There are many instances in Hamlet when we can see that William Shakespear belived in karma. We can see this in most of the charactors, more in some than in others. And it is the idea of what you do comes back to you. But, it seemes to only be your bad actions. We have direct conformation of karma from a few charators. One is Laertes, he is angered with Hamlet and plots to kill him with Claudius. He just so happens to have bought a verry potent potion while he was in france. He and Hamlet were to have a fencing match with a poisioned raiper, used by Laertes. One scrach can kill a man and no medicine can help them when Laertes is on the floor dieing he gives a verry important line. "As a woodcock to mine own springe" This is support of karma because he is saying like he was caught in his own trap like a bird caught in its own springe. This is like haveing a boomarang you dont know is a boomarang and you throw it hopeing to hit something and it comes right back to you when you least expect it. He continues saying " I am justly killed with mine own treachery" That is direct proof of karma. this is saying th We also see an instanceat he is with his own treachery of trying to kill Hamlet he was killed.
Annother instance of karma is with Hamlet and Ophelia. The at the begining of the scene when Ophelia spurns Hamlet by giving him his letters back. When he gazes upon Ophelia he says " Nymph, in thy orisons be all my sins remembered" he is esentualy saying alas there is my true love, and he is remembering all the time they have had together. Then she spurns him by giving him his letters back and that upsets him this is stage one of his love leaving him. When Hamlet accadentaly kills Polonius, Ophelia goes truely mad. And in her madness accadentaly kills herself by falling into the lake and drowning. the greatest thing you can take from someone is their life. Next would be to take someones lover from them. So in the act of killing Polonius he lost his lover so again karma is playing a role in Hamlet.