Scene Headings (Sluglines)

Every scene in a screenplay begins with a scene heading, also called a slugline. This single line of text tells the reader (and eventually every department on a film crew) three things: whether the scene is interior or exterior, where it takes place, and when it takes place. Scene headings are always written in ALL CAPS.

They carry more weight than most beginning writers realize. An assistant director will break down your sluglines to create a shooting schedule. A location scout will use them to identify every unique setting in the film. A line producer will use them to estimate budget. Clear, consistent scene headings are one of the simplest ways to signal that you are a professional.

What Is a Scene Heading

A scene heading has three components, separated by hyphens: the interior/exterior designation, the location, and the time of day.

INT. POLICE STATION - INTERROGATION ROOM - NIGHT

In this example, "INT." tells us we are inside. "POLICE STATION - INTERROGATION ROOM" identifies both the general location and the specific room within it. "NIGHT" tells us the time of day. Every scene heading in a professionally formatted screenplay follows this pattern.

A new scene heading is required whenever the location or time changes. If your character walks from the kitchen to the living room, that is a new scene heading. If the story jumps from afternoon to evening in the same location, that is a new scene heading. Each scene heading represents a discrete unit of action in a specific place at a specific time.

In Ensemble, scene headings are automatically formatted when you type a line that begins with INT. or EXT., and the editor recognizes the pattern and applies the correct uppercase styling and spacing.

INT. vs EXT.

"INT." stands for interior - any scene that takes place indoors. "EXT." stands for exterior - any scene that takes place outdoors. This distinction matters for production (interior scenes require different lighting, sound, and location permits than exterior scenes) and for storytelling, because it immediately sets a spatial context in the reader's mind.

INT. APARTMENT - BEDROOM - MORNING
Sunlight bleeds through thin curtains. Sarah is already dressed, sitting on the edge of the bed, staring at her phone.

EXT. APARTMENT BUILDING - CONTINUOUS
Sarah pushes through the front door and steps onto the sidewalk. She looks up and down the street. No car. She checks her phone again.

When a scene takes place in a location that is both inside and outside (a car with open windows, a doorway, a patio with a roof) use "INT./EXT." or "EXT./INT." to indicate the mixed setting.

INT./EXT. MOVING CAR - DAY
Tom grips the wheel. Through the windshield, the desert highway stretches to the horizon. Nothing but sand and heat shimmer for miles.

Use "INT./EXT." when the camera needs to see both inside and outside, like a conversation in a car that also shows the scenery passing by. If the scene is entirely focused on the interior of the car with no exterior visible, just use "INT."

Always include the period after INT and EXT. Writing "INT" without the period or "Interior" spelled out are both non-standard and will mark your screenplay as amateurish. The abbreviations with periods (INT. and EXT.) are universal.

Time of Day

The time of day appears at the end of the scene heading, after the final hyphen. The most common values are DAY and NIGHT. They tell the DP what lighting setup to prepare and help the reader track the passage of time through the story.

EXT. HARBOR - DAY
INT. WAREHOUSE - NIGHT
EXT. SUBURBAN STREET - DAWN
INT. BAR - EVENING

Beyond DAY and NIGHT, you have several other options that carry specific meanings:

CONTINUOUS

Use CONTINUOUS when the action moves without interruption from one location to another. If a character walks from the hallway into the kitchen in real time, the kitchen scene heading uses CONTINUOUS. It tells the reader and the editor that no time has passed between scenes.

INT. OFFICE BUILDING - HALLWAY - DAY
Claire strides down the corridor, heels clicking on tile. She reaches the corner office and pushes through the door without knocking.
INT. OFFICE BUILDING - CORNER OFFICE - CONTINUOUS
PHILLIP DAVENPORT (60s) looks up from his desk, pen frozen mid-signature.
CLAIRE
We need to talk about the Meridian account.

LATER

LATER indicates that time has passed within the same location. You are still in the same place, but the scene has jumped forward, maybe an hour, maybe several hours. Use it when the passage of time is clear from context but you do not need to specify exactly how much.

INT. HOSPITAL WAITING ROOM - NIGHT
The room is packed. Every seat taken. David paces near the window, phone pressed to his ear.
INT. HOSPITAL WAITING ROOM - LATER
The room is nearly empty now. David sits alone, coat folded in his lap, staring at nothing.

SAME

SAME (or SAME TIME) is used for intercutting, when two scenes are happening simultaneously in different locations. It is less common than CONTINUOUS or LATER but useful for parallel action sequences or split-screen storytelling.

INT. BANK VAULT - DAY
Leo works the combination lock, sweat beading on his forehead.
EXT. BANK - PARKING LOT - SAME
A police cruiser rolls slowly past the building. The officer inside sips coffee, scanning the storefronts.

DAWN, DUSK, MAGIC HOUR, MORNING, EVENING

These are acceptable when the quality of light or the specific time matters to the scene. DAWN and DUSK suggest transitional, low-angle light. MAGIC HOUR (the period just after sunrise or before sunset) tells the DP that the scene needs warm golden light. Use these when the time affects the mood or logistics of the scene, not as variety for its own sake.

Avoid overly specific times like "3:47 PM" or "TUESDAY AFTERNOON" in scene headings. If the exact time matters to the story, convey it within the scene: a clock on the wall, a character checking their watch, or a chyron. The scene heading should stay simple.

Secondary Scene Headings

Secondary scene headings (also called mini-slugs) are abbreviated headings used to shift focus within a larger sequence without a full scene break. They omit the INT./EXT. prefix and time of day, and just name the area of focus. They are good for moving quickly through multiple spaces during a continuous sequence.

INT. HIGH SCHOOL - VARIOUS - DAY
The final bell RINGS. Students flood the hallways.
CAFETERIA
Trays CLATTER. A group of freshmen scramble for the last table by the window.
GYM
Coach Rivera drags a net of basketballs across the floor, shouting at stragglers.
PARKING LOT
Mia leans against a beat-up Honda, scrolling through her phone. She looks up as a yellow bus pulls away.

The primary scene heading establishes the general location and time. The secondary headings (CAFETERIA, GYM, PARKING LOT) move through specific areas within that location. This keeps the pacing brisk and avoids the visual weight of repeated full scene headings.

Mini-slugs also work well during phone conversations to cut between speakers, or during action sequences where the camera moves rapidly between different parts of the same location.

Use secondary scene headings when full headings would slow down a fast-paced sequence. But do not overuse them. If a scene in a new location has its own complete dramatic beat, it deserves a full scene heading with INT./EXT. and time of day.

Another common use of secondary headings is to direct attention to a specific detail within a scene. This is sometimes called a "detail slug" and functions like a subtle camera direction without using camera terminology.

INT. DETECTIVE'S OFFICE - DAY
Brennan studies the evidence board. Photos, maps, red string connecting pins. Something catches her eye.
THE BOARD
A photograph, half-hidden behind a newspaper clipping. The same face. Twenty years younger, but unmistakable.

Common Mistakes

Scene headings seem straightforward, but a few common errors trip up writers at every level. Avoiding these will keep your script looking polished.

Inconsistent Location Names

If you call a location "SARAH'S APARTMENT" in one scene heading, do not call it "SARAH'S PLACE" or "THE APARTMENT" in the next. Every time you change the name, a script breakdown tool (and a confused assistant director) will treat it as a different location. Pick one name and use it consistently throughout the entire screenplay.

Overly Specific Locations

Do not write "INT. THE FANCY ITALIAN RESTAURANT ON 5TH AND MAIN WHERE TONY PROPOSED TO MARIA - NIGHT." Scene headings are identifiers, not descriptions. Call it "INT. ITALIAN RESTAURANT - NIGHT" and let the action lines provide atmosphere.

Missing INT./EXT.

Every primary scene heading must begin with INT., EXT., or INT./EXT. Omitting this prefix is one of the most common formatting errors. Without it, the heading is technically a secondary scene heading, which carries different implications for scene numbering and production breakdowns.

Adding Description to the Scene Heading

The scene heading is not the place for description. Do not write "INT. LIVING ROOM, MESSY AND DARK - NIGHT." The heading identifies location and time, nothing more. Description goes in the action lines that follow.

INT. LIVING ROOM - NIGHT
Clothes draped over every surface. Pizza boxes stacked on the coffee table. The only light comes from a muted television.

Never include character names in scene headings (e.g., "INT. KITCHEN - JOHN ENTERS - NIGHT"). The scene heading identifies the location and time. Which characters are present, and what they are doing, belongs in the action lines.

Forgetting Time of Day

Every primary scene heading needs a time of day. Leaving it off creates ambiguity for the reader and causes real problems during production scheduling. Even if the time does not feel important to the story, the DP needs to know whether to set up day or night lighting. When in doubt, use DAY or NIGHT.

Screenwriting Fundamentals

Best Practices for Screenplay Writing

Screenwriting Fundamentals

Action Lines (Description)