Over on Geekdom.Social, someone asked about writing a script treatment. I don’t think there’s any hard rules for this one – the standards vary depending on who you’re submitting to and how far along you are as a writer in this business. Always check with agents to see what they want in terms of formatting.
Lots of script sites offer up examples of screenplay treatments, but those vary from ‘raw first draft’ to seasoned and details ‘scriptments’ from directors who’ve proven their stuff and are no longer bound by KISS (keep it simple stupid) rules.
I have a first-draft treatment up for We’re Not Brothers – a psychological gay love story set in a Poland overrun by zombies. My method isn’t law, so again, always check agent pages, the WGA web site, or the production company putting out an open call.
Just tell your story scene by scene, as basic as you can, and then add details later. My online example needs a trim, but you get the idea. Most reps prefer a 12 pager (not including the title page) but I typically go 12-14 pages.