Matt Morris was the lead level designer of Legacy of the Void. He also worked on the game's story. He is currently the lead designer for Co-op Missions. This includes mission design, commander design mechanics, and the UI that connects the players to the missions. Morris joined Blizzard Entertainment in 1998, beginning work in quality assurance. He worked on Diablo, StarCraft, StarCraft: Brood War, and Diablo II, before working on level design in Warcraft III. He was part of the original World of Warcraft team before he was transferred to work on StarCraft II as a lead level designer.