A screenwriter or scriptwriter or scenarist is a writer who practices the craft of screenwriting, writing screenplays on which mass media such as films, television programs, comics or video games are based.
Screenwriting is a freelance profession. No education is required to become a professional screenwriter, just good storytelling abilities and imagination. Screenwriters are not hired employees, they are contracted freelancers. Most, if not all, screenwriters start their careers writing on speculation (spec), meaning they write without being hired or paid for it. When such a script is sold, it is called a spec script. What separates a professional screenwriter from an amateur screenwriter is that professional screenwriters are usually represented by a talent agency. Also, professional screenwriters do not work for free often, an amateur will often work for free and are considered writers "in training". Spec scripts are usually penned by unknown professional screenwriters and amateur screenwriters. There are a legion of would-be screenwriters who attempt to enter the film industry but it often takes years of trial-and-error, failure, and gritty persistence to achieve success.
Screenwriting in the film industry 
Every screenplay and teleplay begins with an idea, and screenwriters use those ideas to write scripts, with the intention of selling them and having them produced. The majority of the time, a film project gets initiated by a screenwriter and because they initiated the project, the writing assignment exclusively becomes his or hers. These are referred to as "exclusive" assignments or "pitched" assignments. Screenwriters who often pitch new projects, whether original or an adaptation, often do not have to worry about competing for assignments and are often more successful. When word is put out about a project a film studio, production company, or producer wants done, these are referred to as "open" assignments. Open assignments are more competitive. In situations where screenwriters are competing for an open assignment, more established writers will usually win these assignments. A screenwriter can also be approached and personally offered a writing assignment.
Script doctoring 
Many screenwriters also work as full or part-time "script doctors", attempting to better a script to suit the desires of a director or studio. 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. In fact, some writers make very profitable careers out of being the ninth or tenth writer to work on a piece; in many cases, working on projects that never see exposure to an audience of any size. Script doctoring companies, also known as script consultancies, are also often used by directors, production companies and individual screenwriters. These usually do not offer full re-writes, but are used when a production company or an individual requires feedback on whether or not a script is marketable, how it can be improved, and whether or not it holds any potential for development. Many up and coming screenwriters also "ghost write" projects and allow more established screenwriters to take public credit for the project.
Development process of a project 
After a screenwriter finishes a project, he or she pairs with an industry-based representative, such as a producer, director, literary agent, entertainment lawyer, or an entertainment executive. These partnerships will often pitch their project to investors or others in a position to further a project. Once the script is sold the writer only has the rights that were agreed with the purchaser. A screenwriter becomes credible once their work is recognized, giving the writer the opportunity to earn a higher income. As more films are produced independently (outside the studio system), many up-and-coming screenwriters are turning to pitch fests, screenplay contests and independent development services to gain access to established and credible independent producers. Many development executives are now working independently in order to incubate their own pet projects.
Production involvement 
Screenwriters are rarely involved in the development of a film. Sometimes they come on as advisors, or if they are established, as a producer. Some screenwriters also direct. Although many scripts are sold each year, many do not make it into production because the amount of scripts that are purchased every year outnumber the amount of professional directors that are working in the film and TV industry. When a screenwriter finishes a project and sells it to a film studio, production company, TV network, or producer, he or she often has to continue networking, mainly with directors or executives, and push to have their projects "chosen" and turned into films or TV shows. If interest in a script begins to fade, a project can go dead.
Video game writing 
Video game writing is also considered to be a form of screenwriting. Some film and television writers also work in this industry.
Most professional screenwriters in the U.S. are unionized and are represented by organizations such as the Writers Guild of America. Although membership in the WGA is recommended, it is not required of a screenwriter to join. The WGA is the final arbiter on awarding writing credit for projects under its jurisdiction. The WGA also looks upon and verifies film copyright materials.
See also 
- Screenwriter's salary
- Script (comics)
- WGA screenwriting credit system
- List of screenwriting software
- First look deal
- Television crew
- Film crew
- Ferguson, Brooks (17). "Creativity and integrity: Marketing the "in development" screenplay". Psychology and Marketing 26 (5): 428. doi:10.1002/mar.20281.