Teaser trailers generally serve as a short glimpse into an upcoming blockbuster movie, suggesting the tone of the finished film and giving audiences a hint of what the plot may be. The first teaser trailer for 2016's highly anticipated Rogue One: A Star Wars Story (Gareth Edwards) introduced its protagonist, Jyn Erso (Felicity Jones), as she is brought in chains before the rebel leaders. Mon Mothma (Genevieve O'Reilly) describes her as "on your own from the age of fifteen, reckless, aggressive, and undisciplined." Erso looks on, defiant and unapologetic. "This is a rebellion, isn't it?" she responds, "I rebel."

It's a powerful and effective way to establish a new character in a beloved franchise, setting the darker tone of Rogue One in contrast to previous movies in the Star Wars universe.

It's also not in the film.

After the release of Rogue One, fans were quick to notice that many images and set pieces promoted in the trailers were not in the finished product. 2015's The Force Awakens (J. J. Abrams) similarly contained moments that only existed in the advertising – noticeably, the character of Luke Skywalker (Mark Hamill) provides a voice-over to one trailer yet has no dialogue in the film. While these marketing practices could be accused of being deceptive to audiences, these teasers may function more effectively as advertising than trailers, which are often criticised by both audiences and directors for giving away too much of a film's story in advance. Instead, by focusing on tone, teaser trailers can attempt to both pique an audience's interest as well as capture the 'feel' of a film as the director intended.

Trailers for Rogue One prominently featured a moment where a wounded Erso faces an Imperial TIE fighter aiming straight towards her. This, again, was nowhere to be found in the film itself. As Entertainment Weekly's Anthony Breznican reports, "The hovering TIE was an image without a story point, and it only existed for the sake of the trailer, capturing the David vs. Goliath tone of the nascent Rebellion and the overpowering Empire."1 Director Gareth Edwards acknowledges, "It was something the marketing team fell in love with . . . we knew it would not be in the film." J. J. Abrams, who directed the first major Star Wars film in fifteen years with The Force Awakens, also discussed the difference between the marketing of his film and the finished product: "There might be a look or scene in a trailer that identifies as being powerful in that short form, but sometimes that doesn't jibe with what's happening in the long form."2 Abrams and his production company, Bad Robot, have a strong track record of raising audience expectations with mysterious, vague marketing that shows little actual footage – with Robbie Collin going so far as to name him "[the] Grand Vizier of the new Age of Maybe" for the mysterious marketing surrounding the Cloverfield series.3

Matt Reeves' Cloverfield (2008), produced by Bad Robot, was first announced with a deliberately ambiguous trailer. In it, shaky, hand-held footage of a man's going-away party is interrupted by an earthquake, followed by an animalistic roar, a distant explosion and the head of the Statue of Liberty crashing to the ground. Abrams' producer credit flashes onto the screen, followed by a release date with no title. As Carrielynn D. Reinhard reports:

The trailer did its job of energizing fans of Abrams' work, as the Internet was soon abuzz with speculation and attempts to find spoilers. By the time Abrams revealed more information a month later . . . it was known to be a monster movie with various tentative titles circulated to confuse potential spoiler spies.4

The anticipation helped make Cloverfield a success, earning US$170.8 million at the box office against a budget of $25 million. Similar tactics were used for the follow-up film, 10 Cloverfield Lane (Dan Trachenberg, 2016), with a trailer released only two months before the release date that only hints at a link to Cloverfield through its title. Secrecy around the film was so tight that "even its stars, John Goodman and Mary Elizabeth Winstead, weren't told the film's real title until a week before its one and only 90-second trailer was released."5

Collin notes the influence of Alfred Hitchcock on Abrams and Bad Robot's mysterious style of marketing, particularly the now-famous mystery Hitchcock built up around his most famous film, Psycho (1960). The Psycho trailer consisted of no footage from the film, just Hitchcock taking a tour through the film's locations. In each location, he starts describing events and then, very deliberately, stops himself from revealing what happens in each room. The tour ends in the bathroom, with Hitchcock pulling back the shower curtain as the audience hears a woman screaming. Collin describes how "by the advertising standards of the day, Hitchcock's fumbling, evasive commentary was next to useless," and yet "the end result: ticket sales soared."6 These examples demonstrate how establishing tone can be a more effective marketing tool than accurately presenting the plot – as the trailers for Cloverfield and Psycho establish their films as a grounded monster/disaster movie and a crime/horror film while showing minimal footage from the actual film.

Notably, Hitchcock and Abrams are both creative producers who have significant input in both the story and the marketing of their films. This hands-on approach to marketing can be contrasted with directors of other blockbuster films who didn't have such an active role. Terminator: Genisys (2015) director Alan Taylor reportedly felt that "the trailer-makers were inappropriately messing with expectations,"7 openly criticising the marketing for revealing a key twist in the film. Similarly, Colin Trevorrow complained how trailers for his Jurassic World (2015) featured a shot of star Chris Pratt with seemingly tame velociraptors without context, stating: "If you just show people snippets of something . . . without them understanding the set of rules that define the movie . . . it can be challenging for an audience."8 In both of these cases there was a division between the creative and the business elements of the films – with the marketing team depicting shocking or exciting moments in trailers to get audience attention that ultimately misrepresent the story being told by the directors in the finished film.

While certain lines or shots featured in the Rogue One trailers may not have been included in the film itself, the feeling of underdog rebels fighting an overpowering Empire in a darker Star Wars story was evident from the first teaser. Trailers that do little more than establish a clear sense of tone can be even more effective at piquing audience interest than trailers that misrepresent a film's story through not providing proper context for major moments or prematurely revealing plot points – thereby spoiling the audience's experience of seeing it fresh. By giving audiences the feeling of what a movie may be while forcing them to see it themselves to know for certain, the teaser trailer is most effective when the audience is literally teased with what they may never get to see.