All of the characters listed here are static characters (meaning they do not undergo any sort of change from the beginning of the text to the end) with the exception of John Proctor and perhaps Reverend Hale. John Proctor's character at the beginning of the story was a man who carried the weight of his guilt upon his shoulders for his previous indiscretions (havind had an affair with their house servant, Abigail). He angered at his wife's continued mistrust over the course of the seven months since she learned of his affair. However, his anger was really founded in his own guilt and understanding of the pain he caused his wife Elizabeth. By the end of the play he finally is able to let go of this guilt by doing the right thing, that being to refuse to give up his name to save his life in light of the fact that others, more innocent and virtuous than he, are dying because they refuse to lie. As he says in Act IV, "Because I sign myself to lies.... I am not worth the dust on the feet of them that hang" He realizes his mistakes and cannot continue to live his life under a pretense. He must be honest with everyone, even if it means dying. Even his wife Elizabeth recognizes this change when she says "He have his goodness now. God forbid I should take it" (Act IV).
Reverend Hale may be a round character because he initially believes Abigail and signed many death warrants. By Act III he reailzes the truth and does all he can to stop the hangings.