Monks can choose between Psionics and Acrobatics as well, and have the ability to specialize in Psychometabolism, a form of Psionics that affects the physical body. Several of the games published by Palladium Books, most notably "Beyond the Supernatural", feature psychic characters. The psychic powers in this universe are powered by Inner Strength Points (or ISP). "Beyond the Supernatural" (both 1st and 2nd editions) focuses almost exclusively on various forms of psychics, each with differing abilities. The games "Heroes Unlimited", "Palladium Fantasy Role-Playing Game" and "Rifts" also make extensive use of these rules. The basic psionics system does not vary much between each product. In some games (e.g. "Paranoia" and "Gamma World"), widespread, radiation-induced genetic mutation is the sole trigger responsible for psionic powers in player characters. The roleplaying game "Space Opera" treated psionics as an advanced science with many fields of studies, three levels of functioning (Psionically dead, Psionically open, Psionically Awakened) and vast number of skills. Characters that were open and been Psionically attacked or had contact with a raw PK Crystal could awaken, and characters with very high Psionic scores might be "contacted" and trained. Many role-playing games based on popular science fiction settings have at least telepathic powers available to players. Examples include the Psi Corps and other telepathic characters from "Babylon 5", Vulcans from "Star Trek", and the Jedi from "Star Wars", all of whom have demonstrated various degrees of psionic abilities ranging from telepathy to telekinesis to mental domination. "Traveller" includes the mastery of psionics as a career option in the character creation stage. The odds of naturally developing psionic powers are unlikely (the player must roll a seven on the Events table, followed by a twelve, followed by a one), if a player achieves this, they have access to a number of powers that they may develop during the character creation phase. In the Torg roleplaying game, psionics are only available at character creation to characters from the cosms of Core Earth (modern-day Earth) or the Star Sphere (the space opera cosm). Characters from other cosms 'can' learn psionic skills and powers during play, though when such characters use (or even possess) them it counts as a Contradiction. In White Wolf Publishing's World of Darkness, sometimes work magic through a paradigm of psionic power.