Hamlet:
* Polonius: Hamlet, in his madness, kills Polonius believing him to be Claudius.
* Rosencrantz and Guildenstern: Hamlet orchestrates their deaths by sending them to their execution in England.
* Claudius: Hamlet kills Claudius in a duel, ultimately fulfilling his desire for revenge.
* Laertes: Hamlet inadvertently kills Laertes in the duel, after Laertes' sword is poisoned by Claudius.
Claudius:
* King Hamlet: Claudius murders his brother, King Hamlet, to seize the throne and marry his widow, Gertrude.
* Polonius: Claudius orders Polonius' death after he overhears Hamlet's plans to expose Claudius.
* Laertes: Claudius provides Laertes a poisoned sword and encourages him to duel Hamlet, knowing it will lead to his death.
* Gertrude: Claudius poisons a cup of wine intended for Hamlet, but Gertrude drinks it accidentally, leading to her death.
Other characters:
* Laertes: He instigates the duel with Hamlet, driven by revenge for his father's death and his own injuries. His desire for vengeance leads to his own death and Hamlet's.
* Fortinbras: Though not directly responsible for any deaths, his ambition to claim the throne of Denmark contributes to the volatile atmosphere of the play.
Ultimately, each character's actions and decisions contribute to the tragic ending. While Hamlet might be considered the central catalyst for the deaths, everyone bears a share of the blame.