Vincentio, The Duke
The ruler of Vienna, he decides at the beginning of the play to pretend to leave town, and pass his power along to Angelo, a man who is very strict. The Duke stays in Vienna, disguised as a friar, to observe the goings-on. He is a man who knows that human nature is weak and can be corrupted, and accepts this to some extent. He knows that being a ruler requires that a person be fair and not punish people for their faults when they are faults that the ruler has too.
Angelo
The Duke's deputy, he comes to power suddenly and unexpectedly when the Duke leaves Vienna in his power. It seems to be some kind of test for the cold, seemingly perfect Angelo, who soon discovers that he too is capable of being tempted, and of falling to this temptation. Although he is aware that he should resist sin, he gives in with abandon.
Escalus
Another in government service to the Duke. Escalus pledges to uphold the law and support whomever leads Vienna, though he disagrees with Angelo's punishment of Claudio especially. He is a generally good man who seeks to support the state, while at the same time ensuring that the state acts fairly.
Claudio
A young gentleman who gets into trouble when he gets his fiancée, Juliet, pregnant before their wedding. Angelo imprisons him and sentences him to death; no one agrees that this is a just punishment for a very common crime in Vienna, and many seek to persuade Angelo to show mercy and reverse this judgment.
Lucio
Claudio's more dissolute friend, a man who likes debauchery and drinking and is not sorry for his sins. He knows that Angelo's attempt to crack down on the city and eliminate its vices will not work, for the simple reason that human nature is always prone to vice, and sin cannot be purged from people completely.
Isabella
Claudio's sister, she is in a convent at the beginning of the play. She tries to plead with Angelo for Claudio's life, but is far too proud, pious, and selfish to agree to his terms, even if it means saving her brother. She is a basically good person, but misguided; her idea that her virginity is worth more than her brother's life is ridiculous, as she could stand to learn a bit about reason and the outside world as well.
Juliet
Claudio's fiancée, whom he got pregnant. They are contracted to be married, and are very much in love; she laments that her would-be husband must be killed, as she would prefer to just marry him and bear the child. Although her and Claudio's crime was slight, she still admits fault, but wishes they could be together.
Mariana
Angelo's ex-fiancée, he broke his contract of marriage with her very abruptly when her dowry was lost. She is still desperately in love with him after several years, and consents to the Duke's plan to get Claudio free because it will also force Angelo to marry her after all.
Provost
A figure of justice in the jail, like Escalus, he is committed to following the law. However, he too sees that Claudio should not die for his crimes, and does his best to help Claudio secure justice.
Elbow
The constable, he is simple-minded to the point of being ridiculous every time he comes into the play and makes an accusation. Speaks in malapropisms and is a figure meant for the audience's enjoyment, rather than to advance the plot.
Froth
A foolish gentleman, he comes in handy during a comic relief scene since Elbow accuses him, somewhat humorously, of insulting Elbow's wife.
Pompey, the clown
He is a bawd, making his money off of assisting Mistress Overdone at her brothel. He is also a comic relief figure, but is drafted into execution duty for Claudio and Barnardine.
Abhorson
The executioner at the prison, he is rather dour and businesslike, which might be good considering his position.
Barnardine
A long-time prisoner, he is supposed to be executed along with Angelo. He is a lazy drunk, and does not repent of his crimes.
Friar Thomas, Friar Peter
Allow the Duke to disguise himself as a friar, and provide him general support in trying to free Claudio.
Mistress Overdone
Mistress of a brothel in Vienna, she is dissolute and debauched, but has taken care of Lucio's illegitimate son for some time.
Francesca
A nun of the convent that Isabella is in, she plays no part in the action because as a nun, she cannot leave the convent nor talk to men.
Two Gentlemen
Are generally debauched figures, jesting with Lucio about their venereal diseases and high regard for the whorehouse.
