He mainly wrote for theatre, but his short stories and novels too have a similarly important content. He in fact also wrote some delicious novels in which he described his thoughts, often following Sicilian legends, or Italian little facts. Pirandello composed over 350 short stories, generally on realistic themes of Italian and Sicilian life. His poetry is rather less considered.
His wife Antonietta soon revealed suffering heavy mental diseases, and this gave Pirandello a deep acknowledgement of mental mechanisms, which he often referred to in his works (notably in Enrico IV (Henry IV)). In Il berretto a sonagli (Cap and Bells), he described in detail how to "become mad": to tell everyone the truth, the sole and cruel truth, regardless of manners or respect and in spite of social habits, soon will produce isolation and a reputation of mad.
Pirandello's best-known work is probably Sei personaggi in cerca d'autore (Six Characters in Search of an Author). Equally notable, if not as often performed, are the plays Così è (se vi pare) (Right You Are (If You Think You Are)) and Ciascuno a suo modo (Each in His Own Way). Another play, Come tu mi vuoi (As You Desire Me), was adapted for a 1932 Hollywood film starring Greta Garbo.
In later years he became a close friend, and perhaps the lover, of Italy's most famous actress, Marta Abba. Ms. Abba translated several of Pirandello's plays into English, including La nuova colonia (The New Colony), and Pirandello's unfinished I giganti della montagna (The Mountain Giants). (Ms. Abba also translated a synopsis of the conclusion of The Mountain Giants, as told by Pirandello on his deathbed to his son.)
Pirandello's work was constantly devoted to the investigation of truth and the determination of a distinguished relationship between rational truth (reality) and socially accepted "truth" (manners?), in comparison with social mentality and individual personality, often bordering the sense of absurd, always glad to define a paradox.
In this sense, Pirandello is a cruel searcher of all those little habits in the small world of small society, and his essay about humour (Saggio sull'umorismo) might be an example of how in depth he could enter human mechanisms.
His supposed relationship with Fascism, to which he had expressed sort of enthusiasm, is now considered nothing more than a way he found to obtain an institutional assistance and sponsorship in creating his "Teatro d'Arte di Roma", having besides already personally experienced that bad enemies could cause him serious troubles (he had to graduate in Bonn because of his dispute with Roman university's director). Such a "civil manner" would be completely compliant with some of his best known plays. Criticism of fascism's "might makes right" philosophy is prominent in The New Colony.