Throughout the history of theatre, two opposing extremes have repeatedly emerged. On the one hand is abstract formalism, which overlooks the fact that the dramatic text constitutes the foundation of theatrical performance. On the other hand, is a text-cantered approach that seeks all meaning exclusively within the script, reducing the play to a vehicle for slogans and ideas while neglecting the aesthetic dimensions that connect it to the contemporary context of its production. Caught between these two poles, genre plays have often been marginalized by both camps. Such works are frequently dismissed as conservative: by the former for their adherence to conventional forms, and by the latter for their perceived conservatism in thought and content. Yet these judgments may be premature. A closer and more rigorous examination of genre plays reveals their potential to make significant contributions to both theatrical form and thematic substance. Rather than viewing them as merely conventional, it is necessary to investigate the distinctive aesthetic and intellectual possibilities they offer to the art of theatre. Meanwhile, Anthony Shaffer is recognized as one of the most significant playwrights and screenwriters working within the genre tradition. The case study of this research is his play Whodunnit and the term ‘whodunit,’ a modified form of the question ‘Who done it?’ which refers to detective novels, plays, and films in which the identity of an unknown murderer is revealed only at the final stage of the narrative. Whodunnit is among Shaffer’s most complex and, at the same time, most captivating works. Nevertheless, there remains a risk that the play may be interpreted in two contrasting ways. On the one hand, directors who seek to assert their own authorship may regard it as a text that restricts their creative freedom in performance. On the other hand, directors who rely exclusively on the script may criticize it for its excessive formal complexity, viewing it as a work preoccupied with technique at the expense of substantive meaning and intellectual depth. But does this play—or others classified as generic dramas—lack formal (theatrical) or thematic accomplishments? This study adopts a descriptive-analytical method and a qualitative approach to explore the theatrical merits of the play, which belongs to the metatheatre category. It investigates both the textual and performative dimensions of the work, drawing on Lionel Abel’s theoretical framework to support its analysis. The plot of Whodunnit is meticulously crafted to keep the audience constantly surprised. While this quality holds more literary than theatrical significance, it stems from a well-established tradition in fiction—seen in the tightly constructed, intelligent narratives of authors like Ellery Queen, Agatha Christie, Raymond Chandler, Dashiell Hammett, John le Carré, and Eric Ambler, among others in the detective and spy genres. Similarly, playwrights such as Ira Levin and Agatha Christie herself, particularly in stage adaptations of her stories like The Mousetrap and Ten Little Niggers, display the same deliberate artistry. This attention to intricate plotting also appears in works by Anthony Shaffer and other dramatists, especially English-speaking writers from the 1930s to the 1960s who anticipated their plays being adapted into Hollywood films, including Sidney Kingsley and J. B. Priestley. But what makes this play by Anthony Shaffer different from other similar works, even his own works, is that it is derived from the metatheatrical tradition, which makes it have a specific theatrical form achievement. The nature of this study is structural-formal and its aim is to examine the hidden characteristics and achievements of generic works. The case study here is the play Whodunnit by Anthony Schaefer. In addition, examples from other generic and metatheatrical plays will be mentioned to examine the formal and thematic commonalities of this form of theatre. The research hypotheses are as follows: -Generic works are not necessarily conservative and can act as revolutionaries if the rules of the genre are applied intelligently in them. -The play-within-the-play in the play Whodunnit is the intelligent tool that saves this play from conservatism. -Since the play-within-the-play is one of the tools that can turn a work into a metatheatre, the present work must be viewed within the framework of a metatheatre in order to realize its revolutionary achievements and values ​​in terms of form and thematic theatre. Since Whodunnit is a play that uses the ‘play-within-a-play’ device, it should be noted that this device has generally appeared and been used in different ways throughout the history of drama. One form of using the ‘play-within-a-play’ form is the play Mousetrap in Shakespeare's Hamlet and Brecht's The Caucasian Chalk Circle, in which a conscious play is performed with a specific intention: in the first to determine whether Claudius is guilty or innocent, and in the second to tell an allegorical story in order to make a correct judgment. These two examples have a subtle difference in the use of this form. In Shakespeare's play, the present tense takes up most of the play, and Hamlet's performance lasts no more than ten minutes. In Brecht's play, the present tense is limited to a few minutes at the beginning and a few minutes at the end, and the play that is performed in it takes up most of his play. Another form of using the ‘play-within-a-play’ form can be seen in plays such as Mephisto Forever by Tom Lanoye, Noises Off by Michael Frayne, and The Real Inspector Hound by Tom Stoppard. In this second form, a theatre group is performing a play for performance; in other words, it is not intended to have a function outside the theatrical medium, as in the first type of this form. In fact, Hamlet intends to perform the play to gauge Claudius' reaction, and the performers in The Caucasian Chalk Circle present their play to influence the judges who have come from Tbilisi to the village; but in this second use of the ‘play-within-a-play’ device, the inner play is not merely a tool but an end in itself. Since, in Abel’s view, not all plays he considers examples of metatheatre make use of the device of the ‘play-within-a-play,’ the term cannot be used to refer exclusively to this form of theatre. For this reason, he adopts the term metatheatre. In his opinion, metatheatre refers to a clear and definitive theatrical mode, rather than merely a theatrical device of expression. This study aims to demonstrate that in genre-based plays, the effective application of various techniques embeds the central idea or theme more deeply within the work. When these methods are seamlessly integrated into the overall narrative, they avoid being reduced to mere formal devices. Such plays are frequently criticized as conventional, often assumed to serve only an entertaining function. Yet, a more careful analysis—particularly one focused on their technical aspects—reveals significant formal and structural accomplishments within the theatrical medium. Therefore, it can be said that Schaefer's play, although considered a generic play, was never a conservative one, and by using ‘play-within-a-play’ technique and changing its rules through the creation of a third play (the inspector's play), it adds another level to the already known levels of this technique and, ironically, acts as a revolution.