Impromptu Sneak Attack (Ex)

Once per day, a rogue with this advanced talent can declare one melee or ranged attack she makes to be a sneak attack, with the normal range restrictions on ranged sneak attacks. The target of an impromptu sneak attack loses any Dexterity bonus to AC, but only against that attack. The power can be used against any target, but creatures not subject to critical hits take no extra damage. A rogue must either have the major magic rogue talent or the ability to cast spells before selecting this talent.