Autobot, a faction of sentient robots from the planet Cybertron, are usually the main protagonists in the fictional universe of the Transformers, a collection of various toys, graphic novels, paperback books, cartoons and movies first introduced in 1984. In all but one Transformer story, the "Heroic Autobots" are opposed by the "Evil Decepticons"—the main antagonists in Transformers. Both Autobots and Decepticons are humanoid robots that can transform into machines, vehicles and other familiar mechanical objects. Autobots often turn into civilian vehicles but some are aircraft and military vehicles. While the Autobots have always found themselves outnumbered by the Decepticons, the Autobots have always had home-field advantage, having not only the human's military support, but also having more places on Earth to fall back on, while the Decepticons are entirely unwelcome on Earth.