Magic:Improved Invisibility

Illusion (Glamer)
Level: Brd 4, Sor/Wiz 4, Trickery 5
Innate Level: 4
Component(s): V, S
Casting Time: 1 action
Range: Personal or touch
Target: Single
Duration: 1 Minute/Level
Counter(s): --
Saving Throw: None
Spell Resistance: No
Metamagic: Extend, Quicken, Silent, Still
Energy Substitution: No

The target creature becomes invisible and impossible to detect using normal vision. After attacking or casting spells the target creature will become partially visible and detectable by enemies, but still retain a 50% concealment bonus.