Shadow Cast

(Tome of Magic, page 137, DnD 3.5)

[General]

Your shadow shimmers as you cast a spell and you seem to cast your mysteries from elsewhere.

Prerequisite

Concentration 5 ranks, shadowcaster level 1st

Benefit

Designate a square adjacent to you. If no one threatens that square, you do not provoke an attack of opportunity when you cast a spell or use a spell-like ability