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Incorporeal creatures can only be harmed by other incorporeal creatures, by +1 or better 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
Incorporeal creatures move in any direction (including up or down) at will. They do not need to walk on the ground.
Incorporeal creatures can pass through solid objects at will, although they cannot see when their eyes are within solid matter.
Incorporeal creatures are inaudible unless they decide to make noise.
The physical attacks of incorporeal creatures ignore material armor, even magic armor, unless it is made of force or has the ghost touch ability.
Incorporeal creatures pass through and operate in water as easily as they do in air.
Incorporeal creatures cannot fall or suffer falling damage.
Corporeal creatures cannot trip or grapple incorporeal creatures.
Incorporeal creatures have no weight and do not set off traps that are triggered by weight.
Incorporeal creatures do not leave footprints, have no scent, and make no noise unless they manifest, and even then they only make noise intentionally.