In a script, INT. means interior — the scene happens indoors — and EXT. means exterior, outdoors. Together with the location and the time of day they make up the scene heading, or slugline: a line in capitals such as INT. BAKERY - NIGHT that opens every scene.
Scene headings do more than set the stage for a reader. A production breaks a script down heading by heading: each one tells the crew whether to light a set or chase daylight, where to send the trucks and which scenes can be shot together. That is why they follow strict rules.
What is a slugline?
A slugline is another name for a scene heading — the capitalized line at the start of a scene that states interior or exterior, the location and the time of day. Writers use the two terms interchangeably. Some also use "slug" for the short secondary headings described further down.
The three parts of a scene heading
- INT. or EXT.: where the camera is — inside or outside. Write the abbreviation with a period.
- Location: the place, in capitals, moving from general to specific with a dash or a comma — FARMHOUSE - KITCHEN. Name it the same way every time you return to it.
- Time of day: usually DAY or NIGHT. MORNING, DUSK, DAWN or a clock time are fine when the difference matters to the story or the shoot.
The parts are separated by a space after the period and a spaced dash before the time of day:
INT. FERRY TERMINAL - WAITING ROOM - NIGHT EXT. HILLSIDE VINEYARD - DAWN INT. HOSPITAL - STAIRWELL - DAY
What does INT./EXT. mean?
INT./EXT. marks a scene that plays both inside and outside, or that moves across the threshold during the scene. The classic case is a moving car, where we see the driver through the windshield and the road around them; a doorway conversation or a porch is another. Some writers shorten it to I/E. Use it only when the scene genuinely needs both — otherwise pick one and add a new heading when the characters cross over.
INT./EXT. DELIVERY VAN - MOVING - NIGHT Wipers beat. NADIA (30s) drives one-handed, eating cold noodles from the carton.
CONTINUOUS, LATER and MOMENTS LATER
CONTINUOUS replaces the time of day when a scene follows straight on from the one before with no time cut — usually a character moving from one space to the next. LATER means time has passed in the same location, and MOMENTS LATER means only a little time has passed.
INT. APARTMENT - HALLWAY - NIGHT Nadia shoulders the door shut and runs for the stairs. INT. STAIRWELL - CONTINUOUS She takes them two at a time. INT. APARTMENT - HALLWAY - LATER The door stands open. The hall light is out.
Other variations you will see include SAME (two places at the same moment, often before an intercut) and specific labels such as THE NEXT MORNING. Use them when they help a reader follow time; leave them out when DAY or NIGHT says enough.
Secondary headings
A secondary heading is a short slug, in capitals at the action margin, that moves the scene to a new area within the same location without repeating INT., EXT. or the time of day. It keeps a long scene in one house or one ship readable without breaking it into a dozen full headings.
INT. OLD MILL - NIGHT Machinery under dust sheets. Nadia's torch beam swings. UPSTAIRS Floorboards give under her weight. Something rolls away in the dark. BACK DOWNSTAIRS The door she came in through is now shut.
Secondary headings work best when the geography is already clear. If the move changes the light, the time or the world outside, write a full scene heading instead. A single-location script such as The Locked Room shows how far one setting can go.
Establishing shots
An establishing shot shows the outside of a place before we cut inside it, so the audience knows where they are. In a scene heading it is usually written by adding ESTABLISHING to the heading, followed by a line of action at most:
EXT. LIGHTHOUSE - ESTABLISHING - DAWN INT. LIGHTHOUSE - LAMP ROOM - CONTINUOUS The keeper polishes the lens without looking at it.
Use establishing shots when the place itself carries information. Many directors decide on them anyway, so a spec script does not need one before every scene.
Scene headings in a shooting script
When a script goes into production, each scene heading gains a scene number in both margins, and from then on the numbers are locked. A scene added between 12 and 13 becomes 12A; a scene that is cut keeps its number with the word OMITTED, so the schedule and the call sheets never have to be renumbered. The heading text itself also matters more at this stage: the assistant director's breakdown groups scenes by INT. or EXT., location and day or night, so a heading that names a place two ways can end up scheduled as two different locations.
How to write a scene heading
- Start a new line at the left margin with one blank line above it.
- Type INT. or EXT. — or INT./EXT. if the scene truly spans both.
- Name the location in capitals, general to specific, exactly as you named it before.
- Add a spaced dash and the time of day, or CONTINUOUS, LATER or MOMENTS LATER.
- Follow it with action, never with dialogue — the reader needs to see the space before anyone speaks.
- Check the page: a scene heading must not be the last line at the bottom.
Common scene heading mistakes
- Naming one place two ways (KITCHEN, then JO'S KITCHEN). Readers lose track, and every location list built from the script counts two places.
- Leaving out the time of day, so the reader cannot tell when the scene happens.
- Putting action into the heading, as in INT. BAR - NIGHT - SHE WALKS IN. Keep the heading to place and time.
- Using a new full heading for every step around one room, where a secondary heading or plain action would do.
- Writing headings in sentence case. They are always all capitals.
Flashbacks, dreams and montages add their own labels to the heading; the montage and flashback guide covers those, and the screenplay format guide covers the rest of the page.
Write it in Scenaloom
In Scenaloom a scene heading is its own element — pick it with Tab on an empty line or a keyboard shortcut, and Enter after a transition starts one for you. Press Enter at the end of the heading and you are on an action line underneath. Scenaloom builds your locations page and scene list from the scene headings, so naming a place consistently means it appears once with all its scenes. Scene numbers can be switched on and locked for production. Start a script and the headings format as you type.
Questions
What does INT. mean in a script?
INT. stands for interior: the scene takes place indoors, or the camera is inside a space such as a room, a car or a tent. It is the first part of a scene heading, followed by the location and the time of day, as in INT. KITCHEN - NIGHT. It tells the crew the scene will be shot on a set or an interior location.
What does EXT. mean in a script?
EXT. stands for exterior: the scene takes place outdoors, such as a street, a field or a rooftop. Like INT., it opens the scene heading — EXT. HARBOR - DAWN — and tells the production the scene depends on outdoor light and weather. A scene that moves between inside and outside uses INT./EXT.
When do you use CONTINUOUS in a screenplay?
Use CONTINUOUS in place of the time of day when a scene follows directly from the previous one with no time skipped — typically a character walking or running from one location into the next. It tells the reader the action is unbroken. If time has passed in the same place, use LATER or MOMENTS LATER instead.
What is the difference between LATER and MOMENTS LATER?
LATER means a noticeable stretch of time has passed in the same location — minutes or hours. MOMENTS LATER means only a short gap, such as the time it takes for someone to answer a door. Both replace DAY or NIGHT in the scene heading and both imply the same location after a small jump in time.
Should scene headings be bold?
Scene headings must be in capitals; bold is optional. Some writers bold headings to make scenes easier to find on the page, others leave them plain, and readers accept either. What matters is consistency — every heading in the script should look the same.