Dino-Riders was introduced primarily as a promotion to launch a new Tyco toy line. The series told the story of the Valorians, a peaceful race of telepathic humans whose home planet was conquered by the Rulon Empire. 400 survivors escaped on a space ship and time traveled to prehistoric Earth using the experimental Space-Time Energy Projector (also known as the S.T.E.P). But Emperor Krulos and his lead commanders accidentally followed them into the past when a tractor beam locked onto the Valorians' ship during the time jump. Stranded in the past, the two groups recruited the planet's dinosaur population into their struggle. The Valorians used their telepathy for taming dinosaurs to ride and for domestic use. The Rulons captured dinosaurs with 'brain boxes'. These were large metal helmets which fit onto dinosaur's heads and control their brains. Both Valorians and Rulons would often fit dinosaurs with huge arrays of laser and weapon platforms, upon which people could ride, and attack one another. Battles were mostly motivated by the Rulon's desire to steal the S.T.E.P. from the Valorians, and almost always inconclusive, seldom accomplishing more for either side than restoring the status quo from the beginning of the episode.