Slave Mastery
From Starsonata Wiki
Slaves get +2% to most stats. It costs five skill points and goes to level 20 at von Mises (space station) in Free Market. You must have at least the same level of Remote Control skill as the level of slave mastery you are attempting to train. Slave mastery is prerequisite for: Seer, Drone Mastery, Radiation Expert, and Merchant Fleet Mastery.