Esper

An esper (能力者) is an individual who uses scientifically based supernatural powers and emits AIM. It usually refers to those enrolled in the Academy City Power Curriculum Program, who gained their powers artificially, but can also refer to natural espers, also known as Gemstones. The term is also used to refer to magicians by those unaware of the magical nature of their abilities, and therefore define them as esper-related.

Terminology
The original Japanese light novels used the term "Ability User", but before the licensing of Toaru Kagaku no Railgun, the majority of the English-speaking fandom substituted it with "esper". Because its use has become widespread, this wiki uses the term "esper".

A queer event related to this is Seven Seas' English translation of the first volume of A Certain Scientific Railgun, which opted to use "psychic", a term that has been used before by the fandom until "esper" became the standard. Because of this, the English fans that were accustomed to the use of "esper" lobbied for "psychic" to be changed, and Seven Seas acquiesced, even referencing the incident later.

The term "esper" does not automatically imply ESP, one of the two classifications of powers in Academy City, as it could also refer to an ability user that does not have extrasensory perception but instead influences objects in their surroundings, referred to as Psychokinesis. Abilities such as Pyrokinesis are considered esper powers despite the user not having extrasensory perception.

Principles
Academy City's espers have existed for over half a century in the world of Toaru, with the first modern esper being a girl nicknamed "the Beginning Child", who was trained by Academy City based on Meiji-era psychic 's data. The system used for the Beginning Child would become the foundation for the Power Curriculum Program to create espers.

Espers are described by Index as individuals with "talent"; this likely refers to Gemstone and each cannot use magic without injuring themselves. An esper is created after passing through the Power Curriculum Program, thanks to which the esper now possesses a Personal Reality, their capacity to substitute reality with their own which is the basis of their abilities. In contrast to Magic's Idol Theory, their interference with and subsequent distortion of reality to create effects is an isolated phenomenon based on, their observations of the world based upon their Personal Reality affecting things on a micro quantum level to cause phenomena on a macro level. This is in stark contrast with holism, where a large interference with the laws of the whole world is used to make effects on a smaller scale. Aside from the mental performance of calculations, no elaborative and preparatory rituals are required by an esper to produce effects related to their abilities, unlike in Magic.

Espers can only access one specific power; Misaka Mikoto, for example, can only control electromagnetic phenomena. Despite this, however, researchers have attempted to create espers with multiple powers, such as Dual-Skill and Multi-Skill espers. Moreover, esper abilities are compartmentalised into two categories: Active and Passive. Active abilities require conscious effort to use, while passive abilities require subconscious effort. Abilities can be classed as both active and passive, such as Accelerator's ability.

Another aspect of espers is that every one of them, even Level 0s, radiates an AIM Diffusion Field, a natural energy field akin to body heat and weak enough that it is detectable only by machines. Different powers means a different AIM Diffusion Field: a Pyrokinetic for example will emit AIM that will heat up their environment, a Telekinetic will emit pressure, and an Electromaster will emit a weak magnetic field.



While the brain is an important component to esper power, it is not the only factor. The entire physical human body controls the power, and it is shown that, as long as something is considered a part of the body by the esper, esper abilities can be used with it, no matter if that part is attached or detached, artificial or natural. Kuroyoru Umidori can use Bomber Lance through her detached cyborg arms, which she considers parts of her body; Kakine Teitoku can control his Dark Matter even if it's not directly touching his body by no longer distinguishing between his actual body and the parts fabricated from his power;  and Rensa operates by changing her biological structure to that of other espers so she can use their abilities.

It is impossible to become an esper if one is an adult, to the point that the existence of adult espers is seen as improbable. Besides Therestina Kihara Lifeline, so far no adult esper have been shown to exist, aside from those who used various means to artificially get esper powers, like Kiyama Harumi with Level Upper, Kihara Gensei with Exterior, and Kihara Byouri with her Equ.DarkMatter implants.

Power Curriculum Program
A person enrolled in this program is called an esper and, through a series of drugs usages and experiments, will be cut off from regular reality and enabled the capacity to substitute it with their own. Espers are ranked according to their System Scan results; it is stated that Level 0 espers barely have enough influence to pass the curriculum's grading exams.

Any individual can use the curriculum to acquire powers, such as Misaka Mikoto, who started out as a Level 1 and worked hard during her training to become the 3rd ranked Level 5 esper in Academy City. There are exceptions of course, as with the case of Level 0s. Furthermore, with the Parameter List, it is apparent that esper potential is limited by various factors. This has resulted in researchers determining that it would be wise to focus on developing an esper whose ability is worth more to the city and whose training is predicted to be more resource efficient than that of another person's.

Information regarding the students enrolled in the curriculum, such as their abilities, their level and a brief description of them, is available in the Data Banks of Academy City. Furthermore, certain espers, such as Kamijou Touma, have security protocols in place to ensure that the truth of their abilities is classified.

According to Uiharu Kazari, the name of an esper ability, such as Electromaster or Telekinesis, is decided by the school that its owner is enrolled in. Only under specific conditions can the name of an esper ability be decided by its owner, such as the Railgun. It is unknown, however, as to what exact conditions an esper must meet to officially name their own esper ability, though its uniqueness may be a factor.

Currently, only Academy City can create espers, although others have tried, such as during the Stargate Project.

Gemstones and speculation
A Gemstone esper is an individual who can emit AIM without requiring participation in any power development program. Gemstones are the beings that Index likely referred to as having "talent"; the envy of their abilities from their peers is what led to the creation of magic. There are currently 50 confirmed Gemstones in the world.

In extension to this, it has been speculated that there may be people who have not realized that they have powers, or that their certain propensities or idiosyncrasies, as subtle as good looks or good penmanship, may actually have this power.

Many Academy City students are aware of Gemstone rumors, but treat them as urban legends. This is due to many feeling that it is unfair for esper powers to be gained without having gone through the Power Curriculum Program to attain them. Currently, Sogiita Gunha, who is the strongest Gemstone, and Himegami Aisa are the only two known Gemstone's in Academy City. Kamijou Touma, as mentioned by Kumokawa Seria, does not classify as a Gemstone esper as due to his powers being unrelated to AIM; it is believed that Imagine Breaker is beyond the current understanding of Academy City researchers.