Editing Savage Rifts - Phase World Adventures!:John Chrichton (section)

===Racial Overview (Mutant Superhuman)===
Mutant Superhumans are a genetic offshoot of humanity that possess superhuman powers of a non-psionic nature. In the Rifts setting they are indigenous to Earth and its space colonies. In the Three Galaxies the only place they are found is on the planet Seroon in the isolated system of the Charizolon System in the Corkscrew Galaxy (as seen in Rifts Dimension Book 4: Skraypers). Random examples from other dimensions such as Heroes Unlimited Earth could also be around.  Mutant Superhumans are capable of interbreeding with baseline humans, with the results of such unions always mutants.  Curiously, the offspring of a Mutant and a psychic human has an equal chance of reflecting either parent's heritage.

Innate Power: Arcane Background (Gifted) - Detect/Conceal Arcana (Limitations: Aspect (Conceal), Range Reduced to Self, Does Not Work Against Arcane Background (Gifted) Powers and Weird Science or Techno-Wizard Devices Deliberately Intended to Detect Arcane Background (Gifted) Powers, No Conscious Control - Automatically Activated by Detect Arcana Attempts of a Magical, Miraculous or Psionic Nature When Not Already Active, Must Always Short.)
(Modifiers: Does Not Inhibit Recharging While Active (+2), Failures to Activate Not Critical (+1), Strong (+1), Strong (+1)*)
*Listed twice deliberately for a cumulative -4 penalty to see through concealment.

The above represents mutant superpowers being very difficult to directly detect with spells or psionic abilities.  That's because they operaate on what could be described as a different "wavelength" than such powers, paranormal as opposed to supernatural.  Innate abilities specifically attuned and arcane devices that are deliberately calibrated to detect superhuman powers do not have to contend with such difficulties.  The occasions when Conceal Arcana fails represents a momentary fluctuation in a mutant's powers that generate a disturbance in the supernatural energies magicians and psychics can perceive, enabling such individuals detect superhuman powers indirectly from the "ripples" they create.