Movie trailers are a part of every movie experience. But who decides which ones you’ll see? Does the film studio do that…or the theater owner? Both.

First off, a trailer that starts with a green background is okay for all audiences and a red background is meant for mature audiences. You’re not going to see one of these red themed trailers, for example, before a Smurfs movie.

Let’s say the theatre is showing the latest “Star Wars” film, then it will also show trailers for upcoming Disney movies because the the studio that produces “Star Wars” is a part of Walt Disney Studios.

The theater owners can also choose to show certain trailers, naturally the movies it plans to screen later. And the theatre owners usually decide how many to show, it could be one or as many as eight, but audience surveys show that’s way too many.

And the National Association of Theater Owners decided that movie trailers should be no longer than two minutes each, but the studios are allowed two exemptions each year, if you’ve got a “Titanic” or “Avatar” coming out, the trailer can be three minutes.