For the vast majority of movies, that very first trailer is the most important piece of marketing they'll send out into the world.
Those initial glimpses at the film will introduce audiences to the tone and style the director is going for, and if they don't like what they see, then a lot of people might not even bother watching the second trailer, let alone pay to see the film itself.
Important as they are, these early teasers and trailers are also at a slight disadvantage within the grander marketing timeline. Because they come out months - sometimes even a whole year - before the films they're representing, a lot can change in that time, and they can quite often include footage that doesn't make the final cut.
While scenes from the trailer not making it into the film is a common occurrence in this day and age, we very rarely hear the creators chime in and discuss exactly why this happens, but in the following cases, we were offered some solid reasons, directly from the mouths (and keyboards) of the filmmakers themselves.
8. Strange Has A Drink (Doctor Strange)
One of the most crucial moments in Doctor Strange is the car crash scene, the accident which results in Strange sustaining some life-changing - and, with the events of the last two Avengers flicks - universe-changing injuries.
Realising just how critical this moment was, director Scott Derrickson smartly removed a quick shot from the movie, one that would have completely changed the context of the scene.
Per the movie's trailers, the shot shows a suited-up Strange enjoying a glass of liquor while looking out of his apartment's massive windows. Had this stayed in the film, it would've implied that Strange's crash was caused by drunk-driving, but Derrickson didn't want this to be the case.
Rather, the director wanted the sole cause of Strange's accident to be his over-confidence, and so, he removed any traces of the character consuming alcohol before stepping behind the wheel.
Strange's whole journey is about him transforming from a selfish egotist into a compassionate protector of the universe, so having that same ego be responsible for his injuries was a good move, to further reinforce why he needed to change.