Although there has been some speculation that Much Ado about Nothing may be a heavily revised version of a play that Shakespeare wrote earlier in his career (a "lost" work that is often referred to as Love's Labour Won), Much Ado was probably written by Shakespeare in 1598 or shortly thereafter. This would make Much Ado one of Shakespeare's later comedies. Unlike his earliest comedic works, the humor of Much Ado about Nothing does not depend upon funny situations. While it shares some standard devices with those earlier plays (misperceptions, disguises, false reports), the comedy of Much Ado derives from the characters themselves and the manners of the highly-mannered society in which they live.
And while the main plot of Much Ado revolves around obstacles to the union of two young lovers (Claudio and Hero), the plays sub-plot, the "merry war" of the sexes between Beatrice and Benedick, is much more interesting and entertaining by comparison. Indeed, the play was staged for a long period of time under the title of Beatrice and Benedick. Especially when set alongside the conventional, even two-dimensional lovers of the main plot, Beatrice and Benedick display a carefully matched intelligence, humor, and humanity that is unmatched among the couples who people Shakespeare's comedies. Beatrice and Benedick aside, Much Ado has been the object of sharp criticism from several modern Shakespeare scholars, the gist of their complaint being that it lacks a unifying dramatic conception. More pointedly, while Much Ado is comic, it also has some disturbing elements. That being so, it is often classified as a "problem play," akin to The Merchant of Venice in raising the possibility of a tragic ending and in presenting us with "good" characters, like Claudio, who nonetheless act "badly."
Did this raise a question for you?