Shakespeare incorporated the theme of madness to serve a motive for Hamlet in order to deceive others. Hamlet planned everything from what he was doing to what he was going to do. Hamlet did in fact pretend to be mad, just so he could follow through on his plan to avenge his father’s death. He acted like he was mad because he did not want to directly kill Claudius, because he wanted to make him suffer. Hamlet also knew that he could not tell anyone that Claudius has murdered his father or that he had seen the ghost of his father because no one would believe him.
Hamlet himself says, "That I essentially am not in madness, but mad in craft." He thought about everything he was doing, and everything he was going to do. Hamlet did in fact act like he was mad, just so he could follow through on his plan to avenge his father's death. Hamlet acted like he was mad because he did not want to outright kill Claudius, because he would probably go to heaven, and Hamlet wanted to make him suffer like Claudius had made his father suffer. Hamlet also knew that he could not go around telling people that Claudius killed his father just because a ghost told him so.
Although Ophelia does go insane and ultimately commits suicide, the central lunacy of the play revolves around Hamlet himself. Hamlet's plan to act mad is completely unexplained. It is safe to assume that he is pretending to be mad so he can get away with saying and doing things that would not ordinarily be tolerated. Also, if people think that he was crazy, they would not pay any attention to him in his plot to kill Claudius and avenge his father's death. This plan backfires though, because his family and friends bend over backwards to find the cause of his madness.
Though his planned maneuver to murder his uncle Claudius, the contrast between his feigned madness and Ophelia’s true madness, and his ability change behavior around different characters that possess his trust, Hamlet’s true, rational condition emerges from beneath his veil of insanity. Hamlet is not truly mad because he is merely using the guise if madness as part of his plan to murder Claudius. After the ghost of old King Hamlet relates the dreadful story of his demise to the young prince Hamlet realizes that his abhorrence of his uncle Claudius is wholly justified. To avenge his father’s murder, Hamlet valiantly uses his keen mind to devise a plan that will confuse Claudius and lure his uncle into a false sense of security. Hamlet decides the best method of deception to trick Claudius is to pretend that he suddenly becomes a raving lunatic.
He then comes up with a plan to have the actors put on a play that is similar to the Murder of King Hamlet. Hamlet assumes that if Claudius has a reaction towards the play, he is guilty. This soliloquy is important because it reveals that Hamlet believes that he is dull spirited, it also points out that Hamlet is frustrated at himself for not having killed Claudius yet. All Hamlet is thinking about for the duration of this soliloquy is Claudius, and how he killed King Hamlet. Toward the end, Hamlet comes up with an idea to know if Claudius is guilty.
There is much evidence in the play that Hamlet deliberately feigned fits of madness in order to confuse and disconcert the king and his attendants. His avowed intention to act "strange or odd" and to "put an antic disposition on" 1 (I. v. 170, 172) is not the only indication. The latter phrase, which is of doubtful interpretation, should be taken in its context and in connection with his other remarks that bear on the same question. To his old friend, Guildenstem, he intimates that "his uncle-father and aunt-mother are deceived," and that he is only "mad north-north-west." (II.
The ghost tells hamlet he needs to kill King Claudius but Hamlet is to busy consumed in all the problems he has, that he doesn’t act at the right time. He had many chances to do something about King Claudius but didn’t because he was too indecisive about it. For example: when the King is kneeling paying Hamlet has a chance to kill him but he doesn’t. He talks himself out of murdering him, and instead makes a play to see if he is guilty. Hamlet talks to the actors of the play and decides to make them act out his father’s murder.
The ghost informed Hamlet that he had been killed by Sir King Claudius and that Claudius was, in fact, Hamlet's uncle. From there, the ghost only asked for one thing and one thing only, and all the deceased king requested was revenge from his son. Taking in all this information, wanting to avenge his father's death, and wanting to do as his father asks causes Hamlet to do many crazy things, including pretending to have lost his sanity. This causes many deaths in the story during Hamlet's journey to revenge. One of which was Polonious, who was stabbed by Hamlet during Hamlets rant to his mother.
In scene vii, Claudius tells Laertes that Hamlet is responsible for Polonius’ death and they advise a plan to kill him without the suspicions of foul play. Laertes also plans to use a sharpened sword instead of a dull fencing blade. Laertes is known for his expertise with a sword. Then tragic hits again as Gertrude comes in with news of Ophelia’s death. Ophelia drowned in the river, which causes Laertes to flee the room, overcome with grief.
Hamlet has been instructed by the ghost of his late father to avenge his death by killing King Claudius. This is what brings mistrust and eavesdropping into the picture. Claudius has suspensions about Hamlet’s peculiar behavior, and has summoned his school chums, Guildenstern and Rosencrantz, to spy on him. Before they even start their expedition of eavesdropping, the King and Polonious have already made plans to hide being a wall hanging during Hamlet and Ophelia’s exchange of love gifts. King Claudius is determined to discover an alternative motive to Hamlet’s madness besides depression.