Dramatic irony occurs when the audience possesses an insight which at least one of the characters lacks. In act 5, scene 2, the audience is aware that Claudius plans to use the fencing match between Hamlet and Laertes as an opportunity to finally rid himself of his nephew. The audience then witnesses Claudius asking for wine and dropping a "pearl" into Hamlet's cup. Hamlet isn't aware that Claudius has poisoned his wine, yet he dismisses the offer of a drink until he finishes his round.

Not realizing her husband's plans, Gertrude sees the cup—which the audience realizes is poisoned—and lifts it, offering a toast to Hamlet's good "fortune" in this bout.

This is a moment of dramatic irony. Not realizing that she holds a cup of poison, Gertrude drinks the wine, which quickly kills her.

It's also a moment of verbal irony. Toasting Hamlet's "fortune" is an ironic word choice; in fact, this duel is not fortunate at all for Hamlet. It has been designed to kill him, and though the poisoned wine won't be his end, a poisoned sword will.

A moment of situational irony occurs a few lines later. Laertes fights with a sword which has a tip laced in poison, designed to kill Hamlet. In a scuffle, the two drop and grab their partner's sword. Hamlet ends up with the sword which has unknowingly been designed to kill him and wounds Laertes. In the end, Laertes is killed by his own plans and with his own sword. The irony of this is not lost on him, as he reflects,

Why, as a woodcock to mine own springe, Osric. I am
justly killed with mine own treachery (5.2.327–328).

Claudius thinks he’s finally solved the problem of what to do about his errant nephew/stepson. He’s going to send him to England with his old school chums Rosencrantz and Guildenstern in tow. Once there, Rosencrantz and Guildenstern are to hand a letter to the king that will instruct him to have Hamlet killed.

But Hamlet’s no fool. During what’s intended to be his last sea voyage, he gets wind of Claudius’s dastardly plans and subtly changes the letter addressed to the King of England so that Rosencrantz and Guildenstern will be the ones who end up being killed. It’s a very clever, if somewhat chilling ploy. It’s also a paradigm example of situational irony in that Claudius’s actions have had the exact opposite effect of what he originally intended.

An example of verbal irony, where someone says something but means the opposite, comes in act 5, scene 1, the gravediggers’ scene. One of the gravediggers sarcastically comments in relation to the death of Ophelia that nobles are given more privileges to sin than other Christians. The gravedigger believes that Ophelia has committed suicide, which was widely regarded as a sin in those days:

And the more pity that great folk should have countenance in this world to drown or hang themselves more than their even Christian (5.1.25–27).

This is an example of verbal irony, as the gravedigger appears to be expressing sympathy over the supposedly unfair treatment of nobles. In in actual fact, he’s showing resentment towards what he sees as the special treatment they receive when it comes to being buried in hallowed ground despite having committed the sin of suicide.

Irony is commonly understood to be a moment when one thing is said, but another thing is meant. This most common form of irony is known as verbal irony and often recognized as sarcasm. However, in literature, we see irony presented in several forms. The most common form of irony we see Act 5 is situational as well as verbal irony. Situational irony is seen when an action takes place that is the complete opposite of what is expected.

One example of situational irony can be seen in Act 5, Scene 2 when Hamlet explains to Horatio how he managed to escape the trap that was set for him in England. While at sea, Hamlet found the letter the king had sent Rosencrantz and Guildenstern to England with ordering Hamlet's death upon their arrival. Instead, Hamlet wrote a new letter commissioning the deaths of Rosencrantz and Guildenstern and sealed it with his royal seal. This is a fine example of situational irony, especially from the perspective of the king, who expected Hamlet to never return from England. Another way in which this is an example of situational irony is that both Rosencrantz and Guildenstern were very close friends of Hamlet in school. Therefore, ironically, they accepted a commission from the king ordering his death, and, therefore, equally ironically, Hamlet ordered their deaths instead. The situational irony is seen in the double act of betrayal, as Hamlet points out himself in the lines:

Why, man, they did make love to this employment!
They are not near my conscience; their defeat
Does by their own insinuation grow. (V.2.61-63)

An instance of verbal irony can be seen in the gravedigger scene, Act 5, Scene 1. As the gravediggers are digging the grave for Ophelia, they question the fact that she is being given a "Christian burial." They comment on the fact the coroner has ruled that Ophelia accidentally drowned herself. However, the gravediggers actually believe that she had committed suicide. Any person guilty of suicide would not be given a Christian burial because suicide is one of the gravest of sins. The two gravediggers agree that, ironically, if Ophelia had not been a gentlewoman, she would have been pronounced as having willfully drowned herself and would not have been given a Christian burial. One gravedigger sarcastically comments that the nobility are given more privileges to sin than other Christians, as we see in his lines:

And the more pity that great folk should have countenance in this world to drown or hang themselves more than their even Christian. (V.i.25-27)

Since the gravedigger is sarcastically commenting on the unfair treatment of the noble class, we see that this is a perfect example of verbal irony. In addition, the fact that Ophelia is being given a Christian burial can also be recognized as situational irony because, just as the gravediggers point out, the situation is the exact opposite of what would be expected, since Ophelia did indeed drown herself.