What Is a Slugline? Scene Headings Explained
A slugline is the capitalized line that opens a scene, in the form INT. MOTEL ROOM – NIGHT. It carries three things, and most of what a schedule does downstream depends on them.
Also called: scene heading · scene header · slug line
The three parts
INT or EXT says whether you are inside or outside, which decides whether weather and daylight are your problem. The set name is what groups scenes into locations. DAY or NIGHT decides when in the day you can shoot it.
Some sluglines carry more. CONTINUOUS and LATER show up often. A few carry both sides at once, as in INT./EXT. CAR – MOVING – NIGHT, which is a driving scene and a scheduling headache in equal measure.
Why a parser cares
Software reads sluglines to build the scene list. Keep them consistent and an import gives you a clean scene per slugline with interior/exterior, set and time already filled in.
Keep them inconsistent, so the same room turns up as KITCHEN, JOHN’S KITCHEN and INT KITCHEN, and you get three locations where there is one. Then the schedule sends the unit back there twice for no reason and nobody can work out why.
Formatting
All caps, INT. or EXT. with the period, a dash before the time of day. Final Draft enforces it. Fountain and plain PDF do not, which is why an imported script sometimes needs a tidy-up pass before it will schedule cleanly.
