First of all, Shakespeare uses Fortinbras as a contrast to Hamlet. Fortinbras and Hamlet are both seeking revenge for the death of their fathers and are faced with making decisions about how to take their revenge. Fortinbras" father was killed by Hamlet Sr. and therefore Fortinbras goes to war over a worthless piece of territory just to uphold the honour of his father. "The imminent death .go to their graves like beds .which is not tomb enough and continent to hide the slain." (Hamlet, IV, iv, 59-64). Family honour is just as important to Fortinbras as it is to Hamlet. A key difference between them is that Fortinbras did not procrastinate, like Hamlet and lived, while Hamlet procrastinated and not only died but caused the death of other innocent people. Fortinbras has the capability to make a plan, and act it out even with the possibilities of unexpected obstacles arising. This proves that Fortinbras is more eager to prove his courage and uphold his family honour than Hamlet is. He could and did what he wanted, while Hamlet thought of different things but could not take action. Fortinbras had no difficulty in slaying innocent people in an attempt to uphold honour. However, Hamlet had a lot of difficulties in slaying the guilty. Hamlet contrasts his capabilities to act to those of Fortinbras. "When honour's at the stake, how stand I then trick of fame." (IV, iv, 55-60) Fortinbras" ability to act and his leadership weakens Hamlet in the eyes of the reader. Hamlet wants justice to be served, along with honour, all while seeking revenge. Fortinbras is able to avenge his father and more importantly regain his father's honour in doing so. However, Hamlet waits till the end of the play to ensure that honour is regained and that justice is served. .
Secondly, Claudius is used by Shakespeare as a foil for Hamlet. Claudius and Hamlet are similar is some regards but have more evident differences. They both kill a king in the play; however, they had both done so for different reasons.