Illusion immunity vs. Phantom Bolt/Illusory Ambush

[mwiedmann]

Duergar are immune to illusion, so how does that affect something like Phanton Bolt or Illusory Ambush that both have the "Illusion" keyword but deal "Psychic" damage? "Psychic is a keyword of the spells as well.

There appears to be 2 parts to each spell:
1. Psychic damage
2. Another effect like -2 penalty to attack roll or slide 1 square.

One way to rule this would be that the Duergar would but hurt by the psychic damage but would be immune to the additional effect as that would be the illusion part of the spell.

I'm not sure.

You could also rule that since they are illusion based spells the Duergar is immune to the entire thing.

What do you think?

 

[FireLance]

One way to rule this would be that the Duergar would but hurt by the psychic damage but would be immune to the additional effect as that would be the illusion part of the spell.

This is correct. As stated in the Compendium (and, I believe, in MM2):

Immune
A creature that is immune to a damage type (such as cold or fire), a condition (such as dazed or petrified), or another specific effect (such as disease or forced movement) is not affected by it. A creature that is immune to charm, fear, illusion, poison, or sleep is not affected by the nondamaging effects of a power that has that keyword. A creature that is immune to gaze is not affected by powers that have that keyword.​

Since a duergar is not immune to psychic damage, it will take damage from the power. However, it is not affected by the nondamaging effects of the power since it is immune to illusion.