This is a specific question:
The Ghost Touch weapon property states that:
…Essentially, a ghost touch weapon counts as either corporeal or incorporeal at any given time, whichever is more beneficial to the wielder.
The most beneficial situation I can think of is that the weapon counts as incorporeal and ignores Armor and Shield bonuses, unless they're from force effects, or have the ghost touch property themselves. The weapon then counts as corporeal when striking, thus avoiding miss chances. Is this correct?
Indeed, I envision ghost touch arrows, bolts and bullets striking through total cover as if it weren't there (though concealment could still apply).
My question again is: Is my above interpretation that ghost touch weapons may ignore material cover, armor, and shield bonuses, yet not have an incorporeal miss chance, correct?
(I realize that this appears to be a repeat question, but neither the question nor the answer addressed this to my satisfaction.)
I forgot the second component of the question: How does this interact with the attacks of incorporeal creatures?
An incorporeal creature's attacks pass through (ignore) natural armor, armor, and shields, although deflection bonuses and force effects (such as mage armor) work normally against it. Nonmagical attacks made by an incorporeal creature with a melee weapon have no effect on corporeal targets, and any melee attack an incorporeal creature makes with a magic weapon against a corporeal target has a 50% miss chance, except for attacks it makes with a ghost touch weapon, [which] are made normally (no miss chance).
(I edited one word, 'while' to 'which' in the above quote, since it made no sense otherwise, and though I'm picking apart rules here, I'm not looking for 'silly-RAW' shenanigans)
So, it appears to me that an incorporeal creature's attacks with a ghost touch weapon continue to be incorporeal touch attacks, but with no miss chance. Am I correct there, or would they become normal material attacks, thus being affected by corporeal armor and shields?
Best Answer
The weapon special ability ghost touch doesn't allow the wielder to make incorporeal touch attacks
That last sentence isn't the extent of the description. In its entirety, the weapon special ability ghost touch says
When the text says, "Essentially, a ghost touch weapon counts as either corporeal or incorporeal at any given time, whichever is more beneficial to the wielder," the text is clarifying, providing the reader with a summary of the weapon's fundamental functions that have already been described. It means the weapon strikes foes despite their corporeal states and the wielder can continue to use the weapon despite the wielder's corporeal state. Nothing more.
As you've noted, taking that last sentence out of context makes the weapon special ability ghost touch way more powerful than it should be for its +1 bonus.
The weapon by that sentence isn't given additional properties beyond what's already been described.
The MM and DMG agree that an incorporeal creature's physical attacks (whether with a ghost touch weapon or not) ignore non-ghost touch or non-force material armor
In addition to the Monster Manual's description of the subtype incorporeal (310-1), the Dungeon Master's Guide on Incorporeality says that
So, while it's a little weird that a ghost (or an unbodied) can pick up from the floor a +1 ghost touch longsword and, bypassing the dude's full plate, stab the dude to death with that sword, that appears to be how it works. But were that sword not to have the weapon special ability ghost touch, the ghost would just look at the sword on the floor with despair. Okay, even more despair ('cause it's a ghost).