In act 2 scene 3 the play hamlet planned unfolded and Claudius guilt was proven. The act begins with Hamlet eagerly telling the players how to act to get the exact effect he wanted. Horatio enters the scene and Hamlet tells him how much he admires his qualities of self control. Hamlet then informs Horatio about the ghost of his father, and what information he gave him. He continued to explain how Claudius killed his father, and that ghost is asking for him to kill Claudius. Hamlet, still unsure about the ghost's intentions, tells Horatio his plan regarding the play and asks him to keep watch on Claudius. With Horatio confirming that he will keep his eye on the king for any awkward red flags, Hamlet starts the play.
As the play is starting Hamlet warns Horatio that he may act strangely as to confuse the king to his true intentions. A "dumbshow short silent version of the play starts showing the basic story, then the long extended fully developed version commences. The actors sure enough, act out the reality of what has happened. The murderer who kills the king turns out to be a family member. And Hamlet didn't forget to include the fact that the murderer ends up marrying the queen. At this point Claudius obviously affected by the play as he shouts for the lights on. Claudius storms out of the play, and the audience after him until only Hamlet and Horatio are left. They both pretty much come to the conclusion that indeed the king was guilty. During the play itself Hamlet would comment on the play while on the side making obscene comments to Ophelia.