What is a scene heading in a screenplay?

A scene heading, or slugline, starts every new scene and tells the reader where and when it takes place. It is written in capitals in three parts: INT. or EXT. for inside or outside, the location, and the time of day, for example INT. LIGHTHOUSE - NIGHT.

The three parts

INT. or EXT. Interior or exterior. Use INT./EXT. when a scene moves between the two, such as a conversation in a moving car.
Location: as short and specific as possible. LIGHTHOUSE LAMP ROOM is better than A ROOM AT THE TOP OF THE OLD LIGHTHOUSE.
Time of day: usually DAY or NIGHT. You can also use CONTINUOUS when one scene flows straight into the next, or MOMENTS LATER or LATER.

Examples

EXT. HARBOUR WALL - NIGHT
INT. LIGHTHOUSE - CONTINUOUS
INT./EXT. FISHING BOAT - DAWN

Why they matter so much

Scene headings are what a production team uses to plan the shoot. Every unique location and time of day is grouped together for scheduling, so being consistent matters: if a place is MAGGIE'S KITCHEN once, don't call it KITCHEN later.

Common mistakes

Writing camera directions in the heading.
Changing the name of a location halfway through the script.
Starting a new heading for every small move inside the same space; a sub-heading or simply action is often enough.

Scene numbers

Scene numbers only go beside the headings once a script heads into production. Read when to add scene numbers.

Tip: in True-Script you can say "scene one, interior, lighthouse, night" and it writes INT. LIGHTHOUSE - NIGHT for you.

When do you need a new scene heading?

Start a new scene heading whenever the location changes or time jumps. If two characters walk from the kitchen into the hall, that is two scenes, because a film crew would treat them as two set-ups, possibly on different days. Even a few seconds of time passing in the same room can justify LATER, which tells the reader there has been a cut.

Secondary headings

When you move around inside a location you have already established, you can use a shorter secondary heading instead of repeating the whole slugline. After INT. FARMHOUSE - NIGHT you might simply write KITCHEN and later UPSTAIRS HALLWAY. This keeps the read fast while still telling the crew exactly where each moment happens.

Special cases

Flashbacks: add it to the heading, for example INT. SCHOOL HALL - DAY (FLASHBACK), and mark the return with BACK TO PRESENT or a normal heading.
Dreams and fantasies: treat them like flashbacks, with (DREAM) in the heading, so nobody is confused about what is real.
Montages and series of shots: use MONTAGE - MARA SEARCHES THE TOWN followed by short lettered or dashed lines, then END MONTAGE.
Phone calls between two places: use INTERCUT after establishing both locations, so you don't need a new heading every time the conversation crosses over.

Why scene headings matter to a production

Scene headings are not only for readers. Production teams break a script down by its headings: every unique location becomes a line in the schedule, and DAY or NIGHT decides lighting, crew hours and costs. A vague heading such as INT. HOUSE - DAY used for five different houses causes real problems when the first assistant director tries to schedule the shoot. Clear, consistent headings make your script cheaper and easier to make, which producers notice.

Keep location names consistent

Once you have called a place MARA'S FLAT, don't later call it MARA'S APARTMENT or THE FLAT. Screenwriting software, scheduling tools and the people reading your script all treat different names as different places. As you type a scene heading, True-Script's SmartType suggests locations you have already used, which keeps names consistent without you having to remember them.

Common questions

What does INT. and EXT. mean in a screenplay?

INT. means interior, a scene set indoors, and EXT. means exterior, a scene set outdoors. INT./EXT. is used when a scene moves between the two.

What does CONTINUOUS mean in a scene heading?

CONTINUOUS replaces the time of day when a scene follows straight on from the previous one with no time passing, for example a character walking from one room into the next.

Can a scene heading say DUSK or DAWN?

Yes. DAY and NIGHT are the most common, but DAWN, DUSK, MORNING and EVENING are fine when the light matters to the story. Use them only when the crew needs to know.

Should scene headings be bold?

Traditionally they are plain capitals. Some writers make them bold to help readers, which is acceptable in a spec script, but keep it consistent through the whole draft.