Radiation was a byproduct of many natural and artificial substances. Deadly items that were of this nature were deemed radioactive. Radiation encompassed the entire electromagnetic spectrum, including gamma rays, ultraviolet, infrared, and microwave radiation. It was categorized into five phases, with Phase 5 being the deadliest. Doses of radiation could produce genetic mutations in creatures, resulting in mutants and other ghastly beings such as Coruscani ogres.