Throughout the past seventy years of mainstream cinema, trailers have always been the predominant form of marketing for film.

Even 76 years ago, Gone with the Wind and The Wizard of Oz were promoted through radio ads, trailers in a sense. Now, whenever a new trailer is produced for an upcoming film, it is shared by millions on Facebook, reaching the audiences who do not normally attend the cinema yet do use the internet.

Recently, the latest trailer for a little film coming up called Star Wars: The Force Awakens premiered. Having previously released a teaser and a subsequent trailer, this new trailer delves into the plot of The Force Awakens more than the previous two trailers, which had the primary purpose of reminding the world that Star Wars was not dead. This latest trailer introduces Daisy Ridley’s character Rey as the primary protagonist, sets up Kylo Ren as the villain following in Vader’s footsteps, and sets a tone of nostalgia with Han Solo’s presence yet also reaffirms that The Force Awakens will not merely be a feels trip, which was the greatest cause of concern. In essence, The Force Awakens trailer is perfect, showing the main characters, a powerful villain, and a taste of the incredible and visually stunning space battles The Force Awakens is sure to offer.

This calls into question what makes a good trailer.

A good trailer gives hints of a film yet does not reveal all of the magical moments. As a piece of marketing, it is imperative to draw in a broad audience so as to increase revenue.

Yet so many trailers feature Easter eggs to appeal to hardcore fans, like the Prometheus trailers with shots of the ships from the original Alien scattered throughout. One of the best trailers in recent years was the first trailer for The Hobbit: An Unexpected Journey. Leading in with the classic Shire theme from Lord of the Rings, the trailer begins with old Bilbo Baggins, played by Ian Holm from Lord of the Rings, narrating about his younger days before transitioning to sixty years prior, with young Bilbo Baggins played by Martin Freeman. In the course of the next two minutes, the dwarves of Erebor quest is revealed, and Bilbo’s opportunity to go on an adventure is touched on, ending with snippets of action sequences later on in the film with an epic score original for The Hobbit films, not from Lord of the Rings.

In two and a half minutes, An Unexpected Journey establishes that the prequel to Lord of the Rings is in the same spirit of dark fantasy yet an independent story with dynamic characters and excellent action. While An Unexpected Journey disappointed many fans, the trailer was constructed perfectly and hit all of the notes it had to.

Consider last year’s event film Interstellar. The first trailer was merely a compilation of stock footage of space shots with Matthew McCoughnahey narrating some dialogue. The only actual footage shown from Interstellar was a truck driving through a cornfield. While the trailer might have captured the theme of Interstellar, it did not do a good job of portraying the story, scope, and execution of the final film, as there is nothing shown at all.

Sometimes, a trailer can be an independent narrative itself. By far, the best trailer of the year is for the upcoming film The Revenant. Starring Leonardo DiCaprio, The Revenant is a period drama based off the true story of frontiersmen Hugh Glass, and his quest for survival and revenge after being left for dead from a bear attack. The trailer captures the shots of the Canadian wilderness and the detailed, gritty feel of the characters.

When Hugh starts panting, the panting develops into a continuous beat that sets the mood for a pulse pounding, riveting survival tale that will surely be dark and gritty. Yet what The Revenant trailer captures the best is the beautiful cinematography in the form of long shots of battles between frontiersmen’s and Indians.

At the end of the day, a trailer is just as subjective as film itself. Yet in a day and age where there are more films coming out than ever before, it is imperative that trailers do a good job conveying the film they are trying to promote without giving away too much information. Write in what your favorite trailers of the year are!