My instinct is that the skeletons can 'interrupt' the sparks of pain effect and explode but I don't want to just rule this myself and my head hurts too much to sort it out right now.

Sparks of Pain give Aura 4, enough to kill copper level skeletons.
Aura (4)
Each time an enemy figure moves into a space adjacent to a figure with the Aura ability, it immediately suffers 1 (4) wound(s) that cannot be reduced by armor. The Aura ability inflicts no damage when the figure that possesses the ability moves adjacent to an enemy figure.

Captain Bones has an upgrade that allows skeletons to explode damaging adjacent heroes.
Death Head
All of your normal (ie non-master) Skeletons gain the ability to explode. They may do this at any point of their activation for free, dealing one red die of damage (ignoring armour) to all enemy figures in adjacent spaces. Skeletons that explode are instantly killed and cannot be prevented from dying by any means.

I'm inclined to disagree. First, I'm not convinced that exploding is an interrupt effect at all; things that heroes can do "at any time during their turn" (such as spending fatigue, or using Koll's Mark) don't automatically gain interrupt status, AFAIK. And it's pretty weird to think of a figure interrupting its own activation.

But even if we grant that it's an interrupt, precedent is that you can't interrupt part-way through the resolution of a single activity. You can't use a Guard order to interrupt an attack or an overlord card after rolls have been made, for example; you can only interrupt right when it's declared, or after it's over. I'd argue that any effects for entering a square (including Aura, damage from pits/lava, rolling for ice, etc.) are part of the movement, and therefore interrupts can only occur before the movement occurs (while you're still in the original space) or after all effects of entering that space are resolved.

The way Aura works is that as soon as an enemy moves into a space affected by aura, they immediately take the damage. Since Sparks of Pain must be played at the beginning of the overlord's turn, you're not really interrupting anything.

I would say that the Aura effect would happen first.

I would also concur that the Aura affect would be applied first.

Antistone said:

Interrupt may have been a poor choice of word, since it is a de facto game turn.

I remain unconvinced either way (still arguing for the sake of understanding, not because that is my confirmed belief).

It is simply an effect that you can use any time during your activation.
If you can't use it between receiving damage and dying, then why would you be able to use effects that prevent wounds between taking damage and dying? Sure, that is 'obviously' when they are supposed to be used, but really, what is the major difference? There is no specific trigger for these things (and I include Ghost Armour, Skull shield and Exploding Skeletons together here), you can just use them. If you can't use Exploding skeletons when you take damage from moving into a space why would you be able to use Ghost Armour?

Still on the fence.

For the record we tossed a dice and got on with the game with Sparks of Pain providing safe protection.

Kartigan said:

Not just to you, but in general, why?

Corbon said:

Well, when the OL plays a Pit Trap or a Crushing Block on your hero who has 2 hearts remaining, do you allow the hero to spend a movement point to drink a health potion "in response"?

"While I am falling into the pit, I quickly uncork my potion and..."

Obviously not.

Descent is no Magic: the Gathering . You can't interrupt stuff that's happening, except when indicated on the cards . Ghost Armor cancels wounds? You can play its effect between damage calculation and the actual removing of the hearts because the card specifically says so . Same for shields. Similar (but not exactly the same) for a guard order, whose rule specifically says that you can use it between an attack declaration and the actual attack (but not between damage calculation and damage application).

Does Spark of Pains say you can explode your skeleton while it is taking wounds? I don't think so, and if the card doesn't say so, you can't.

That's how I see it in any case.

Ispher said:

Not a good analogy - you can't take a movement action in the middle of another movement action (the resolve an action entirely rule mentioned by Antistone), so drinking a fatigue potion (which is a movement action) is out by the rules.
Sparks of Pain says you can explode "at any time during your activation". If you are taking wounds during your activation, then yes, it does effectively say that you may explode when taking wounds (during your activation).

Ghost armour doesn't say anything regarding timing. Neither does Skull Shield. Neither does Exploding Skeletons - well, actually it does, it says "at any time during your activation" (IIRC).
Spend 1 fatigue to cancel 1 wound being dealt to you. You may use this ability multiple times, paying its cost each time.

Exploding skeletons is effectively a skill (ability actually) that skeletons have - like Pierce. Also like Blessing or Boggs the Rat or... wait for it... Aura (just thought of that).
Skills (and abilities) are available ' at any time ' (DJitD pg 6) - although some have specific triggers or activations.

Other things that are available 'at any time' include the overlord's ability to cards for threat. That can certainly 'interrupt' an otherwise uninterruptable action! Similarly, event and trap cards can be played 'at any time' (if they have a trigger, then it becomes at any time that trigger occurs) - they too can 'interrupt' an action, when appropriate. Spending fatigue can be done 'at any time' (after the hero declares an action) - in the potion example the hero can spend the fatigue for the potion, he just can't drink the potion as that is another movement action and the first action must be completed. But, for example, the hero could move into deep water (maybe fall after rolling badly in a rope swing) and spend fatigue for the potion before spending fatigue for the water cost (taking wounds instead).

However, what I think at the moment is the strongest point, is the fact that both Exploding and Aura are abilities/skills. Both are 'on' (available) at any time. Since both can happen simultaneously (in theory), it should be the active player's choice as to which goes first (there is a precedent statement for this somewhere but I can't remember where).

Corbon said:

One is active, the other is reactive.

Shields and Ghost Armor don't explicitly say "when you receive wounds...", but to cancel a wound "being dealt to you" presumably requires that it be used when there is a "wound being dealt to you" to cancel. There's an implied trigger. Not as rigorous as it could be, but this is Descent, we're lucky that the wording explicitly excludes the possibility of exhausting it in town to cancel a wound received by another hero.

If you want to argue that shields and Ghost Armor are active things that you do on your own initiative, as opposed to being reactive effects, the only way I can see that even being comprehensible is if you treat them as healing (they cancel a wound that you was "being dealt to you" some time in the past) rather than as damage prevention. If you're willing to say that an Iron Shield is a 1/turn healing effect, then I guess I can't make a convincing RAW argument that you're wrong (though the "cannot cancel wounds that ignore armor" clause would be a major pain to track), but I doubt your players will seriously entertain that suggestion.

Corbon said:

The rule for the Aura ability says that an enemy figure immediately takes damage when entering a space adjacent to a figure with Aura. The word immediately implies to me that the Aura takes place right away, and has precedence over any other effect or action, in other words, it happens immediately. The Death's Head ability states that you can detonate a skeleton anytime during its activation, but I would argue it must take place either before or after you enter the space. And if you choose after you've entered a space with Aura, you must take that damage first since the Aura occurs "immediately" after you enter the space, you can't make something happen before it, it has precedence over anything else.

I know that Death's Head nowhere states that it is an attack, but why should attacks work any differently if you ruled that Death's Head came first? Why can't my Beastman move next to you, and make his attack before your Aura goes off? All the rules state is that monsters may make an attack during their activation. Also if you can use Death's Head before you've finished your movement, why can't you make it detonate "between" spaces so that you are adjacent to more figures? State that you are using it as your skeleton is transitioning spots or something.

I realize that both of those are a rather silly examples, but I would still argue that Aura occurs first, due to the wording of the ability.

Corbon said:

I'd argue that "at any point of their activation" isn't necessarily equivalent to "at any time", even during an activation.

When a hero takes a Ready action, "the order may be placed at any time during his turn." (JitD p.8) The wording for when attacks can be made, either for heroes or monsters, is not exactly the same, but doesn't specify any restrictions, either. Would you argue those things can be done between receiving damage and dying from it, too?

Antistone said:

Hmmm, the attacks wording is a bit vague.
...make his attack before, after, or at any point during his movement... is always taken to be at discrete points along the movement but doesn't actually specify.

I don't think that's enough to be convincing though. It isn't as strong IMO as the fact that Aura and exploding are both abilities that are 'on' and the active player gets to choose which goes first. Exploding is not making an attack. Making an attack is unofficially an action, in that an attack once started can't be interrupted except by things that interrupt attacks due to specific triggers. Therefore you cannot make an attack until the movement action (entering the space) has been resolved. But exploding is not the same - it is an ability and is 'always on'. That is all very fuzzy though... and not particularly important because...

...I missed Aura's 'immediately' which I think is enough to be convincing.
If Aura didn't operate 'immediately' (thus taking precedence over other effects happening during that move-into-space-action) then I think there would still be a decent case for exploding first. But since Aura operates'immediately' it must be resolved before continuing on with other effects pertaining to the move-into-the-space action. Aura is resolved, skeleton dies, can't explode.

Thank you for your patience gentlemen.

I agree with Antistone's original response. To me this particular conflict seems pretty clear. When a skeleton explodes it deals damage to targets in adjacent spaces. Thus it must be in a space adjacent to a desired target in order to hit that particular target by exploding. To be in that space, it must first enter that space, and therefore take aura damage. The Aura effect would be resolved first, before the skeleton gets a chance to explode.

Corbon said:

Just for the record, the ruling about choosing the order to resolve things originally was made only for "start of turn" effects, and we on the forum have extrapolated wildly. It's not clear which player should choose the order when more than one player is affected by the results, and I'm not aware of any reason that being an ability or not would have any effect whatsoever (in fact, the standard examples of "start of turn" effects, like Burn tokens and Rest orders, are all NOT abilities).

So far as I know, there is no official ruling that says that the active player chooses the order of resolution of abilities, or anything resembling that.

Antistone said:

Wasn't there something similar for Feats? That is what I was thinking of.

Corbon said:

Well, there's this, from the recent FAQ updates:

Q: Are there any general rules for resolving what happens if the overlord wants to play a card and a hero wants to play a feat card both in response to the same triggering event? Which card is resolved first?
A: The active side has priority.

It still regards reactive effects that trigger off the same event and has even less to do with abilities than the "start of turn" ruling. And it certainly isn't directly applicable to the case in question.

Also, I think this one is really about who has the first opportunity to choose to use an optional power, and not directly about the order of resolving extant effects, since presumably the player with the second card could change his mind and opt not to play it after the first card resolves. That's a subtle and possibly imaginary point, though.

Antistone said:

Well, we now have two distinct operations where the active player gets first option, so the 'wild extrapolation' is slightly less wild.
But both are separate and particular, so it is still 'slightly-less-wild' extrapolation to take them further.