Thread creep (sort of). I had an English Lit prof at the UW who disagreed with the usual interpretation that Hamlet was wimpy and indecisive. She pointed out that one of the questions Hamlet had to answer to his satisfaction was the nature of the ghost that appeared in the form of his father. At that time it was commonly believed that goblins, or even the Devil himself, could appear in whatever guise they wished, and deceive someone into doing something which would damn their souls to Hell. In Act I, scene 1, when the ghost first appears to Hamlet and wants him to follow it to where they can talk alone, Horatio warns him not to, for fear the ghost would assume "a pleasing shape" and lead him to the edge of the tower and lure him to fall to his death. Then the big question: Hamlet asks the ghost if it is "a spirit of health or a goblin damned?" That, she said, was the question Hamlet had to answer before he knew whether he should off Claudius. After all, he was grief-striken over the death of his father, and he was furious at the hasty marriage ("Within a month!") of his mother and his uncle. He would be vulnerable to the evil temptations of some demon in disguise, and he knew it.
Hamlet pokes around, trying to verify what the apparition told him. Did Claudius murder his father, or didn't he? The fortuitous appearance of the players gives him an opportunity to put Claudius to the test. Present a play about the way the ghost said the murder took place, and see how Claudius reacts.
Claudius loses it. Now Hamlet knows. The apparition was telling him the truth. It really is the ghost of his father. Immediately following the play, Hamlet could have killed him, but Claudius, in an agony of guilt, was praying. Hamlet wants Claudius to burn in Hell for what he did, and if he kills him while he's praying, he would go straight to heaven. So he awaits another opportunity.
Plot complications follow, preventing Hamlet from carrying out his revenge, but on his return to Denmark, he looks for a good opportunity to do the deed. After all, now he knows that Claudius is trying to kill him, too. The fencing match gives him a possible chance (he's confident that he can win against Laertes because, as he tells Horatio, he's been practicing daily). But Claudius and Laertes conspire, and they cobble the fencing match. As a result of this treachery, both Laertes and Gertrude wind up dead. And although Hamlet is dying from a scratch from Laertes' poisoned weapon, he picks up the poisoned sword ("The point, envenomed, too. Then, venom, do thy work!") and runs Claudius through with it. Wow! Bodies all over the stage.
Not indecision, the prof said. Hamlet had to play detective. The indecision thing was the interpretation of a famous eighteenth century actor (whose name I forget) who was copied by other actors.