- For other uses, see Psi.
Psi rating is a scientific measurement of a lifeform with the ability to use psionic abilities, usually referring to a sentient lifeform.
History and specifics[]
The psi rating used in and around the Federation in the 23rd century was a numeric scale that measured the capability to use telepathy, telekinesis and extrasensory perception. According to this rating, most Humans rated around 10, while Vulcans scored 30. The Iruhe of 4408B Trianguli had a psi rating of nearly 160, one of the highest ever recorded. (TOS - Rihannsu novel: The Romulan Way)