The rules that define any medium at any particular point in time may vary in complexity, but they are still binding. If the medium you’re playing around in is space travel, you should probably pay strict attention to the rules we call the laws of physics. On the other hand if the medium you’re playing around in is abstract sculpture, you can pretty much do anything you want as long as it ends up being a physical object — or, if your intended audience is purely intellectual or academic, some non-physical or negative-space meta-commentary on physical objects. If you try to present an action painting as sculpture, however, you’re probably going to get confused looks, if not some serious push-back.
The tendency over time is for all mediums to become more plastic. Rules that were previously assumed to be inviolate are challenged by artists and craftspeople who chafe at those limitations, until ultimately all non-essential rules are pared away to reveal the bedrock foundation of the medium itself. Like sculpture, a painting is defined today simply as any application of paint to canvas, board or wall. It doesn’t matter whether a painting is abstract or representational: all that matters is that the materials being used are paint or some paint equivalent, but that clearly wasn’t always the case. This creative freedom for painters was hard-won over centuries, with each subsequent school balking at restrictions imposed by those who came before, until, ultimately, all rules of what defines a painting were abandoned in favor of unbridled creativity.
And yet, as with sculpture, rules still apply no matter how plastic a medium becomes. If what you call a painting is in fact a pumpkin sitting in a field then you’re objectively wrong. You can do anything you want with paint, you can paint anything you want, or paint on anything you want, but without paint (or its equivalent) you don’t have a painting.
Compared to painting, storytelling as a medium — even in the rarefied air of experimental literature — is and will always remain constrained by complex rules. Some of these rules are a result of the way human brains take in and process narrative information. Some are cultural rules that define the meaning of objects and people and places before they are redefined or repurposed by authors. Some are logical rules having to do with time and place and order, which can only be broken when some plausible new rule (time travel, say) replaces the assumed rules so the reader does not become lost. And there are of course rules defined by language.
When authors say of literature that there are no rules, what they mean is that you can write about anything in any manner you see fit, as long as it pays off in the way you intend. If you see a literary objective and you need to break a specific rule to reach that goal you’re allowed to do it. What you’re not allowed to do is put ten thousand words in a blender, hit puree, and call that a story, or literature, or even a dictionary mash-up. If you do that with paint people may actually pay you for the result if you spew it on a canvas or sell it in gallon cans, but nobody is going to pay you for pureed words.
— Mark Barrett