How does Glitterdust interact with Blink?

Question

If an enemy wizard casts Blink, and I try to respond with Glitterdust, what happens? Blink's description reads, in part:

You “blink” quickly back and forth between the Material Plane and the Ethereal Plane and look as though you’re winking in and out of reality at random. Blink has several effects, as follows.

Physical attacks against you have a 50% miss chance, and the Blind-Fight feat doesn’t help opponents, since you’re ethereal and not merely invisible. If the attack is capable of striking ethereal creatures, the miss chance is only 20% (for concealment).

If the attacker can see invisible creatures, the miss chance is also only 20%. (For an attacker who can both see and strike ethereal creatures, there is no miss chance.) Likewise, your own attacks have a 20% miss chance, since you sometimes go ethereal just as you are about to strike.

Any individually targeted spell has a 50% chance to fail against you while you’re blinking unless your attacker can target invisible, ethereal creatures. Your own spells have a 20% chance to activate just as you go ethereal, in which case they typically do not affect the Material Plane (but they might affect targets on the Ethereal Plane).

While blinking, you take only half damage from area attacks (but full damage from those that extend onto the Ethereal Plane). Although you are only partially visible, you are not considered invisible and targets retain their Dexterity bonus to AC against your attacks. You do receive a +2 bonus on attack rolls made against enemies that cannot see invisible creatures.

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An ethereal creature is invisible, incorporeal, and capable of moving in any direction, even up or down....

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This raises a few questions:

1. Is Glitterdust guaranteed to affect the enemy wizard? He would only take half damage from a damaging spell like Fireball, but Glitterdust doesn't inflict damage. Does the effect have a chance to miss, and if so, is it 20% or 50%?

2. Assuming that he is affected by Glitterdust, does it reduce the miss chance on physical attacks against him to 20%? Normally Glitterdust lets you see invisible creatures, but being ethereal is more than just being invisible. For example, an invisible creature hit by a Fireball would take full damage, whereas a wizard under the effects of Ethereal Jaunt would be unaffected, right?

Answer 1

Glitterdust will effect a blinking character normally because of its duration.

The rules for Blink stipulate that damaging area-effect spells inflict half damage. Glitterdust doesn't cause damage. The rules also state that individually-targeted spells have only a 50% chance of affecting a blinking character. Glitterdust is an area-effect spell. So RAW, Glitterdust is in a category of spells not technically covered by the Blink rules. So we look at what that 50% failure rate is meant to simulate. Since characters blink in and out, the 50% failure rate for spells (and attacks) is meant to simulate the chance that--at the instant of impact/spell effect--the character becomes ethereal and avoids the effect. But Glitterdust is not an instantaneous effect, its duration is 1 round/level of the caster (at least 18 seconds since it is a 2nd level spell). Therefore a Glitterdust cloud hangs around for longer than a sword stroke or magic missile and if the character is within the area, they will blink in at some point during its effect and be affected by the spell as normal:

A cloud of golden particles covers everyone and everything in the area, causing creatures to become blinded and visibly outlining invisible things for the duration of the spell. All within the area are covered by the dust, which cannot be removed and continues to sparkle until it fades. Each round at the end of their turn blinded creatures may attempt new saving throws to end the blindness effect. Any creature covered by the dust takes a -40 penalty on Stealth checks.

Glitterdust would not impact the 50% miss chance on hits rolled on a Blinking character.

Glitterdust does not render a character invisible, so invisibility does not come into the question here unless the Blinking character is also invisible. If the Blinking character was also invisible, then Glitterdust "visibly outlines" them. Whether visibly outlining an invisible character negates or reduces the penalty to hit them is an open question (see below), but a blinking, glitterdusted, invisible character would at least retain the 50% miss chance advantage of the Blink spell--this is because that 50% miss chance isn't based on any difficulty in perceiving the character, it is based on the fact that the character may become ethereal and be physically impossible to hit. Of course a Glitterdusted character does get the -2 AC blindness penalty if and for as long as the spell blinds them, which makes it easier to roll a hit in the first place.

A character under the effects of Ethereal Jaunt would not be affected by Fireball or Glitterdust.

The 50% chance of a spell impacting Blinking character simulates the fact that they randomly become ethereal and non-ethereal and would be unaffected if they happened to become ethereal at just the right moment. A character using Ethereal Jaunt becomes ethereal and does not randomly become non-ethereal. Unless a spell cast by a caster on the Material Plane causes a force or abjuration effect (neither Fireball or Glitterdust do) then it would not affect an ethereal character.

Does Glitterdust negate the defensive advantage of Invisibility?

All the rules for Glitterdust state is that an invisible character is "visibly outlined," becomes blinded (Will save may negate blindness only), and has a -40 penalty on Stealth checks. However, there is a similar spell, Faerie Fire, which also "outlines" those affected and only causes them a -20 Stealth penalty. So it would appear that, based on Stealth penalties, Glitterdust's effect is more visible than Faerie Fire's. Now under the Faerie Fire rules: "Outlined creatures do not benefit from the concealment normally provided by darkness (though a 2nd-level or higher magical darkness effect functions normally), blur, displacement, invisibility..." (emphasis added). If Faerie Fire negates an invisible character's 50% miss chance for total concealment without making them actually visible, then so should Glitterdust, at least in my opinion. I believe the fact that the Glitterdust description does not state that it negates invisibility concealment is an oversight and not RAI.