The Decepticons owe their warlike ways to their faction's origin as military hardware robots, created by the five-faced aliens the Quintessons while the Autobots were designed as consumer goods. Their bodies were forged by the Plasma Energy Chamber and given intelligence by the mega-computer Vector Sigma in order for the work to be carried out. Eventually they developed sentience and rebelled against their creators. However A-3 the resistance leader was displaced from time by Quintessons from the future in order to stop the insurgency. The resistance had help from future Autobots (whose transformation technology frightened them) and A-3 returned to turn the tide by activating his coda-remote which deactivated the Quintessons' Dark Guardian Robots. With the Quintessons cast off and forgotten Cybertron was at peace. The consumer goods and military hardware bots renamed themselves as Autobots and Decepticons.
However the Decepticons wanted war. No match for the superior firepower and battle prowess of the Decepticons the Autobots developed transformation technology (possibly with the help of the Dark Guardians) to win the war bringing about the Golden Age of Cybertron. Eventually the Decepticons also developed transformation and began the third Cybertronian War. They would have succeeded in completing their conquest had not more time-displaced Autobots blown up an energy warehouse and brought its workers to A-3 now renamed Alpha Trion as the new defenders of Cybertron. For five million years the Cybertronians warred over the remaining energy that was left. With this crisis the Autobots headed by Optimus Prime made an expedition to find new energy sources. But the Decepticons intercepted them causing the Autobot ship Ark to crash-land on Earth.
Four million years later in 1984 the volcano that the Ark was wedged in erupted jarring the Ark's main computer Teletraan I back online. Through use of Spy Satellites Teletraan created new alternate forms for the Transformers out of earth vehicles (Like F-15 Eagles for Starscream and a Semi-trailer truck for Optimus Prime). The Decepticons were revived first and then the Autobots due to Starscream's carelessness. The Autobots made an alliance with the local humans thus beginning the Great War. After waging the war for 21 years the Autobots created Autobot City as their main base of operations while the Decepticons got complete control of Cybertron. In 2005 the Decepticons launched an attack on the city resulting in the death of Optimus Prime. Optimus managed to pass the Matrix of Leadership to Ultra Magnus before his passing. The city then received messages from the bases on Cybertron's moons being devoured by the transformer demi-god Unicron. After another Decepticon attack the Autobots were scattered to two planets, Junk and Quintessa. Forming new allies on those planets the Autobots headed for Cybertron. A young Autobot named Hot Rod used the recovered Matrix of Leadership from Galvatron (formerly Megatron) to destroy Unicron and became Rodimus Prime. With the Decepticons in disarray the Autobots reclaimed Cybertron bringing about a new age of peace and prosperity.
In 2006 the Great War still raged. But both sides rediscovered the existence of the Quintessons. After numerous battles the Hate Plague was unleashed. Rodimus ordered the uninfected Autobots to search for a Quintesson to revive Optimus Prime. An uninfected Quintesson was found and forced to restore Optimus Prime to life. Optimus would then recover the Matrix by defeating an infected Rodimus Prime and cure the galaxy of the plague. After one year of peace Galvatron gained access to the Plasma Energy Chamber. He planned to move Cybertron to Earth and use the Chamber's energies to overload the sun. However all this was planned by Vector Sigma who wanted to restore Cybertron's Golden Age. Thanks to Spike Witwicky and the allied-Nebulons, Cybertron regained its golden hue. Optimus knew that there will always be Decepticons and the Autobots will always stop them. On earth the Autobots always had the 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 were entirely unwelcome on Earth for a while they have control of Cybertron.
The word Autobot according to Ratchet is an abbreviation of the phrase Autonomous robotic organisms. The Prime title is a direct linguistic descendant of Primus. It identifies the one Autobot Commander that is entrusted with the Creation Matrix also known as the Autobot Matrix of Leadership. The Matrix is said to choose its own holder and when it is taken by a new leader (at the old leader's death) it transforms him into a larger, more powerful, wiser Autobot commander. Holders of the Matrix become one with the Matrix such that when the holder dies his Spark — the Transformer life-force — is absorbed into the Matrix. Decepticons assume leadership by assassinating whoever is currently in charge.
Species Name: Cybertronian, Autobot, Decepticon
Type: Humanoid Transformable Robot
Physical Traits: Able to transform into at least 2 different configurations one of which is humanoid and the other some form of vehicle. Autobots have blue eyes and often turn into civilian vehicles but some are aircraft, military vehicles, communication devices, weapons, and cyborg animals. Decepticons have red eyes and are usually known for turning into aircraft, military vehicles, construction vehicles and even smaller-than-human-sized objects.
Height: Varies greatly
Weight: Varies greatly
Mobility: Legs and one other type depending on vehicle mode
Sensory Organs: Visual
Reproduction: The spark of life
INT: 3D6, WIS: 3D6, STR: 3D6, DEX: 3D6, CON: 3D6, CHA: 3D6, MR: 3D6, HPs: CON +D20. The stats listed are baseline only as attributes vary greatly.
Orbit/Climate: 1 AU. Very stable, circular orbit, very stable surface temperature.
Atmosphere: Standard Oxygen/Nitrogen with significant ozone component in the stratosphere.
Feeding Habits: Energy but Energon is favoured
Lifespan: Unmeasured but at least 9 million years
Culture: The Autobots are benevolent, more tolerant than standard but still with some violence. The Decepticons are a malevolent, truly malicious race with no redeeming qualities at all.
Government: Has varied between Military Dictatorship by the Decepticons to Benevolent Monarch by the Autobots.
Population: Unknown as the Cybertronians have spread to many planets but considered in the billions.
Number of Stars: 1, location unknown
Star Type: M
Planetoid Belts: 3
Inner Planets: 6
Middle Planets: 1
Outer Planets: 9