A breakdown turns a screenplay into lists. Every scene gets a sheet, every sheet says what the production has to put in front of the camera, and those lists feed the schedule, the budget, and each department's prep. The order is strict. You can't break a script down until the scenes are numbered, and the schedule can't use your sheets until each one has a page count.
Numbers and eighths come first
Read what is a script breakdown once for the overall picture, then go back to the two mechanical steps that happen before any marking.
Scene numbers first. How to number a film script for production explains when numbers go in and why they don't change after that. Once the basics are clear, scene numbering rules handles the awkward cases: intercut phone calls, montages, two scenes merged into one. Look up A-scenes and omitted scenes too, because you'll see "42A" and "OMITTED" on real shooting scripts long before anyone explains them.
Then page counts. How to calculate script page counts in eighths teaches the eight-band method. Do a few pages by hand and check yourself with the page count calculator. A 1 3/8 page scene and a 3/8 page scene can read about the same on a quick pass, and they schedule very differently.
Marking the script and filling in sheets
With numbers and eighths done, learn the categories. The color codes chart gives the usual convention (red for cast, orange for stunts, green for background, purple for props) and how to mark a page in passes. Then go field by field through how to fill out a script breakdown sheet with the breakdown sheet template open next to it. Script breakdown example takes one scene from the page to a finished sheet, which is a quick way to check whether you've understood the steps.
The script day field is easy to skip on a first breakdown. Read the script day entry before you start a breakdown of your own, since wardrobe and hair and makeup build their continuity plans on it.
The categories scripts don't spell out
Some elements aren't written plainly. Background is the usual problem: the script says the bar is packed, and someone has to turn that into a number with descriptions. Extras breakdown shows how, scene by scene and then by shoot day. Action scenes need their own pass to separate stunts, practical effects, and visual effects, and breaking down stunts, SFX, and VFX does that beat by beat for one scene, including what the split does to the schedule and budget.
After those, look at what departments build from your sheets. The prop list and wardrobe breakdown templates show how the prop master and costume department take your element lists and add multiples, story days, and costs.
When the script changes
Scripts change all through prep. Script revision colors covers the page color order (white, then blue, pink, yellow, green, goldenrod, and on) and what a revision means for sheets that are already done. The habit to build is reading the revision memo and updating only the scenes it touches.
Software, AI, and scripts that aren't screenplays
You can break down a script with colored pencils, in Final Draft, or with software that reads the file. How to break down a script in Final Draft 13 covers Tags Mode and where Final Draft stops being enough. Read AI script breakdown before you trust any automated tool. It lists what extraction tends to miss, such as implied multiples, counts of extras, and stunts buried in action lines, and it gives a scene-by-scene review pass.
Documentaries and music videos have no screenplay. If that's your work, documentary script breakdown builds shoot blocks from an outline, and the music video breakdown maps the song by timecode before pulling setups from the treatment.
Where the breakdown goes next
A finished breakdown is what the stripboard is built from, so continue with shooting schedules. When you're ready to price the elements you've listed, go to film budgeting. For the whole prep sequence and where the breakdown sits in it, see pre-production.