Shakespeare used many different character traits to compose full-bodied characters that we can still relate to today. These characters are similar to those that we would perhaps see in a current action movie in that they have the same traits as our villains and protagonists. Having been introduced to almost the full cast of the play in the first scene, we can clearly understand the intentions of most of the characters. Even though we cannot exactly see the aspirations of some characters in the story until later on, it is quite plainly laid out for the audience to see what kind of person each character is.
Commencing with Roderigo, we are introduced to this character in the very first lines of the play and undoubtedly the audience is immersed into his plot to steal Desdemona away from Othello. We learn that Roderigo has been paying Iago to help him woo Desdemona and direct her away from Othello but Iago tells Roderigo that it is too late and Othello has married Desdemona. Upon hearing this Roderigo begins to provoke Iago's hatred for Othello by backing up Iago every time he mentions of Cassio's promotion instead of his own. This particular scene which happens at the opening scene of the play is imperative in judging Roderigo. We can see he is persuasive and more importantly determined to win Desdemona's heart even after the discovery of her eloping. Even more peculiar than Roderigo's persuasiveness is Iago's, especially when used against Roderigo.
Iago is perhaps the character I trust the least in the character but perhaps the most exciting. He is the most manipulative, heinous villain who plans all of the sneaky plots and from the second scene of the book, appears to be the most persuasive and in control character. When we discover that Iago thinks Othello is sleeping with his wife, we can assume that Iago is even slightly not in the right mind or completely sane. It is Iago's plan to approach Brabantio in the middle of the night and tell him he has been robbed by thieves.