Postmodernism and "Literature", Theater, Film etc.

The End of Realism
If language itself keeps humans from communicating about or even perceiving objective truth, then literature, which is formed entirely of language, should stop pretending that it can represent objective reality (including the "objective reality" of our subjective minds: our psychology). So, Postmodern literature breaks with Modern literature by breaking with Realism; it often stops pretending that it can accurately represent objective reality.  It is often, instead, interested in representing the problems associated with representation.

Meta-textual-ism and Play
Rather than pretending to offer an accurate objective representation of reality, Postmodern literature, theater and film often incorporate the elements of the following:

1) Uncertainty: Uncertainty itself may become the focus. Postmodern works are often interested in representing the key, faulty role language plays in shaping perception and self-identity.  Language itself -- as a means of understanding reality -- becomes the focus. See Memento, Pi, Rosencrantz and Guildenstern are Dead.  These films, as well as The Eternal Sunshine of the Spotless Mind also play with the role of memory and our relationship to the world, others, and ourselves.

2) Meta-textual-ism: The work of art is often aware that it is a work of art; it no longer mistakes itself for reality. Characters may be aware that they are characters in a work, or elements of book, film etc offer a commentary on itself as book, film, genre etc.  This usually implies a type of satire, like with Archer, or Community, in which entire episodes are commentary on the original work or genre, and the fun is simply in catching hidden references.  Also see Scream, Rosencrantz and Guildenstern are Dead, The Last Action Hero, William Shatner building a post-Star Trek career (starting with Airplane 2) on playing William Shatner playing Captain Kirk.

3) Other Realism elements become fluid, such as time (plot). See Pulp Fiction in which the last scene features characters already killed in previous scenes, and of course again Memento (and many of you have probably seen Inception, also directed by Memento's Christopher Nolan)...in fact, this approach is probably so common in contemporary film that y'all have grown up thinking it normal.

4) Perhaps the major feature of Postmodern works are their emphasis on play or games. The examination, rather than the remedy, of the Postmodern condition becomes itself the focus.  See Rosencrantz and Guildenstern are Dead, The Simpsons, Scream...none of these Postmodern works attempt new or "valid" solutions to the Postmodern condition: they simply "play" with the different philosophical perspectives and celebrate irony and wit as the purpose of the art itself.  As Foucault puts it, irony is the most logical response to the Postmodern condition: we witness the elements that don't add up, play with them, laugh at them, and move on.  Early Postmodern theater is often called "the theater of the absurd", representing the absurdity of life (that it doesn't always make sense), or the absurdity of art that tries to make sense, while later works seem more interested in constructing narratives like puzzles.  Jorge Louis Borges' "stories", for example, are not really stories at all, they are fictitious scientific or logic puzzles involving false analyses of non-existent books and theories.

Video Gaming and the Internet
For this reason, perhaps the best icons of Postmodern literature are to be found in video-gaming, You-Tube, Facebook, and the internet itself, including pornography: unlike traditional media missing in new media are larger, guiding thematic purposes; gone is character development;  gone is an attempt to understand psychological motivation; gone is the Meta-Narrative that guides a culture toward a goal and attempts to build itself as a coherent, unified culture.  Often gone is plot itself (although video games are essentially entirely plot).  Our Postmodern media does not try to tell a traditional story or steer the reader toward knowledge; in short, it has given up on meaning and many of the other guiding principles of art, literature etc., like coherence and plot.

Examples: The Hunger Games  NFL

The Death of the Author(ity)
In fact, missing in each is the author his or herself: thru the literary forms of the internet and gaming (especially online gaming) we are all primarily interested in playing with the narrative: writing it ourselves, and treating ourselves as characters in an absurdist play, celebrating the pointlessness of our own celebrity, creating personas for ourselves that have nothing to do with our working lives (Marxist alienation on steroids). See: Rap: word play, digital sampling of other works, irony, white suburban kids pretending to be urban black kids....

And if the product is utterly meaningless, all the better.

Truth Is Beauty and Beauty Truth
Postmodern art posits that freedom from Realism simply offers more means of exploring the human condition:  if we cannot understand the human experience entirely through Enlightenment rationality, than we are still free to explore other means. 

Art, in a word, can still express the ineffable, still attain or represent the sublime, and allow access to "truths" that are inherently emotional or perhaps spiritual.  We also see this in Stoppard's Postmodern reworking of Hamlet, (Rosencrantz and Guildenstern are Dead) and in Hamlet itself: where Hamlet's excessive intellectualism fails to aid him in addressing his deepest existential concerns, "the play's [still] the thing to catch the king";  the players' Murder Of Gonzago reveals Claudius' true nature not only to Hamlet but to Claudius himself. In other words, in the original Hamlet, we are shown that sometimes Reason fails us but art can lead us to the truth: watching the play

The Player seems to represent Stoppard himself, constantly reminding Rosencrantz and Guildenstern that beneath the tawdry edifice of their art rests a solid foundation of truth and the answers to the very questions constantly eluding R and C as they waste their verbage attempting rational answers to life's irrational predicament.

Similarly, Charlie Kaufman's films at first appear absurd but eventually reveal to the viewer a fairly powerful and sublime message about what it means to live, love, and die.  In The Eternal Sunshine of the Spotless Mind, for example, Kaufman jettisons realism for a science-fiction-based plot and a disorienting relationship to time and memory, but in doing so he is still able to plumb the depths of what it actually feels like to be in love and, more importantly, offer a deeply gratifying and meaningful examination of how to love well.  This is of course not entirely new and we can find similar fantastical stories throughout history, so many argue that Post Modernism simply returns the traditional fantasy world to its originally central place in our means of understanding reality.

Recently shows like The Good Place, Westworld and Altered Carbon have proven Postmodern approaches highly capable of confronting the same political issues that once compelled Locke, Voltaire and Rousseau or the issues Camus and Sartre etc. deal with.