Throughout the play we see that Hamlet is indecisive and is afriad to take his own initiative, and is also a coward unable to act in critical situations. Following are the instances which prove this-
1. Hamlet gets a chance to kill Claudius in the chapel but instead he waits for another opportunity. We know that he wanted to avenge his father's deeath. So, if he truly wanted this, why does he keep on waiting, he could have used this opportunity to accomplish his task. He seems to be a confused person.
2. When Hamlet does kill Claudius, he is already wounded. It was his sheer luck that he himself was alive to kill him. If Laertes would have killed Hamlet in the duel as planned , Hamlet would not have been alive to kill Claudius. So, we can say that it was just Hamlet's chance which he seized.
Therefore, we can say that Hamlet is unable to create his own opportunites to kill Claudius, and is an indecisive character who called for his own termination. This indecisive trait seemed to be his biggest weakness, if he would have killed Claudius earlier , Hamlet himself would have been alive. We can also see that his indecisiveness got his entire family killed.
Hamlet constantly prolongs his decision to kill Claudius. He ponders again and again when to kill him.