The It Factor and Why Nobody Agrees on It
Launch library · evergreen read

Casting directors sometimes describe a candidate as simply having it, a shorthand for a quality nobody can quite pin down yet everyone in the room seems to recognise at roughly the same moment during an audition, regardless of how differently each person might otherwise describe it afterward to a colleague.
Attempts to define this quality analytically tend to fail, since it resists the kind of checklist that other skills, diction, movement, timing, can reasonably be measured against with some consistency across candidates auditioning for the very same role. It seems to live instead in something closer to instinct, both the performer's and the observer's, arriving all at once in the room.
Because it cannot be reliably taught or manufactured, the it factor remains one of the more honest admissions an industry built on confident expertise still makes, that some part of what creates a star is simply recognised rather than explained by anyone directly involved in the process of casting.