This recently came up in my Red Hand of Doom game. Evidently there is a bit of a discrepancy in how incorporeality is handled in the DMG vs. the MM. (I've bolded the relevant detail.)
From the DMG section on incorporeality:
Incorporeal creatures can be harmed only by other incorporeal creatures, by magic weapons, or by spells, spell-like effects, or supernatural effects. They are immune to all nonmagical attack forms. They are not burned by normal fires, affected by natural cold, or harmed by mundane acids.
Even when struck by magic or magic weapons, an incorporeal creature has a 50% chance to ignore any damage from a corporeal source-except for a force effect or damage dealt by a ghost touch weapon.
From the MM section on the incorporeal subtype:
An incorporeal creature has no physical body. It can be harmed only by other incorporeal creatures, magic weapons or creatures that strike as magic weapons, and spells, spell-like abilities, or supernatural abilities. It is immune to all nonmagical attack forms. Even when hit by spells or magic weapons, it has a 50% chance to ignore any damage from a corporeal source (except for positive energy, negative energy, force effects such as magic missile, or attacks made with ghost touch weapons). Although it is not a magical attack, holy water can affect incorporeal undead, but a hit with holy water has a 50% chance of not affecting an incorporeal creature.
The main thing to note is that the DMG makes no mention of positive or negative energy effects overcoming incorporeality, while the incorporeal subtype in the MM does. One interpretation is that such effects overcome the incorporeality of creatures with that subtype, but not creatures that gain it via some other method such as a spell or magic item. That is probably closest to rules as written...but it seems lame to me.
I've looked through the MM and DMG errata, and saw no reference to this. I also did not find reference to it in the FAQ. Anybody hear of a ruling on this? How do others play it in their games when, say, a cleric tries to cast a cure spell on a wraith? Do you roll the % miss chance for incorporeality or not?
