"A thousand years from tomorrow," after the Neutron Wars, the world is divided into a barbaric collection of city states, surrounded by wastelands where only mutant cannibals and independent warriors, known as Range Guides, can live. The city state of Helix is planning war on another, Tritan. Hoping to prove their newest weapon's superiority, the "Death Machines" (laser equipped Dirt bikes), they create a new Death Sport.
The death penalty has been replaced by Death Sport, where criminals battle each other to the death for their freedom. Lord Zirpola (David McLean) is using the "Death Machines" against some Range Guides he managed to capture. One of the guides, Kaz Oshay (Carradine), forges a bond with the female guide Deneer (Jennings) and vows to escape with her and find her child who was taken by mutants before her capture.
After enduring torture and facing his mother's killer, Ankar Moor (Richard Lynch), Oshay and Deneer are forced into the Death Sport motocross field, which is mined with explosives. They easily defeat the other riders and escape into Helix city with two other prisoners, Doctor Karl (William Smithers) and his son Marcus (Will Walker). During the escape, though, the doctor is killed.Eventually they rescue Deneer's child from mutant cannibals, and battle the other Death Machine riders who followed them. Finally safe, Deneer delivers Marcus to Tritan, while Kaz Oshay faces his nemesis Ankar Moor in "honorable" combat, using Whistlers (plastic swords that sound like music). After a bloody battle Kaz decapitates Ankar, becoming the greatest guide alive. The film ends with him and Deneer riding their horses off into the sunset.