Characters in a play have many functions, however character presentation is ultimately dependent on the drama’s style and genre and cannot be considered separately. For example, in a farce and many kinds of satire, we do not expect realistic characters. Often they are quite stereotypical, to be recognized quickly for their type. Everything depends on the purpose of the drama suggested through its style.
If the play is of a realistic or naturalistic style, the most obvious function of the character is to represent particular people who are important to the story.
However, characters are also important tools for the writer in other ways. Characters can be carriers of the plays themes, embodiments of the ideas the writer is trying to convey.
Characters, particularly main characters, follow an arc in the story, which means that they develop or change over the course of the play. In a sense they are on a trajectory and we as audience sense that trajectory and want to follow them on it. In fact, it is the character’s pathway – their journey – that usually most interests us and involves us in the drama.
Of course a character’s journey is not always positive or beneficial to themselves or others; we are not talking about personal development here, but a dramatic experience. Shakespeare’s plays are full of characters whose journeys end in destruction for themselves and others. Hamlet is one example that immediately springs to mind. By the end of that play (spoiler alert!) the stage is littered in corpses, including Hamlet himself.
In realistic drama understanding the psychology of characters – what drives or motivates them – is an essential ingredient. We want to know why they do the things they do and what consequences arise from their particular personalities. A character’s psychology is therefore a source of dramatic conflict and action, with an individual’s inner conflict manifesting as outer conflict usually involving other characters who have “issues” of their own. Again Hamlet – procrastinator and angry young man – is a good example of inner conflict becoming outer conflict with disastrous consequences for many.
Some aspects of realistic characters you might want to consider as drivers and/or sources of conflict are: gender, age, physical qualities or disabilities, ethnicity, class, education or lack thereof, employment (current and past), health/sickness, financial situation, sexuality, obsessions, compulsions, fantasies and other psychological preoccupations. The list is not definitive, but covers many aspects worth thinking about. Many of the above considerations, as they apply to a particular character, will reveal, not only the psychology of the character, but also aid the actor in realizing the character in speech and movement.
When writing a realistic play it is important to know the back story of your characters – where they came from and why they are in their current situation and “condition”. You may not use the back story in your play, but it does help you have confidence in the reality of your characters and can be a source of new ideas and direction, especially if your characters are not “fleshing” out adequately or you hit a writing block.