Your logline must include the story element that hinders the main character from achieving their goal.
Antagonist Force - All good storytelling includes conflict.For example, the question in Star Wars is “In a galaxy far away, will a young farmer from a desert planet master his dormant powers to save humanity from a world-destroying battle station, while also attempting to rescue a Princess from the powerful and mysterious clutches of an evil warlord?” Turn the question into a statement and you have a log line. Goal - What does your main character want? This is often kickstarted from the inciting incident that leads to the conflict and ultimately the question of your film.Concentrate on character revealing adjectives which can give the reader a window into the main character’s emotional state, such as “a grieving father” or a “lonely architect”. Protagonist - Don’t get bogged down in names which crowd the logline (unless it’s a biopic and the person is well known).This all may sound easy, but distilling the complexities of your screenplay into two lines can often be a challenge.
If your film is genre based, you may also have to include a brief set-up that gives context to the world. A logline is a one or two line pitch of your story structure (usually under 40 words) that clues the reader into who is driving the narrative (the protagonist), what they want (the goal) and what stands in their way of getting it (the antagonist force).