Unseen characters can develop organically even when their creators initially did not expect to keep them as unseen, especially in episodic works like television series.
This definition, according to Green, would rule out a character like Laurent (Lawrence), Tartuffe's unseen valet, whose sole function is merely to give the playwright an opportunity to introduce Tartuffe. Green suggests that an "invisible character" can be defined as one who, though not seen, "influences the action of the play".
In a study of 18th-century French comedy, F. The use of an unseen character "take advantage of one of the simplest but most powerful theatrical devices: the manner in which verbal references can make an offstage character extraordinarily real to an audience," exploiting the audience's tendency to create visual images of imaginary characters in their mind. Indeed, their absence makes them appear more powerful because they are only known by inference. Unseen characters are causal figures included in dramatic works to motivate the onstage characters to a certain course of action and advance the plot, but their presence is unnecessary. Eugene O'Neill was influenced by his European contemporaries and established the absent character as an aspect of character, narrative, and stagecraft in American theatre.
However, it was the early twentieth-century European playwrights Strindberg, Ibsen, and Chekhov who fully developed the dramatic potential of the unseen character. Unseen characters have been used since the beginning of theatre with the ancient Greek tragedians, such as Laius in Sophocles' Oedipus Rex and Jason's bride in Euripides' Medea, and continued into Elizabethan theatre with examples such as Rosaline in Shakespeare's Romeo and Juliet.