[RPG] Are hit points non-fungible

dnd-5ehit-pointsmagic-items

There are many effects in D&D 5e which reduce a target's maximum hit points. Take for example, the Vampire's bite which contains the following rider:

The target's hit point maximum is reduced by an amount equal to the necrotic damage taken.

This phrasing is relatively easy to understand and is consistent with the rest of 5e's hit point definitions.

Now let's look at the Sword of Wounding. Its description has interesting implications when you consider the first sentence:

Hit points lost to this weapon's damage can be regained only through a short or long rest, rather than by regeneration, magic, or any other means.

The phrasing for this effect is very different from other similar effects such as the aforementioned Vampire's bite as it targets specific hit points. While this makes sense in concept and fantasy (the wounds inflicted by this sword are not easily healed), I find myself scratching my head when thinking about how this works in practice.

For example, let's say that a Troll has lost all but 15 of its hit points to varied (nonmagical) sources of damage. When those 15 hit points are subsequently lost to a Fighter wielding a Sword of Wounding, can the Troll use its Regeneration to return to 10 HP? I can see two different scenarios here:

  1. Option 1 (non-fungible hit points): its "first" 15 hit points have been lost and can't be regained. Because these can't be regained, no subsequent hit points can be regained and the Troll remains at 0 HP.
  2. Option 2 (fungible hit points): the "un-healable" hit points effectively function as a maximum hit point reduction, and the Troll regenerates back to 10 HP. On subsequent turns, its total hit points cannot exceed more than [its max hp – 15].

Are there any official sources which indicate how this works? Specifically, I'm interested in understanding whether hit points are fungible (i.e. they can be regained independently from one another) or otherwise.


Some additional, opinion-based context: D&D is fundamentally a story-based game, so thematically, there's a lot of wiggle room for how this can be interpreted while remaining within the bounds of hit points as a concept. Option 1 fits with the idea that taking the last hit points constitutes the "killing blow". Option 2 fits with the idea of "death by a thousand cuts" (the other wounds can be healed to stave off death). The spirit of this question is basically asking whether the Sword of Wounding canonizes one of these interpretations, and asks if there are other rules which provide more clarity around this.

Best Answer

There are no hidden rules. HP are fungible.

Given the possible interpretations, in the absence of any text that forces us to pick the more complex interpretation, we should default to the simpler reading. We should not go out of our way to invent additional assumptions which the rules do not require in order to be coherent. (You may be familiar with this concept as "Occam's Razor".)

There are no rules that state or imply that HP are non-fungible. That is to say, all hit points are identical and interchangeable; there isn't an order to them. Your "last" HP isn't special or different from the others. We should not accept your Option #1 unless there is some specific rules text that supports or requires it, and since that text just doesn't exist, we're left to default to Option #2.

HP lost to a Wound can't be healed, but any HP lost in other ways can be, so the Sword of Wounding's damage can't "lock off" the rest of your HP. If your last HP was lost to a Wound, you can still heal all the other HP you have that weren't caused by Wounds, whether that healing comes from troll regeneration or a cure spell.

So yes, Sword of Wounding damage works kind of like reducing maximum hit points (though it does not, technically speaking, actually change your max HP). Why is it worded differently from the Vampire's ability? We can't say. But we can be aware that different books (and often different sections in the same book) are written by different authors, edited by different editors, and often not cross-checked to see if they're using consistent language.