Background:
This is just a frequently asked question that comes about because the same word (armour) is used for two different technical terms. The answer is clear, but noobs always, always, always ask this. Please make this answer fully and completely official.

Question:
Q: What does "damage that ignores armor" actually ignore?
A1: It only ignores the numerical value of the damaged figure's armor (item).
A2: It ignores the numerical values of the combined armor of that damaged figure. That includes the numerical values of the figures' Base Armor and equipped Armor Item as well as any other numerical bonuses applicable (such as the Ring of Protection or Parry). It does not ignore special abilities such as the wound prevention abilities of the Tunic and various Cloaks.
A3: It both ignores the numerical value of the damaged figure's combined armor (Vase Armour+ armour item bonus + special bonuses from skills and non-armor items) and the special abilities of any armor the damaged figure has equipped.
A4: It ignores all aspects of the damaged figure's equipped Armor Item (both numerical Armor bonus and special abilities). It does not ignore the figure's Base Armor or any Armor bonuses from non-armor item, skills or special abilities.

Comment:
If the answer isn't A2, I quit!

Corbon said:

LOL.

I agree it should be A2, of course. I could live with A3. If the fine folks at FFG seriously put forward A1 or A4, then I'd have to house rule it back for our games, though =P

I would suggest that the "background" list the two things the word "armor" is used for (a numerical stat that reduces wounds lost due to damage, and a category of item limited to 1 equipped at a time).

A1 and A4 might want to emphasize that monsters don't have armor items, and therefore would be affected exactly the same as with normal damage. Assuming that we need A1 included at all, which I'm not sure we do.

We might also want to say somewhere that A2 is alleged to be an official answer from one of the forum's former lives.

Several of those answers seem unnecessarily vague or hard to read. A1 seems to be missing several key words that would make it make sense to someone not already familiar with this debate, A2 and A3 seem to invent unnecessary terminology. I might word them something more like this:

A2. It ignores a figure's armor stat, including all bonuses from all sources. It does not ignore other effects of a hero's equipped armor item, such as wound-cancellation on a Cloak of Displacement or immunities from Dragon Scale Mail.

A4. It ignores all the effects printed on a hero's equipped armor item. The hero's armor stat is applied normally, though it will not receive a bonus from his equipped armor item against that damage. It has no effect on monsters, since they do not have items.

A3. It ignores a figure's armor stat, including all bonuses from all sources, and ALSO ignores all other effects of a hero's equipped armor item, such as wound-cancellation on a Cloak of Displacement or immunities from Dragon Scale Mail.

A1. It only ignores bonuses to a hero's armor stat, and only those granted by his equipped armor item. The hero's armor stat is applied normally, though it will not receive a bonus from his equipped armor item against that damage. It does not ignore other effects of a hero's equipped armor item, such as wound-cancellation on a Cloak of Displacement or immunities from Dragon Scale Mail. It has no effect on monsters, since they do not have items.

Corbon said:

In ancient times, the official answer from KW had been A3, actually. It was changed by himself to A2 a couple of months later.

if the above is true then it it quite clear that they make rules as they go. So there was a time that damage that ignores armor ignored also cloak of mists ability and the like?

Drglord said:

Or they just made a mistake.

Drglord said:

He gave the answer equivalent to A3 when I asked this very same question on the forums shortly after buying Descent. He responded directly to me in the forum. The very next time someone asked this question (which was about a week or two later IIRC) he gave the answer equivalent to A2 while responding to that person. Thereafter the answer has always been A2 whenever someone asked. I believe it was in the FAQ for a while, though I'm not sure that it still is.

At first I found this situation humorous, but looking back with the fullness of time, it seems to me that Kevin's response to me was off the cuff and it was later changed after they had had a little time to think about/play test it. This may well also be why the game designers don't respond directly to questions in the forum now. =P

As far as making up the rules as they go, yeah, that's sort of what FAQ and errata are. Corrections and clarifications for areas where the originally printed rules are incorrect or unclear. If the FAQ or errata answer proves too troublesome, it may well get changed again in the name of trying to make the game work smoothly.