A screenplay is composed of distinct elements, each with a specific purpose, format, and placement on the page. Understanding these elements is essential for writing a script that professionals can read, produce, and shoot from.
The Core Elements
Scene Heading (Slug Line)
The scene heading opens every new scene. It tells the reader three things: whether we are inside or outside, where we are, and when.
Format: ALL CAPS, flush left.
INT. HOSPITAL ROOM - NIGHT
EXT. PARKING LOT - CONTINUOUS
INT./EXT. CAR (MOVING) - DAY
- INT. = interior (indoors)
- EXT. = exterior (outdoors)
- INT./EXT. = both (inside a car by a window, doorway scenes)
- Location in caps after the period
- Time after the final dash: DAY, NIGHT, DAWN, DUSK, CONTINUOUS, LATER, MOMENTS LATER
Production departments rely on scene headings for scheduling. INT vs EXT determines lighting needs. DAY vs NIGHT affects the shooting schedule. Location names feed the breakdown.
Action (Description)
Action describes what we see and hear. It is the narrative backbone of the screenplay.
Format: Flush left, full margin width, present tense.
The hallway is empty except for a single flickering fluorescent light.
Sarah rounds the corner, stops. Her breath catches. At the far end,
a figure stands perfectly still.
Rules:
- Present tense only
- Visual and auditory information only — no internal thoughts
- First character introduction in CAPS with age: SARAH (32)
- Significant sounds in CAPS: A GUNSHOT. The door SLAMS.
- Keep paragraphs to 4 lines maximum
- White space is your friend — short paragraphs read faster
Character Name
The character name appears above every block of dialogue, identifying the speaker.
Format: Centered, ALL CAPS, approximately 3.7 inches from left margin.
SARAH
Extensions appear in parentheses after the name:
- (V.O.) — voice over (narrator, phone voice we hear, internal monologue)
- (O.S.) — off screen (character is in the scene but not visible)
- (CONT''D) — continued (dialogue interrupted by action, same speaker resumes)
Dialogue
The words a character speaks.
Format: Indented, approximately 2.5 inches from left, 3.5 inches wide.
SARAH
I didn''t come here to apologize.
I came here to tell you I''m done.
- No quotation marks
- Natural speech patterns — fragments, interruptions, incomplete thoughts
- Keep speeches short — long monologues are rare in produced films
Parenthetical
A brief acting or delivery note within a dialogue block.
Format: Below the character name, above the dialogue, in parentheses.
SARAH
(barely audible)
I knew.
Use sparingly. Parentheticals are for essential clarification only:
- Direction that contradicts the obvious read: (smiling) on a sad line
- Technical need: (into phone), (in Spanish), (sotto voce)
- Never for emotion: (angrily), (sadly) — trust your actors
Transition
Instructions for how one scene moves to the next.
Format: Right-aligned, ALL CAPS, followed by a colon.
CUT TO:
DISSOLVE TO:
SMASH CUT TO:
Modern screenplays rarely use transitions. CUT TO: is implied between every scene. Only use transitions for dramatic effect (SMASH CUT TO: for jarring contrast).
Additional Elements
Montage
A series of brief images showing passage of time or parallel action.
Intercut
Alternating between two locations, typically for phone conversations.
Title Card / Chyron
On-screen text: dates, locations, translations.
Dual Dialogue
Two characters speaking simultaneously, formatted side by side.
Shot (Rare)
Specific camera direction within action. Used extremely sparingly in spec scripts:
ANGLE ON the letter in Sarah''s hand.
Most screenwriters avoid shot directions — that is the director''s territory.
Format every screenplay element automatically in Seikan — scene headings, action, dialogue, parentheticals, and transitions styled to industry standards as you type. Free to start.