Does Darkness dispel Luminous armor?

Question

The spell Darkness (PHB p. 216) reads:

Darkness counters or dispels any light spell of equal or lower spell level.

In our last session a drow used his Darkness spell-like ability against the Luminous armor spell (BoED, p.102) of a PC.

Luminous armor does not have the light-descriptor, which seems to preclude Darkness negating it. But Luminous armor reads:

Luminous armor sheds light equivalent to a daylight spell and counters darkness spells of 2nd level or lower with which it comes into contact.

What does "counter" mean in this case: Does Luminous armor negate the darkness effect and remain active? Or do Luminous armor and Darkness negate each other?

Answer 1

Luminous armor isn't a light spell

First, "[s]pell-like abilities cannot be used to counterspell, nor can they be counterspelled" (PH 180). Assuming something enables the drow to counterspell with a spell-like ability anyway, a drow that readies an action to counterspell then successfully identifies the foe's spell as the luminous armor spell still cannot counterspell it with the drow's darkness spell-like ability because the 2nd-level sanctified spell luminous armor [abjur] (Book of Exalted Deeds 102) lacks the descriptor light.

Likewise, the drow's darkness spell-like ability can't dispel the spell luminous armor once the foe casts it. The 2nd-level spell darkness [evoc] (Player's Handbook 216) and similar spell-like abilities simply have no power over the luminous armor spell absent it having the light descriptor.

What may happen

The luminous armor spell itself does have some power over spells with the darkness descriptor: it "counters darkness spells of 2nd level or lower with which it comes into contact" (BE 102). However, what's meant by this is unclear. That description, I think, both erroneously uses counters when it means dispels and erroneously italicizes the word darkness (i.e. like a spell or magic item) instead of leaving it untouched (i.e. like a descriptor). To be clear, countering magic already in effect isn't a thing, but dispelling magic in effect is; and other spells like daylight (see below) affect spells with the darkness descriptor of certain levels not, for example, spells with the word darkness in their names.

With that in mind, and using the 3rd-level Sor/Wiz spell daylight [evoc] (PH 216–17) that's referenced by the luminous armor spell as a guide, it seems reasonable to this DM to read the luminous armor spell as acting like the daylight spell with regard to affecting areas of magical darkness except automatically dispelling them instead of temporarily negating them. In other words, in this DM's campaigns, a creature wearing luminous armor dispels any magical darkness effect of 2nd-level or lower upon the luminous armor's wearer entering that area of magical darkness. Other DMs may rule differently, though, so it's a good idea to ask ahead.

Answer 2

Darkness interacts with light spells in one of three ways:

1. It can counter a light spell. This requires using the counterspell action, and doesn’t actually cast darkness. Instead, you expend your darkness spell (or spell slot from which you could cast darkness spontaneously) to power the counterspell. If you cast darkness, you haven’t used it to counterspell, and so that part of darkness doesn’t apply to you.

   But luminous armor is not a light spell, and in any event, spell-like abilities cannot be used to counterspell. So neither the target not the ammunition was suitable in this case.

   (As for luminous armor claiming to counter darkness spells it comes in contact with, that would be the reverse operation anyway—but really, I think that has to be seen as yet another instance of shoddy editing in Book of Exalted Deeds. It should use “suppress” or “negate” here. “Counters” is nonsense.)

2. Darkness can dispel a light spell. As the official-but-not-a-rules-source Rules of the Game article admits,

   The rules aren't very clear about what happens when opposing spells dispel each other.

   However, by analogy to the counterspell rules, the most sensible thing here is to rule that a spell that “dispels” another spell can be cast in an alternate mode, where it is like dispel magic that only targets that one effect, but is always successful.

   But just like you couldn’t counterspell with a spell-like ability, you shouldn’t be able to dispel. And luminous armor is not a light spell to begin with.

3. Magical light and darkness can cancel each other out—but again, these rules are unclear. Luminous armor can cancel out areas of darkness from the same or lower-level spells, including darkness. Darkness can suppress light from lower-level spells. Both of these are effects of the actual spell effect, so they apply when cast as a spell-like ability. And the rules are vague enough that maybe, just maybe, the lack of light descriptor on luminous armor is not fatal.

   If we rule that way, and if luminous armor is brought into an area of darkness, the light from the luminous armor is suppressed by the darkness. Luminous armor has the same effect on darkness, however, so what you end up having is an area that is neither illuminated nor darkened by these spells, and just stays at its natural light level.

   In no event does this have any effect on the actual armor from luminous armor.