Rather than a specific genre, the term indicates a period (approx. from the late fifties to the early seventies) in which the Italian film industry was producing mainly brilliant comedies, with some common traits like satire of manners, farcical and grotesque overtones, a strong focus on "spicy" social issues of the period (like sexual matters, divorce, contraception, marriage of clergies, the economic rise of the country and its various consequences, the traditional religious influence of catholic Church) and a prevailing middle-class setting, often characterized by a substantial background of sadness and social criticism that would dilute the comic contents.
As he said in an interview with the director Mario Monicelli, the Italian comedy (Commedia all'italiana) is something very simple, which is closely tied to popular culture of Italy. It is a tangle of stories of poor and unfortunate in a highly unfortunate and negative, i.e. the period of poverty that followed in Europe and especially in Italy after the end of World War II. In any plot of the films of this genre, there is a group of thieves and bandits who would like to make ends meet by ramshacklely preparing a big hit. However each has its problems and its difficulties, attibutable to ignorance, incompetence, inadequate means, unrequited love and many other mishaps. The whole plot of the story revolves around these seemingly unnecessary misunderstandings, allowing the viewer to have a clear and precise vision of the deficiencies of the Italians of that period and of both the gloom and joy of the whole of Italy. The group of cheaters, apparently chieving their aim with deceit and cunning, at the end of the story almost always find themselves duped and crushed economically and psychologically worse off than before. Whoever comes out best the story is always the most powerful, either in the political arena or in some other social context. What makes the viewer laugh are the jokes about the repeated blunders of the actors that would make them famous during the preparation of their shots. The element of sadness is very much present in all the stories on the theme of Italian comedy, not just the mockery of the poor people who seek to improve their situation, but also to the bitter end show a bitter smile and a dim hope of the protagonists into the future. Just think of the situation or the tragic end of the film Il sorpasso (Dino Risi) or the melancholy end of the film I soliti ignoti in which thieves have fail in their coup, losing everything they had. Another important feature of this type of comedy is the feeling, although the social condition of the people who populate the stories is extremely low, the protagonists have shown great will to live, to love, to dream, to become almost a taste of the film sentimental. What breaks this feeling is a typical Italian clumsiness or a fall, which immediately pulls the viewer a big laugh. The protagonist is at once sentimentally duped. In the sixties and seventies such plots merged with the satire. Even in these stories, such as in Signore e signori buonanotte (1976), as it denotes skill in manifesting Italian taste satirical scenes is exaggerated and extremely scratchy. The characters are targeted by powerful people or satire inept people, extremely rude, bad, almost animalistic, almost personalities related to the masks of the Commedia dell'arte. The Italian comedy ceased to exist in the eighties, by which time the principal actors had become old, replaced by a comic genre focused more on the vulgar and abusive side of the characters, which followed very American models. With the Americanized transformation of this comic genre in Italy, the kind of Commedia all'italiana finally died. The last film that famous still strongly reflects the characters of the Italian comedy is Il marchese del Grillo, directed by Mario Monicelli (1981). Alberto Sordi plays the role of a spoiled rich Marquis of Rome who is bored by the day. For this he designs jokes on the poor and the helpless for no particular end, as if they were toys from the living room. His joker cynicism is not stopped even by the power of Pope Pius VII. This film still strongly reflects the character of the average prankster kid of the sixties, who only caring about himself and what he has, not caring of others and to those most in need. Cynicism is the main theme of this film, based on a true story.