"Othello" is one of William Shakespeare's most acclaimed tragedies. The story of a Moorish general (Othello) and the soldier (Iago) who plots to usurp him, the play features a small cast of characters who are manipulated and pitted against each other as part of Iago's deceitful plan. Two of the key characters are Cassio, Othello's loyal captain, and Roderigo, a man who is love with Othello's wife, Desdemona. Over the course of the play, both are lured into the complex love plot engineered by Iago, one of Shakespeare's best-written villains.
Cassio is described as Othello's "honourable lieutenant," and he is given this rank over Iago. The appointment, undeserved in Iago's eyes, justifies the villain's cruel revenge against him:
"One Michael Cassio, a Florentine… / That never set a squadron in the field / Nor the division of a battle knows."
(Iago, Act I Scene 1)
We know that Cassio is of good standing due to Desdemona's passionate defense of him. However, Othello is easily turned against him by Iago.
In Act II, Cassio foolishly allows himself to be encouraged to go for a drink when he has already acknowledged it to be the wrong thing to do. “Come lieutenant. I have a stoup of wine," Iago says (Act II Scene 3). "I'll do't but it dislikes me," Cassio replies. Once the captain becomes drunk, he is drawn into a brawl and attacks Montano, a former Cypriot official, badly wounding him. The attack is an embarrassment to Othello, who is forced to act quickly to appease the Cypriot officials. The Moorish general sacks Cassio on the spot:
"Cassio I love thee, but never more be officer of mine."
(Othello, Act II Scene 3)
Othello is justified in this, as one of his men has injured an ally; nevertheless, the scene demonstrates Othello's impulsivity and his righteousness.
In his desperation, Cassio falls into Iago's trap once more as he implores Desdemona to help him win his job back. His office is the most important thing to him, so much so that he neglects his relationship with Bianca while he is trying to get it back.
At the end of the play, Cassio is injured but redeemed. His name is cleared by Emilia and as Othello is stripped of his duties, we are told that Cassio now rules in Cyprus. As the new leader, he is given the responsibility of dealing with Othello's fate:
"To you Lord Governor, / Remains the censure of this hellish villain. / The time, the place, the torture O enforce it!"
(Lodovico, Act V Scene 2)
As a result, the audience is left to ponder whether Cassio will be cruel to Othello or forgiving.
Roderigo is Iago's dupe, his fool. In love with Desdemona and prepared to do anything to get her, Roderigo is easily manipulated by the evil Iago. Roderigo does not feel any loyalty towards Othello, who he believes has stolen his love from him.
It is Roderigo, under the guidance of Iago, who goads Cassio into the fight that gets him dismissed from the army. Roderigo escapes from the scene undetected. Iago tricks him into giving him money to convince Desdemona to be with him and then encourages him to kill Cassio.
In Act IV, Roderigo finally gets wise to Iago's manipulation of him, declaring that "Everyday thou daff'st me with some device" (Act IV Scene II). Nevertheless, he is again convinced by the villain to follow through with the plan to kill Cassio, despite his misgiving. "I have no great devotion to the deed," Roderigo says. "And yet he hath given me satisfying reasons. / 'Tis but a man gone. Forth, my sword: he dies" (Act V Scene 1).
In the end, Roderigo is stabbed his only "friend," Iago, who does not want him to reveal his secret plot. However, Roderigo finally outsmarts him by quickly writing a letter which he places in his pocket, pointing to Iago's involvement in the plot and his guilt. Although he ultimately dies, he is in some part redeemed by his letters:
"Now here's another discontented paper / Found in his pocket too. And this it seems / Roderigo meant to have sent this damned villain, / But that, belike, Iago in the interim / Came in and satisfied him." (Lodovico, Act V Scene 2)