Like the feature film, a short narrative film tells a story. Beyond this, the similarities fade. Short screenplays (sometimes called tenners) can be 1 to 40 pages long, but are generally between 5 to 30 pages.
In a short film, there's no time to develop an elaborate plot structure. Most writers choose to focus on one plot or idea. Subplots can take too long to develop, and can detract from the central theme of the script. Plot is often less important than visual style, mood, and character. Some short filmmakers make films based on situation, not story. Generally, these films are ironic, as they show characters in unusual situations that are resolved through some final "twist."
Story evolves when a character has a need, must overcome obstacles, and change in an attempt to reach a goal. A narrative film is much more compelling when based on this kind of dramatic situation. However, in the short film, the character's need has to be identified very early on. The obstacles have to arise almost immediately, and the path to resolution has to be well-plotted and well-paced. Many experts believe a successful short film is one that leaves the viewer with a single strong emotional impression. Therefore, the focus for the short script writer should be on emotional impact.
Write for a small number of central characters - ideally two, with a maximum of three, and make them interesting. These main characters do not necessarily have to speak or even be human.
Before writing the script, consider outlining the plot, or free-writing as a way to better understand the message within the story. The clearer the theme appears, the easier it will be to transfer onto the page.
Basic questions to consider when writing a short screenplay:
The basic message for making a short script more attractive to filmmakers is to keep all the filmmaking elements as simple as possible. Locations should be contained and controllable, but unusual or interesting, and ideally, use only one. Set the story in present day, during the day. Avoid children and animals. Create exterior scenes that could be shot indoors if necessary. Keep dialogue in exterior scenes to a minimum. Use minimal special effects, car and street scenes, public scenes, and any scenes that involve crowds.
Short scripts are not always easier to write, sometimes they're almost as difficult as writing features. It's often a challenge to say more with less, and the compressed format leaves no room for adjustments. Shorts are limited in characters, less fleshed-out, and have no subplots. However...
Short films are more fluid than features. Some stories lend themselves to the short format. A writer's own short stories can be great source material for short scripts. For those who prefer writing shorts, and want to be paid, try sitcoms, at about 24 pages long.
A short film is a calling card, a showpiece for a writer's work. A great or very good feature script can open industry doors, but a great short can sometimes provide faster results. Some industry execs will spend ten minutes watching a short film, where they may be less willing to devote a couple of hours to reading a screenplay.
Shorts can be a process for new screenwriters to learn about film structure, technique, and characters. Consider short scripts - they may be the best introduction to the basic craft of screenwriting, and present the opportunity to create a buzz in the industry.