First of all, there are many more than four characteristics of traditional Greek tragedies: there are about ten. Hamlet can account for all as it is, after all, the nature of the play. For example, a ghost (of the late King of Denmark) is the one who reveals the need for revenge. Prince Hamlet himself is the person who takes it upon himself to do the act of attaining such revenge by murdering his uncle, his father's murderer. However, he hesitates to do so, another main part of the type of work, but does later, just before his own death, and everyone elses'.