Savants

From publisher blurb:

Savant: one who exhibits exceptional skill or brilliance in some limited field

Some call them specialists but all call them dangerous. Savants presents the allure and power of previous editions’ "specialists" to your Shadowdark game. Bring clarity of focus to your magical domain of choice while at the same time risking capable casting of all other spells. Concise and clear as all SD rules should be, you’ll be launching War spells with a fierceness unrivaled or expertly befuddling foes with your Trickery spells at character creation!