Zero is a proprietary game engine created by Pandemic Studios. It was used first in the game Battlezone II: Combat Commander and later used in several Star Wars games including the popular Battlefront series. Battlezone II: Combat Commander and Dark Reign 2 both feature an in-engine editor accessible via commands. The engine was revamped for Star Wars: The Clone Wars to accommodate consoles and third person gameplay. The engine was again retooled for Star Wars: Battlefront and the level editor was made a separate entity from the game engine. A set of modding tools including ZeroEdit, the new level creation tool, were released for use with Star Wars: Battlefront on December 23, 2004. An updated version of the tools were released on February 2, 2006 for Star Wars: Battlefront II. Pandemic used Zero as their primary engine for several of their games developed in their Los Angeles, California studio. A modified version of the Zero engine was also used in Pandemic's Mercenaries 2: World in Flames.