What is Incorporeal Touch?

[Gale]

I don't understand how Incorporeal Touch works. It seems most ghosts have it as an attack but I can't find an explanation anywhere as to what it does. It's mentioned in the Monster Manual that ghosts can't attack non-ethereal beings by traditional means; they can't hit a living human with a ethereal sword because it would go through him. I'm presuming Incorporeal Touch is a way of getting around this, I just can't find any confirmation on this. Is it simply an attack that hits ethereal and living creatures?

[sonofzeal]

It's two different qualifies. "Incorporeal" means subject to the advantages and limitations thereof. "Touch" means it targets Touch AC, rather than regular AC.

[Urpriest]

The Rules Compendium has a more detailed explanation of the sorts of attacks Incorporeal creatures can make.

While most Incorporeal creatures are not Ethereal, a Manifested Ghost is present on both the Material and Ethereal planes, which has specific effects detailed in its entry, including the ability to use its Incorporeal Touch on both Material and Ethereal opponents, adding Str to damage against Ethereal targets.

[Necroticplague]

The long and short of it: incorporeal touch attacks are normal touch attacks. However, you can also add armor and shield bonuses to your ac against it if the bonus is a force effect (like mage armor or shield spell).