Screenwriters or script writers are authors who write the screenplays from which films are made. Many of them also work as "script doctors," attempting to change scripts to suit directors or studios; for instance studio management may have a complaint that the motivations of the characters are unclear or that the dialogue is weak. Script-doctoring can be quite lucrative, especially for the better known writers; David Mamet and John Sayles, for instance, fund the movies they direct themselves, usually from their own screenplays, by writing and doctoring scripts for others.
Most professional screenwriters are unionizedized and are represented by organisations such as the Writers Guild of America.
Some notable screeenwriters: