Niche D20A creature who has become incorporeal has no physical body and as such is immune to all non-magical attacks. Magic weapons, spells, or supernatural effects deal half damage to an incorporeal creature. Other incorporeal creatures and effects deal full damage to an incorporeal creature.
An incorporeal creature cannot directly attack corporeal creatures using weapons or natural weapons, but may still affect them with touch attacks to deliver effects. Unlike attacks against incorporeal creatures, a incorporeal creature’s magic and effects from touch attacks deal full damage.
Unless otherwise specified an incorporeal creature cannot interact, and automatically passes through all corporeal objects.