1. What is the purpose of the opening scene between Roderigo and Iago?

Othello begins in the city of Venice, at night; Roderigo is having a discussion with Iago, who is bitter about being passed up for a military post. Roderigo is a Venetian who lusts after Desdemona, and thus a tool in Iago's plots. Iago promises Roderigo that he shall have Desdemona's love in return for his help; Roderigo actually receives nothing but a disgraced death following his attempt on Cassio's life.