Because he and King Claudius planned it...they put poison on the end of the sword so that when Laertes stabs Hamlet, Hamlet dies.
The motive also has to do with the fact that Laertes is avenging his father's (Polonius's) death, whom was killed by Hamlet.
He did it inadvertently; he did not know that Laertes' sword was envenomed; he only knew that it was unbated.
Hamlet didn't write any letters to Laertes--ah, you mean "Did Claudius read the letter Hamlet wrote to Claudius out loud to Laertes?" I confess that it is difficult to phrase this question so it is unambiguous. Yes, Claudius reads the letter he got from Hamlet out loud to Laertes and asks whether Laertes can explain it.
Hamlet stabbed him with the poisoned sword which Laertes had poisoned to kill Hamlet. He was, in Hamlet's phrase, "hoist with his own petard."
Laertes annoints his sword in order to poison Hamlet, however at somepoint in the match (after Laertes poisons Hamlet, but before Hamlet is killed by the poison), Laertes and Hamlet switch swords and Hamlet also poisons Laertes.
Laertes had planned to kill Hamlet by fencing with him with a real pointed sword, not a harmless one with a button on the end. He has also poisoned the end of the sword. The idea is that Laertes is a better swordsman and will be able to skewer Hamlet with the poisoned rapier. Unfortunately for him, Hamlet is actually the better swordsman. It looks like Laertes is never going to touch him within the context of a duel. Thus Laertes abandons the polite conventions of duelling, and with the line "Have at you now!" attacks Hamlet in earnest. This does enable him to wound Hamlet, but in the scramble Hamlet gets hold of the pointy rapier and fatally wounds Laertes as well. Some productions show Laertes actually stabbing Hamlet in the back, but the above is more consistent with the text.
Laertes is killed by the poisoned sword that he originally killed Hamlet with. After wounding Hamlet with the poisoned sword, the swords are switched and Hamlet wounds Laertes with the poisoned sword.
Laertes tries to kill Hamlet and is successful.
Claudius and Laertes plot to kill Hamlet.
Laertes is the son of Polonius and brother to Ophelia whom Hamlet loves. King Claudius poisons Laertes's sword with the intent to kill Hamlet in the tragedy play by Shakespeare titled Hamlet.
Hamlet didn't write any letters to Laertes--ah, you mean "Did Claudius read the letter Hamlet wrote to Claudius out loud to Laertes?" I confess that it is difficult to phrase this question so it is unambiguous. Yes, Claudius reads the letter he got from Hamlet out loud to Laertes and asks whether Laertes can explain it.
Laertes - Hamlet - was created in 1600.
Hamlet stabbed him with the poisoned sword which Laertes had poisoned to kill Hamlet. He was, in Hamlet's phrase, "hoist with his own petard."
Claudius knew. That's why he conspired with Laertes to kill Hamlet first.
Laertes annoints his sword in order to poison Hamlet, however at somepoint in the match (after Laertes poisons Hamlet, but before Hamlet is killed by the poison), Laertes and Hamlet switch swords and Hamlet also poisons Laertes.
Laertes poisons his on blade in order to kill Hamlet.
Poisoned sword
does* and it's a duel that was set up before by Laertes and Claudius to kill Hamlet. For Laertes because Claudius told him that Hamelt murdered his brother and for Claudius so Hamlet doesn't spill the secret that Claudius murdered Senior Hamlet.
This would be Laertes.