Extension
In screenwriting, the Extension is an directional abbreviation used to tell the reader the state of an unseen character's dialog.
toc_collapse=0;Usage
There are three basic Extensions, O.S. (off-screen), O.C.(off-camera) and V.O.(voice-over)
O.S. and O.C. are basically interchangeable and are used as a way of focusing in on the reactions one particular character or characters to an unseen character.
V.O. is used as a narration that is unheard by everyone but the audience.
Format
All three Extensions are pecifically placed in parentheses to the right of the character name.
Examples
O.S.
Mary stands meekly against wall at the annual office Christmas party. She watches John approach. She looks away.
JOHN (O.S.) Pilates. It must be the pilates because I'll tell you, Mary, you look awesome.
Mary gives a blushing smile as she inadvertantly runs her hands over her hips.
MARY Is that the best you got?
O.C.
John stands confident with a dirty Martini in hand as Mary approaches. He shoots her a smoky glance.
MARY (O.C.) Well, John, I see you forgot to wear pants again.
John's confidence wanes to terror as his eyes roll down toward his nether regions.
V.O.
John stands confident with a dirty Martini in hand as Mary approaches. He shoots her a smoky glance. She approaches.
JOHN (V.O.) Mary's looking good. I only wish....oh, man, I forgot to wear my pants again.