John Proctor is the protagonist of the play. Once he enters the play, the real plot begins. Up to that point, the play’s exposition has introduced the town, some of the people in the town and the situation that will drive the plot: the accusations of witchcraft. Without John, the play would be a historical retelling of a terrible time in American history. His arrival makes the stakes of the play more specific, because John has a real dilemma: he wants to free his wife and his friends (and, eventually, himself) from false accusations of witchcraft, but he is asked to give up his dignity, honor and good name to do so. While the audience sympathizes with John, we also recognize that he’s a flawed protagonist. His flaw of lust led him to commit the adultery that makes him vulnerable to Abigail’s manipulations.
John represents the central struggle of the play: whether to confess and falsely accuse his neighbors, or to stand up for what he knows is right but face death in doing so. Because John is uniquely aware that the girls, lead by Abigail, are lying, and because he knows what Abigail is trying to achieve, his conflict is especially profound. Most other people in Salem must have at least wondered if there was some truth to the accusations of witchcraft, but John knows for sure that the girls are faking everything. His decision not to falsely confess resolves his conflict and ends the play. He changes from a man still naïve enough to gently flirt with Abigail at the beginning of the play to a man strong enough to give his own life to protect his name.