10 Movies That Struggled To Define Their Own Rules

Time travel is one of the toughest concepts to write in all of fiction, if only because it opens a given project up to a litany of plot holes inherent in the nature of time travel itself.

But many time travel films at least manage to maintain an internal consistency by laying down some ground rules upfront and sticking to them for the rest of the movie.

Then there's The Butterfly Effect, a film which from its title onwards is clearly interested in the nature of causality, of how a minor event in one's life can redefine the rest of it, but ultimately ends up tripping over its own non-logic.

When protagonist Evan (Ashton Kutcher) ends up in prison, he attempts to convince his cellmate of his time-traveling abilities by revisiting his childhood and injuring his hands, causing stigmata-like wounds to appear before his cellmate's eyes.

Except, of course, the movie's laws of time travel would indicate that the scars would've been present on his hands the entire time, rather than just instantaneously appearing when the movie needed them to.

Furthermore, per the entire thematic of the movie, young Evan stabbing his hands likely would've altered the course of his life in a number of ways, possibly preventing Evan from going to jail and almost definitely ensuring he wound up with a different cellmate.

As much as this is effectively a time travel film marketed towards the CW crowd, it's still pretty patronising that it asks the audience to ignore a blatant disregard of its own established rules of causation.