P scale (Babylon 5)

The P Scale or Psi Scale is a method of measuring telepathic power used in the fictional Babylon 5 universe by the Psi Corps, which controls and utilizes human telepaths, and subsequently throughout the Earth Alliance. The scale covers a wide range of different capabilities and ranges from P0 to P12. Lower ratings are more common than higher ones.

P0s and P1s are usually latent telepaths, with next to no abilities. What they do have tends towards the passive, such as being able to better receive telepathic communications and block some of them, or tell when they are being scanned. They have little chance of intercepting the thoughts of mundanes (non-telepaths). Stronger ones will pick up increasing amounts of nearby mundane thoughts without effort (or, indeed, choice) and have to semi-consciously block them out.

P4s and P5 are the most common commercial telepath levels, where a teep (telepath) is potent enough to be a valuable asset in negotiations. At P5, teeps can detect surface thoughts at close range without difficulty, and have limited other skills.

Very strong teeps rated P12 can become Psi Cops, the law enforcement part of the telepath community. Such telepaths are able to read the minds of others quite easily at long ranges, have sufficient strength to break through blocks weaker teeps may build around their own minds, and can manipulate the memories of others.

The scale does not measure telekinetic abilities, but as one out of 10,000 telepaths have TK (teeks) and one out of two telekinetics is sane, this is not a significant issue.

Given time P12s can do extensive reprogramming of a person, which was done illegally in the years leading to the Telepath War.

Though the scale only goes up to P12, which apparently is the strongest 'naturally occurring' level, this hasn't stopped everyone. Lyta Alexander was modified so that she was much stronger than even a P12. The Psi Corps did attempt to modify telepaths to make them stronger, and also manufactured the drug Dust to attempt to turn mundanes into teeps, with little success. According to the novel Dark Genesis: The Birth of the Psi-Corps by Gregory Keyes, the first director of the Psi Corps, Kevin Vacit, was considered by many to be a P13 partially due to a fragment of a Vorlon within him. Jason Ironheart, a subject of experiments to produce a stable telekinetic, eventually ended up off the scale entirely.