What Is a Slugline in a Screenplay?

A slugline is another name for a scene heading — the single capitalized line that begins every scene and tells the reader where the scene takes place, inside or outside (INT vs EXT), and when. If you can read sluglines alone and always know where you are, the script is well-sluglined.

The Master Scene Heading

The standard slugline has three parts:

INT. or EXT. — LOCATION — TIME OF DAY

Real examples:

INT. COFFEE SHOP — DAY
EXT. GOLDEN GATE BRIDGE — DAWN
INT. HOSPITAL — HALLWAY — NIGHT

• INT./EXT. — interior or exterior (see INT vs EXT)
• Location — short and specific: MARA'S APARTMENT, not A SMALL BUT WELL-KEPT APARTMENT
• Time of day — usually just DAY or NIGHT; use DAWN, DUSK, CONTINUOUS, LATER, or MOMENTS LATER only when it matters

Every full scene gets exactly one master heading. A new master heading = a new scene.

Secondary Sluglines

Inside a scene, you can shift focus to a new space or detail without starting a new scene. These secondary sluglines are flush-left, ALL CAPS, and stand alone on their line:

INT. MARA'S APARTMENT — NIGHT

Mara flips the deadbolt. Freezes.

HALLWAY

A shadow slides under the bathroom door.

BACK TO LIVING ROOM

Mara exhales and crosses to the window.

Secondary sluglines work because the master heading already established the larger location (MARA'S APARTMENT). Don't jump between buildings with them — that needs a new master heading.

INSERT and CLOSE ON

For brief cutaways to objects or details:

INSERT — THE ENVELOPE

Her name, typed. No return address.

BACK TO SCENE

CLOSE ON — HER HANDS

Steady. Too steady.

BACK TO SCENE

INSERT, CLOSE ON (or CLOSEUP ON), and BACK TO SCENE are conventional in specs. Use them when the detail is a plot beat — the poisoned glass, the trembling trigger finger — not for decoration.

Special Sluglines

These aren't locations, but they occupy the slugline position and behave like headings:

• MONTAGE — TRAINING DAY — a sequence of compressed shots (full guide)
• SERIES OF SHOTS — THE CITY WAKES — like a montage, but linked by theme rather than a single through-line
• BEGIN FLASHBACK / END FLASHBACK or a heading suffixed (FLASHBACK) (full guide)
• INTERCUT — PHONE CALL — bouncing between two locations (phone call formatting)
• SUPER: / TITLE: — text superimposed on screen: SUPER: "Moscow, 1986."

Slugline Best Practices

1. Consistent naming — INT. JAKE'S APARTMENT must stay JAKE'S APARTMENT for all 90 pages
2. One line only — if it wraps, the location name is too long
3. Dash separators — use a space-dash-space (—), not periods
4. Minimum viable time-of-day — DAY/NIGHT by default; resist THE WITCHING HOUR
5. Don't direct from the slugline — camera angles don't belong in a spec heading

Frequently Asked Questions

Is a slugline the same as a scene heading?

Yes — "slugline" (or "slug line") is the informal/industry term; "scene heading" is the formal element name. Secondary sluglines (sub-locations, INSERT) are also called "mini-slugs."

Do secondary sluglines need a time of day?

No. They inherit the time and place of the master heading above them.

Can a slugline be two lines?

It can wrap in software, but a professional slugline fits on one line. Shorten the location instead.

What comes right after a slugline?

An action line (also called description) — what we see and hear in the scene.

Related Pages

• INT vs EXT — the first word of every slugline
• Scene Headings — the craft-side guide
• How to Write a Montage — special sluglines in action
• Fountain Syntax — how sluglines are detected in plain text