Full-length plays having a three-act format last for over two hours. By contrast, one-act plays are essentially short plays having a complete story. They are enacted against the backdrop of a single scene and may last for about thirty to sixty minutes. A budding playwright can get acquainted with the basics of play writing by learning to write a one-act play. The format and content of the play is largely determined by audience. So it helps to know the target audience in advance. A writer can keep some essential guidelines in mind to help him in creating appropriate format and content for a one-act play.
According to Aristotle dramas should have a unity of time, location and action. In conformity with these rules, most traditional plays have a central plot, the action of which unfolds in a single location having duration of less than a day. These unities of drama can be used effectively in writing one-act plays which are generally short and have no place for subplots or changes in scenes. The setting of a one-act play is usually restricted to a single scene. So care should be taken to generate the setting in such a way that the story line is made clear to the audience. One of the important elements in creating the setting is the use of lighting. Detailed notes should be included o the use of lighting to create the required setting. Ideally the setting should engage the five senses to increase the appeal to the audience. .
The subject of a one-act play should be such that it can be dealt with effectively in a short duration. A short story would work well combined with effective characterization and action. It would be good idea to research and read other one-act plays so that the new playwright has some solid examples to emulate. Plays differ in form and content and one can learn the different forms of construction, the type of setting used the number of characters, the time frame of the plot and so on.
One-act plays have lesser number of characters acting against a simple setting. In most cases the focus will be on the main character and his goals. Almost every scene of the play will feature the main character and his dilemmas. The best way to develop the characters is to outline a character sketch and then fill in the details. The characters should be life-like having a basic purpose in life. The problems and situation that they face in fulfilling their motives help in further shaping their character.
After the main task of writing a one-act play, it is time for testing it out. The best way would be to enact the play. Useful feedback can be taken from those connected with the various stages of the play. Additionally expert advice can be sought in the production of the play. Apart from a number of practice sessions, a dress rehearsal should be ideally done in the final practice before the real show. This would be a good opportunity to do away with any inanities found in the plot.