Metzen's first work for the company was with the game "Justice League Task Force", in which he provided artwork and character animation. Around the same time, Metzen also contributed to 1994's ' by working on artwork, illustrations and the game's documentation. Later video games by Blizzard Entertainment would frequently include Metzen's work in manual design, illustration and concept art. However, Metzen's role in developing later "Warcraft" games increased significantly with 1995's ', which gave him the opportunity to work on the game's fantasy-based fictional universe in addition to designing the game's various scenarios and missions.