From the FAQ entry for the Chagrian Merc:
Quote:
Q: If a character gets a critical hit against a Droid enemy, can he add the +20 Damage from the Chagrian Mercenary Commander's commander effect? It seems that the bonus wouldn't apply because Droids are immune to critical hits.
A: Although Droids are immune to critical hits, this means only that they take the base damage instead of double damage (before applying modifiers). The attack is still considered to be a critical hit, and therefore it gets the bonus damage from the commander effect.
FAQ entry for Resilient:
Quote:
Resilient
Q: Is this immunity the same as for droids where it just prevents doubling of damage, or does it completely nullify the critical hit?
A: It nullifies the critical hit, but does not nullify the number rolled on the die. So damage would not be doubled, and something like the Chagrian Mercenary Commander's commander effect would not trigger, but Disintegration would still occur if a 20 was rolled.
So Droids still take everything other than the double damage, but Durge would just take a regular hit.
Also, here's the glossary entry for Flurry:
Quote:
When this character scores a critical hit (or makes an attack roll of natural 20, if the target is unaffected by critical hits), it may make one immediate extra attack, in addition to the other effects of a critical hit. It may make an extra attack each time it scores a critical hit, even as the result of this extra attack. The extra attack doesn't have to be against the same target if another legal target is available.
And for Vicious Attack:
Quote:
This character deals triple damage on a critical hit instead of double.
So Droids and Durge would still get hit by Flurry, but Vicious still wouldn't do anything, since the attack isn't considered a critical hit.