The logline is truly an art form of its own. It’s the one or two sentence summary of your film that not only conveys your premise, but also gives the reader emotional insight into the story as a whole. Loglines were used in the early days of Hollywood so producers could read a short explanation of a script (most often printed on the spine of the screenplay), allowing them to skip over disinteresting screenplays without even pulling them out from the shelf. While loglines today are no longer printed on the screenplays themselves, they effectively serve the exact same purpose – to efficiently represent the story and get the potential reader interested.

Here’s a quick example. This is the log line for Steven Spielberg’s ‘Jaws’:

A land lubber sheriff tries to kill a giant shark to protect his family and seaside resort town.

It’s important to note that while it’s critical to have a good logline so that you can concisely explain your film on paper, it works just as well verbally. If you’ve ever tried to explain your entire feature film to someone in one sentence, you’ve surely found that it can be quite challenging. After all, it simply isn’t possible to convey every last detail of a 110 page script in a sentence or two. And unfortunately when dealing with anyone that can really do something for your film, all you might have is a sentence or two worth of time to get your idea across. That’s okay though because you don’t need to give away the entire story – in fact you shouldn’t. The goal is to sell the idea of the script, rather than the story itself, and the most effective way to do this is with a strong logline.

While the logline can serve you well both in written form and verbal form by getting the attention of producers, readers, agents, and anyone else you may want to interest – you also need to take into account the benefit a strong logline has on yourself as a writer. Screenwriting guru Blake Snyder has often referred to the log line as the DNA of your film, and I believe that statement to be very true. If you have a perfectly constructed logline that genuinely taps into the essence of what your film is all about, then it’s meaning should resonate on every page of your script. If you’re ever stuck writing a scene, you can always look to that logline and it will push you in the right direction. It helps you to maintain focus on what the core of the story is really about and ultimately your final screenplay should be a detailed extrapolation of it.

So we know the logline is just as important as a creative tool as it is as a vehicle to spark the interest of others. But what’s in a good logline? What’s the proper formula? Well there are dozens (if not hundreds) of valid formulas and options when it comes to structuring your logline, but there are certainly techniques that work better than others. I’ve personally tried a huge number of techniques and approaches myself and ultimately found the one that by far seems to work the best for me every time. Below I’ll break down this simple and extremely effective method, but before jumping into it, it’s important to recognize the key components that make a logline strong and the goal as far as your final structure is concerned.

Let’s quickly look at the most important components of a log line. Ultimately you need to get across the following information:

• The protagonist (don’t use their names, just description – for example ‘An alcoholic surgeon….’)
• The goal of the protagonist (this is usually in line with your 2nd act turning point – ‘An alcoholic surgeon must fight for his job…’)
• The antagonist (and the obstacle of the antagonist – ‘An alcoholic surgeon must fight for his job after a disgruntled patient accuses him of malpractice…’)

We also need to recognize how these components fit into the structure. Like I said before there are numerous formats you can use, and you should always adjust this to suit your particular story. But this structural formula is a great starting point:

When [INCITING INCIDENT OCCURS], a [SPECIFIC PROTAGONIST] must [OBJECTIVE], or else [STAKES].

While it may be tempting to simply take the formula above and plug in the details of your story, I would highly advise against it as it will never yield the best results. You will really want to take this one step further using the technique that I’ve outlined below, which involves working backwards to find the essence of your story. This isn’t a technique I created myself, but it is the one that by far has given me the most consistent results.

The method itself is extremely simple. You ask 4 questions about the story of your film starting from the end and working your way to the beginning. It should also be noted that when using this formula you generally don’t want to give away the third act, but rather tease the third act with points from the first and second. In other words none of your questions should pertain to anything after the 3rd act break.

When I came across this method, the example of ‘Back To The Future’ was used, so I’ll reference it here verbatim. Here are the questions that were asked and their subsequent answers:

• How can Marty come back from the past? (He has to reunite his parents)
• Why did he have to reunite his parents? (Because he has changed the past which drove them apart)
• Why did he change the past? (Because he accidently distracted his mother from noticing and falling in love with his father)
• Why did he find himself in the past? (To save his skin using the invention of a crazy scientist)

Now that you have your answers you can construct a rudimentary outline of what will eventually become your log line:

“A young man, to save his skin, hides in the past thanks to the invention of a crazy scientist. He meets his future parents and accidently distracts his mother from noticing and falling in love with his father. So he is forced to bring them together or he will cease to exist.”

The key is of course to make it less clunky and more focused, leaving us with something like this:

“A young man is transported to the past where he must reunite his parents before he and his future are no more.”

The Who, What, When, Why and How will always force us to explain the most important parts of the story, which is why this method works so well. It’s not an exact science and it’s of course still up to you to decide which questions are most important to ask, but I find that as long as you ask questions related to the turning points in your story, you’ll be fine. For instance your first question should be pertinent to the 3rd act break and the final question might relate to your opening image or catalyst moment. Following these general rules will put you in the best possible position to understand the fundamentals of your screenplay.

Finally I will re-iterate point that the purpose of writing your log line isn’t to sell your story, it’s to sell the idea of your story. You just want enough information to get the wheels spinning in the mind of your reader and get them ready for more. And once again, the log line is just as much for you as it is for your reader. If you have a weak, unfocused log line before you even write your script, chances are your script isn’t going to turn out well. It’s the seed of your idea and it needs to be as focused as possible to allow your story to have the best possible starting point.

For more on writing, check out my popular article ‘5 Tips For Writing Better Characters Into Your Screenplay’.