Twilight Knife.

[gagnrath]

Twilight knife in the spell allows/creates sneak attack.

It is also a force effect so it effects incorpreal fully.

However . An incorporeal creature is immune to critical hits and precision-based damage (such as sneak attack damage) unless the attacks are made using a weapon with the ghost touch special weapon quality.

So does twilight knife do sneak attack damage to incorpreal creatures?

[dragonhunterq]

Strictly speaking no, a force effect is not the same thing as ghost touch.

I haven't really checked if there's many situations where it arises, but if there is an incorporeal creature that doesn't have the incorporeal subtype -such as someone using blink - then they don't get that immunity and you can sneak attack away with your knife.

[Herr James Anderson]

on the other hand, force effects deal full damage to incorporeal creatures, unlike most kinds of magic damage, thus theoretically you could say yes. it's not a matter of rules (that do not mention this kind of situation) but a matter of lore. The force (not to mistake with Star Wars) exists in the Material Plane as much as in the Ethereal Plane. According to the rules, force effects deal full damage to ghosts, walls of force can block ghosts etc. so the force is as material as it is ethereal. you have to consult to your GM about this, but as a GM, i would allow it to do sneak damage

[gagnrath]

Are we doing a debate of General VS specific here as well, the Twilight knife does sneak attack... (Specific to the spell)
Vs, General (Incorporeal Subtype... Immune Unless Ghost Touch)

This is to do damage to a shadow demon that has taken up residence in a ruined castle with a floor under a non-dispellable deeper darkness. (castle was there before with the deeper darkness, ended up rolling the shadow demon on a random encounter chart and the DM decided that it made sense for the demon to take up residence there.).

We are a party that is now short our priest (captured with magic jar in the first encounter with the demon. A bit short on magic weapons, We've got a pair of +1 weapons, and a decent amount though not great amount of cash. We've got a diplomacy/con-artist rogue, a witch (my character), and a monstrous brawler that is able to do some damage though the DR of the shadow but not a lot. The cleric once we get her free is likely able to take out the demon (she was close with channeling initially and can align weapons) but getting her free is not completely certain. (prot from evil grants another save with that and fortune with her will save the odds are pretty good)

Current spells are

1. Beguiling Gift
Burning Hands
Command
Cure Light Wounds
Enlarge Person
Identify
Mage Armor
Mount
Ray of Enfeeblement

2. Alter Self
Burning Gaze
Blindness/Deafness
Cure Moderate Wounds
Delay Poison
Glitter Dust
Spectral Hand
(animate rope (patron)

3. Twilight Knife
Lightening Bolt,
Stinking Cloud
Remove Curse

I just leveled to 6th so can select 2 more spells from either the APG or Core but don't have much that will be helpful here that I can see. Suggestions would be helpful.