By the end of the tragedy, Hamlet has caused the deaths of Polonius, Laertes, Claudius, and Rosencrantz and Guildenstern, two acquaintances of his from childhood.
He is also indirectly involved in the deaths of his love Ophelia (drowning) and of his mother Gertrude (mistakenly poisoned by Claudius).
One night, his father's ghost appears to him and tells him that Claudius murdered him in order to usurp the throne, and commands his son to avenge his death.
Ophelia greets him, and offers to return his remembrances (tokens of his love interest), upon which Hamlet questions her honesty and tells her to "get thee to a nunnery" (a suggestion of either erotic criticism of hypersexuality, or of escape from the Danish succession crisis that will become bloody.)
When Claudius leaves the on stage "audience" deeply upset, Hamlet knows that the ghost was telling the truth.
Claudius, now fearing for his life, sends Hamlet to England, accompanied (and closely watched) by Rosencrantz and Guildenstern.
Prior to embarking for England, Hamlet hides Polonius' body, ultimately revealing its location to the King.
Laertes informs the king that he will further poison the tip of his sword so that a mere scratch would mean certain death.
In the Elsinore churchyard, two "clowns", typically represented as gravediggers, enter to prepare Ophelia's grave.
In his final moments, Hamlet names Prince Fortinbras of Norway as the probable heir to the throne.
Horatio attempts to kill himself with the same poisoned wine, but is stopped by Hamlet, so he will be the only one left alive to give a full account of the story.
Perhaps the most straightforward view sees Hamlet as seeking truth in order to be certain that he is justified in carrying out the revenge called for by a ghost that claims to be the spirit of his father.
The 1948 film with Laurence Olivier in the title role is introduced by a voice-over: "This is the tragedy of a man who could not make up his mind."
In this view, his efforts to satisfy himself on Claudius' guilt and his failure to act when he can are evidence of this unwillingness, and Hamlet berates himself for his inability to carry out his task.
The Protestant Reformation had generated debate about the existence of purgatory (where King Hamlet claims he currently resides).
Hamlet says that he would much rather take a stab at the murderer while he is frolicking in the "incestuous sheets", or gambling and drinking, so he could be sure of his going straight to hell.
Ernest Jones, following the work of Sigmund Freud, held that Hamlet suffered from the Oedipus complex.
He said in his essay "The Oedipus-Complex as an Explanation of Hamlet's Mystery: A Study in Motive": Harold Bloom did a "Shakespearean Criticism" of Freud's work in response.
Rosencrantz and Guildenstern tend to find the stalled ambitions of a courtier in their former schoolmate's behaviour, whereas Claudius seems to be concerned with Hamlet's motivation only so far as it reveals the degree to which his nephew is a potential threat.
And the First Gravedigger seems to think that Prince Hamlet, like that "whoreson mad fellow" Yorick, is simply insane without any need for explanation.
Several critics, including Stephen Booth and William Empson have further investigated the analogous relationship between Hamlet, the play, and its audience.
Given his great popularity (mentioned by Claudius), this would raise the question of why it was not he, rather than his uncle, who was elected to succeed to the throne upon the death of King Hamlet.
The line about the length of the Gravedigger's career does not appear in the First Quarto of Hamlet; in that text Yorick is said to have been in the ground only twelve years.
After going with them into a town and seeing the cruelty of Richard, Hamlet flees into the woods, where he is forced to face the ghost of his father.