they can not move, cast spells, and so on, and require three successful, non-consecutive Survival checks to in order to recover.
[1] Note that these are untested rules, and more a thought-experiment of how I might include Exhaustion as a mechanic.
[2] I had originally considered including five levels of Exhaustion, but upon further cogitating realized the impact on play of tracking yet another fluctuating statistic with a more finely-grained set of penalties felt over-indulgent and sacrificed quick, interesting play for the sake of psuedo-realism.