The fourth wall is of course the perspective from which the audience witnesses a movie unfold, and as per typical filmmaking convention, the actors don't draw attention to this invisible line or make any attempt to interact with the audience.
But of course, some movies, especially comedies, do indeed make an active effort to break the fourth wall and address viewers, be it by way of a wink-wink gag or straight-up directly speaking to them as though it were a one-on-one conversation.
Fourth wall breaks are generally played for laughs, yes, but every so often it can actually have a significant impact on the plot, or better yet, drastically affect the fates of the movie's characters.
These 10 movies all condemned characters, be they heroes or villains, protagonists or minor characters, to grim ends, be it a brutal death or a lifetime in jail.
But had each film maintained the fourth wall that conventional cinema demands, these characters' fates would've all fared decidedly more favourably...