Using the power of their mind, psionicists can control and change their physical being, environment and the creatures within it. They do this by mentally molding their own bodies, minds and spirits into a unified source of energy, which they channel and release as pure, raw mental thought.
Mentalists are born with basic abilities and gain more control over their mind powers by practicing and acquiring new techniques. Once proficiency is attained, the power emanating from the psionicist can be extended to move and manipulate others. Mentalists spend so much time expanding their minds that they ignore their bodies -- thus they are frail and weak. The mental capactiies of the psionicist, however, easily rival, and sometimes exceed, that of most magic users.
Psionic abilities are found only in the evil Illithid race and, to a very small degree, in the Yuan-Ti peoples of Faerun. The Yuan-Ti, however, do not have the ability to refine their talents and therefore cannot expand beyond the limitations they are born with.