Two Lore Warden's and Critical Hits

[Drake Brimstone]

Lets say two level 20 Lore Warden's (Fighter Archetype) are fighting each other.

If Lore Warden 1 rolls a Natural 20 and uses their level 19 ability to auto confirm, can Lore Warden 2 force them to roll it anyway by apposing it with an Acrobatics Check (Level 11 ability Hair's Breadth) or does their need to be a confirmation roll to start with to use that ability?

I think it's the later, no roll to counter so you can't negate it that way, but am curious on others opinions.

On another note, lets say some character attacks a Lore Warden with Hair's Breadth and rolls two natural 20's, one to hit, one to confirm. Lets also say they have a +10 to their confirmation roll and the Lore Warden has a +20 to their Acrobatics skill checks. Can the Lore Warden roll an 11 or higher on the die for Acrobatics (31 total) to beat the total 30 confirmation roll and reduce the critical hit to a normal hit?

I read it as the later on this one as well because the roll is to beat the confirmation roll, not to "set" a target AC for the confirmation roll.

[FrodoOf9Fingers]

I think this falls under the debate of what happens to abilities that rely on confirmation rolls when you auto confirm. Another one you might look at is Tripping Strike with a level 20 fighter using his favored weapon.

[blahpers]

I'm not certain how one would adjudicate making an Acrobatics check higher than a nonexistent confirmation roll.

[Dave Justus]

I would treat an auto-confirm as being identical to having rolled a natural 20 on a confirmation dice. This is based on the idea that a natural 20 is also an auto-confirm (regardless of AC) for a threatened critical. To negate it, the DC would be calculated as if they had rolled a natural 20.

I don't have any really strong RAW support for this interpretation however.

[FrodoOf9Fingers]

Seems appropriate in power for a capstone ability... Makes tripping strike always work too.