What Is a Slugline? Screenplay Slugline Explained

Slugline or scene heading? The same element, two trades

They are the same thing. If you search one term and find the other, nothing has been lost in translation.

Slugline is the older word, and it comes out of the printing trade. In newspaper composing rooms a slug was the short label set on a story — a few words that identified the copy so it could not be confused with anything else on the stone. Film and television borrowed it, and the slugline became the line that gives a scene its slug: its short working name.

Scene heading is the reader-side and software-side word. It describes the typographic job — the line that heads the scene — and it is the name Final Draft, WriterDuet and every other screenwriting program gives that element. Manuals written in the last twenty-five years tend to follow the software's vocabulary.

So use whichever fits the room. Say scene heading in a coverage note or a contest entry, and say slugline to a first assistant director, a script supervisor or a producer, and you will be understood instantly. What actually matters is the convention, not the label: one line, ALL CAPS, starting with INT. or EXT..

The three components, and nothing else

A slugline carries three pieces of information, in this order, separated by a space-hyphen-space:

INT. NORTH POINT LIGHTHOUSE - NIGHT

• INT. or EXT. — interior or exterior. The only part that is always abbreviated.
• Location — the specific place, in ALL CAPS. Name the room or the spot the scene plays in.
• Time of day — DAY, NIGHT, DAWN, DUSK, CONTINUOUS, LATER.

When a scene plays in a room inside a larger, named location, the larger location can be attached with a second hyphen or a comma:

INT. RAVENSWOOD HOUSE - KITCHEN - DAY
INT. RAVENSWOOD HOUSE, KITCHEN - DAY

Both forms appear in produced scripts; pick one and use it consistently. If the house has already been established, plain INT. KITCHEN - DAY is cleaner and shorter, and shorter is the point — a slugline that wraps onto a second line is a slugline doing too much work.

What a slugline is not

Three things get glued onto sluglines by writers who are still learning the form.

A shot

CLOSE ON, ANGLE ON and POV are shooting-script language. They belong in a shot list, not a spec. If a shot is genuinely load-bearing — if the scene only works because we see one particular thing — write it as an action line instead: Under the door: two shoes, one heel broken.

Scene description

The paragraph under the slug is scene description, and describing is its job. A slugline only names. EXT. BEACH - A PERFECT EVENING THAT SMELLS OF SALT is a mood wearing a slugline's clothes; EXT. BEACH - DUSK plus an action line does the work properly.

A transition

CUT TO: and DISSOLVE TO: are transitions. They sit at the right margin, after the action and before the next slugline — never inside it. Contemporary specs drop almost all of them, because a cut is the default and naming it adds nothing.

There is also a formatting implication here: because the slugline is a structural marker rather than prose, screenwriting software stores it as its own element type. That is why pasting an unformatted paragraph into a slugline and hoping the reader will read it as prose does not work — it will be read as a location and a time of day, and it will break the rhythm of the page.

How a slugline is used in production

The word survived because of what it does after the script is finished. The slugline is a database key.

• The breakdown. Each slugline is broken down into a strip: scene number, INT./EXT., set, day or night, page count in eighths, cast, extras, and any stunts, vehicles, animals or props flagged in the scene.
• The stripboard. Those strips are sorted into shooting order — everything at one location together, all day work before night work. The schedule is, quite literally, your sluglines rearranged.
• The call sheet. Scenes appear by number with a shortened slug beside them: SC. 24 — LIGHTHOUSE / NIGHT.
• The slate. The second assistant camera writes the scene number, the take and a short slug on the slate. The spoken announcement is just 'scene twenty-four, take one' — no one reads the punctuation aloud, and no one says the word interior on a busy set. On set, a slugline is spoken as a scene number.
• Continuity notes. The script supervisor logs every take against the scene number and slug, so a line of dialogue that changes on the day is traceable to one place in the script.

A working writer who keeps this in mind writes better sluglines without thinking about it. If the location name you chose would be ambiguous on a call sheet — three rooms in the same house, all called INT. HOUSE — production will have to disambiguate it for you, and you will not be in the room.

Slugline mistakes that actually cost you reads

1. Lower case. Sluglines are set in ALL CAPS without exception. Mixed case in the heading reads as a first draft.
2. No time of day. EXT. PARKING LOT tells a reader nothing about the light in the scene, and the first AD cannot schedule it.
3. Vague locations. INT. SOMEWHERE - NIGHT is a shrug. INT. BUS STATION LOCKER ROOM - NIGHT is a scene.
4. The impossible interior. INT. FOREST, INT. STREET, INT. HIGHWAY — none of these are enclosed. If a character is inside a structure in a forest, name the structure.
5. Repeating an unchanged slugline. Consecutive shots inside one scene do not get new sluglines. New location, new slugline; same location, keep going.
6. Scene numbers in a spec draft. Numbers belong to a production draft, where they sit in both margins and stay with the scene through revisions. In a script you are sending to a manager or a competition, they signal that you formatted the wrong kind of document.
7. Time of day that fights the scene. EXT. ROOFTOP - DAY followed by action about the skyline at night is a continuity problem, a lighting problem and, first of all, a reading problem.

One habit prevents most of these: read the slugline on its own, then read the scene. If the slugline answers where, inside or outside and when, and nothing else in the scene contradicts it, it is finished.

Where a slugline sits on the page

In standard US spec format, a slugline starts flush at the left action margin — 1.5 inches from the left edge of US Letter paper — with a blank line before and after it, set in uppercase Courier. It is never indented like dialogue and never centred. When the page breaks mid-scene, the slugline carries the scene number, or the words CONTINUED: and CONTINUED, so a reader can see at a glance that the scene is still running.

That left margin is shared with action lines, which is deliberate: sluglines and action are the two elements that describe the physical world of the scene, and the eye should be able to run down the left edge of the page to find them. Dialogue is what lives in the middle of the page, indented on both sides.

None of this is decoration. The whole format is calibrated so that one page of screenplay plays as roughly one minute of screen time, and any heading that swallows half a page throws off the only reliable runtime estimate a reader has.

Frequently asked questions

Continue reading

More in screenplay formatting

• What Is a Scene Heading? Format, Rules & Examples
• INT. vs EXT. in a Screenplay: When to Use Each
• What Does O.S. Mean in a Screenplay?
• What Does V.O. Mean in a Screenplay?
• How to Format Dialogue in a Screenplay
• How to Format a Phone Call in a Screenplay
• How to Format a Montage in a Screenplay
• How to Format a Flashback in a Screenplay
• Screenplay Margins and Font: The Industry Standard
• How Many Pages Should a Screenplay Be?
• Screenplay Formatting Examples: Every Element on One Page