The reasons why an actor might be cast in a role for which they are ill-suited are many and varied. It turns out, the first movie trailers occurred not at the beginning of the films, as they do today, but rather at the end of the films. The first known movie trailer to appear in a theater was in November of 1913. The most common trailer format today is the three-act structure, very similar to the structure of most films and plays. For the final Bonus Fact today, the maximum allowed length for any movie trailer shown in theaters or on TV is set by the MPAA.