Screenwriting : When do you write the log line: Before any writing starts, During or after it is completed? by Ann Burr

I usually come up with the logline first, (even though I have an idea of the story in my head.) The logline sort of serves as a "true north" for me, keeping the story on track- the promise of the premise.

Always write a solid version of the logline first. If you have trouble with the logline you have story issues that need to be resolved before typing FADE IN.

Personally, I suggest writers write a logline as soon as they have their concept and character and general story idea. It may change once (or after) you write the script, but then you can go back and see what your initial concept/story was and why it has deviated and if that's a good thing. Or if you've exploited that concept and story strong enough in the script. It can be a good guide as you write.

All of the above.

The logline isn't the paint. It's the foundation. If the script evolves during the writing, then of course, revise the logline. But I'd never walk into a house without a foundation, and I wouldn't start writing a script without a logline. This is, of course, my process. Some people might place a character in a situation and start writing and see what happens. Possibly good scripts have been written that way. I couldn't do it.

I agree with several of the above comments. I believe that the Logline or Premise should be arrived at before you start writing your screenplay. You may consider the Premise/Logine ato be your story's compass and necessary to provide direction as you proceed in your writing. When your story changes (and rest assured that it will) and if you accept those changes, then i suggest you now realign your "compass" to what your story has now become. Otherwise, you will be writing to a story that no longer exists in the way you originally intended. And every "fix" will draw your story further and further out of shape.

@ Kerry, why on earth is the logline the foundation? What about it has any support aspects at all? The logline is nothing but the For Sale sign in the front yard after the house is built. It's necessary but hardly an integral part of the structure.

I would say after... You will know for sure what the whole story is about and you'll know a lot more about your characters as well.

Disagree, Trey. It is a fundamental description of what your story is about. I've seen it a few times on these boards over the past couple of months: people struggling to write a logline, when what they're really struggling with is that they don't understand their own story. If you're writing a different logline to pitch your story with... well, okay. But you should be able to come up with a logline-style description of your story before you start writing. In my opinion. Obviously others work differently, and if they're successful with that, who am I to say they're wrong?

I agree, if that is what works for you then its the right thing for you to do. That wouldn't work for me, the logline is something I think about after the first draft is done.

I think the log line come out of your idea at the beginning during the creation of your idea and what its about.