I think no matter how finely we try to tune this, there's still going to be situations where it just comes down to eyeballing it at the time.
Definitely. In fact, if Appendix E has taught me anything, it’s that eyeballing it is the only sane thing one can do when allocating the xp value of any monster.
My head. I made those numbers up as examples to show what I was talking about with damage thresholds.
Draining blood miiiiiight be covered by the "ability loss" EAXPB (see below) depending what game-mechanical effects the loss of blood inflicts. But if it just does continuing hit point damage (a la what a locked-on Stirge does) then the ability loss piece doesn't apply.
Which makes me ask: is there any provision anywhere here for "ongoing damage" giving extra XP? As in, hypothetically, if a monster has an acid attack that does 2d6 damage on a hit and then the acid continues to do d6 damage every round until washed away, what extra XP would that give if any?
Sort of. I’m gonna go out on a limb and say that the "crush" special attack on p. 85 actually means "constriction"*, which appears to establish "continuous damage" as an actual thing in combination with "blood drain".
And then there's the section on "continuous damage" in B/E Expert (p. X27)—which, infuriatingly, includes "swallow".
*) Point in case being that the MM only has the giant sea snake, the strangle weed, and the trapper being able to “crush” things, with the first just crushing “ships”, the second perhaps being an SAXPB, and the third actually also killing victims in 6 rounds, which I’d say makes the crushing a bit of a symptom not really worth anything in addition to the EAXPA for smothering.
As to acid damage, B/E Basic (p. B29) has "Acid" as a "special attack", and then suggests that the gray ooze is worth a "special ability bonus" because it has an asterisk "after hit dice in the monster description" (p. B22, p. B36).
Obviously, Appendix E only confuses things, for it doesn’t even list the anhkheg’s acidic enzymes inflicting 1-4 points of damage per round after it has bitten someone as being worth anything.
Personally, I’ve always treated “continuous damage” as just an SAXPB, unless it leads to “(near) instant death without regard for hit points”, in which case it’s an EAXPA.
I've always assumed the various demonic spell-like effects e.g. generating darkness to be psionic abilities. They're listed like spells in the monster write-ups but they're not spells in that they can't be interrupted or (if your game has such) countered, and therefore shouldn't be the same as ordinary spell use when it comes to giving xp.
Yeah, that's another another tricky one for many reasons. MM lists the demons' ability to generate darkness as an "ability" on p. 16, and then typically goes on to specify things in each separate entry under what I presume one could call "spell-like abilities", despite the fact that that may not really have been a thing in 1977.
Demogorgon can "cast" continual darkness" as part of his array of "spell-like abilities".
Juiblex "is able to shed" a circle of darkness at will; and can then "cause" fear; "cast" a circle of cold; and regenerate hp per melee round; before he (it?) is "also able to" [followed by a list of "spell-like abilities"].
Orcus can "cast" continual darkness as part of its array of "powers".
The succubus can "cause" darkness before the text goes on to list her "spell-like abilities" under "the following feats".
And so on.
I think the (2E?) distinction between "spell-like abilities" vs "casting spells" wasn't really a thing at first. Monsters just had certain "powers" allowing them to do things, with the effects of some of these based on "spells"; others on..., um, nothing (Juiblex' circle of cold); and others on magic items, especially fear, gaseous form, and (create) illusion(s)
(e.g., "cause fear (as wand)"). That's what gonna make doing the various ways Appendix E deals with (magical) effects generated by monsters such a pain in the proverbial.
Also, I guess that whether the demons' ability to generate darkness is a psionic ability or not depends on when psionics became a thing before Eldritch Wizardry was published. Is the mind flayer in The Strategic Review. Vol. 1, No. 1 (1975), the first to mention something akin to psionics? Or is it based on the ubiquitous "telepathy" that starts appearing in Monsters & Treasure--and, once again infuriatingly, is defined as "see ESP" in the DMG Index (p. 235)?
I've never used (and, frankly, never really understood) the psionics system as presented in the PHB; but I do have psionics in my game (using a homebrew system starting from the Deryni books, MM demons, and Mind Flayer abilities) and expanding from there) and they often can and do affect non-psyonics. Thus, I have to account for them in xp calculations.
Another example is the Coffer Corpse (or whichever undead it is, I forget right now) that can teleport people to random nearby places. That's not a spell, in that it doesn't cast and thus cant be interrupted, nor is it psionic - the creature just does it, and thus it should be worth more xp than if it had to go through the interruptable motions of casting a spell to achieve that effect.
In this light, there's an interesting section on "special attacks" in B/E Basic (p. B29), which has "Charm" as a "special attack" in its own right. That seems to make a distinction between a monster using some form of "charm" as a special attack and one actually casting "charm person" or some variant?
Even Appendix E sometimes makes distinctions like that in some form or other
(e.g., dryad, barbed devil).
