Masteries are unique tech routes in Warlock that increase the effectiveness of the player's every ability. There are four available masteries: Duration, range, life steal and jack of all trades.
Mastering duration increases the duration of every buff and curse cast by the player, every buff received by the player and every channeled spell cast by the player.
Mastering range increases the range of all spells cast by the player.
Mastering life steal grants an increasing life steal for all damage dealt by the player.
Jack of all trades
But master of none: Upgrades all three masteries at a discounted price.