All characters in your play must have goals: things they want, need, and desire. Goals are necessary for creating conflict. When your protagonist and your antagonist’s goals are opposed to each other, that’s when you create conflict and tension, and the resulting outcome is the action that drives the play forward.
It’s very important to understand that there are two kinds of goals in a play: the concrete things that a character wants (their primary goals) and the abstract ideas that we often want to set as the goals for our characters to pursue (their secondary goals). In the world of play writing, there is a clear distinction between these two types of goals: the former is a catalyst for conflict and tension, and the latter is one that, by itself, can’t be directly depicted in a play because it relies on whether the character reaches his goal.
Let’s say that your protagonist starts out the play as a lonely man who realizes that he wants a lady in his life. To say that his character’s goal is to “find love” or “be happy” is not a goal that works well because it’s generic and intangible. It’s more accurate to say that your character wants to find a woman, woo her, marry her, and get a dog and move to a little house in the country where he will live happily ever after. These are concrete goals, because we can actually watch him do these things. My guess is that if you were to ask him what his goal in the play actually was, he wouldn’t say “love.” He’s more apt to say “I want to marry Margie.” And throughout the play, if he’s smooth enough and says and does the right things, he will get what he wants. The added bonus in this scenario is that by obtaining his primary goal (Margie), he’ll thereby realize his secondary goal (love).
Along these lines, a character’s primary goal doesn’t often change, or if it does, it might change once when a character has come to some sort of major or life-altering realization that gives him a new sense of purpose and resolve, redefining where he needs to go in his journey. If you decide to give a character a new goal, make sure that you have a good reason for doing so. But for the most part, characters tend to keep their eye on the one big prize that the play is dangling in front of them. While a character’s goals tend to remain static, the tactics, steps, and strategies the character employs to reach his goal might change depending on the circumstances the character finds himself in. These are the objectives, or the “mini goals” that a character needs to meet in order to gain the payoff (his primary goal) he’s working toward.
For example, if our protagonist’s (Let’s call him Sam.) goal is to marry Margie, he will have a series of smaller goals he needs to complete before he can do that. Let’s say that Sam meets Margie at a party and they hit it off, so he decides to send her flowers at work the next day. And Sam discovers a complication: Margie already has a boyfriend. Does Sam’s primary goal change? No, he still wants to marry Margie. But the steps he takes to win her over (i.e. the objectives he has to complete to reach his goal) will be very different for winning the affections of a single, unattached Margie than a Margie who is already in a relationship. And if he is successful in meeting his objectives, then not only does he get the girl, but he also gets love.
For this reason, it is important to distinguish between the primary goals you give your characters, which must be concrete, and the secondary, abstract goals that you ascribe them. In addition, it helps to keep your character focused on one major goal–the one thing that the play is about–but allow him to be creative in the objectives or the means by which he works to reach his goal. By keeping these concepts in mind, you will have a clearer idea of not only where your character needs to go, but also what he must do to get there.