Rosencrantz and Guildenstern are old school buddies of Hamlet's. They have been hired by the king to spy on Hamlet to find out why he is acting so peculiarly.
Rosencrantz and Guildenstern are Hamlet's childhood friends. Claudius sends them to spy on Hamlet.
They are friends of Hamlet's from school.
Hamlet.
He arranged for their deaths.
rosencrantz and guildenstern
Rosencrantz is (probably only was) a friend of Hamlet. Rosencrantz and Guildenstern (often considered one) spy on Hamlet the whole time for Claudius. They are constantly in between a plot that they have no idea about (Hamlet versus Claudius) and never learn of their real reason for their trip to Denmark. They probably had no idea that they were going to executed either.
True. Hamlet changed the king's orders to the English from "Kill Hamlet" to "Kill Rosencrantz and Guildenstern." He didn't have to do that; he could have changed the orders to "Give Hamlet some flowers".
Guildenstern and Rosencrantz
because he is dum
In Act III Scene 2 Rosencrantz asks what is the cause of Hamlet's distemper and Hamlet says that he lacks advancement. Rosencrantz asks how that can be when he is named as heir apparent. Hamlet responds by referring to an old saying, "While the grass grows, the horse starveth." by which he means that the promise of a future benefit is no use when there is a present need. He then gets very angry indeed at Rosencrantz for trying to ensnare him with conversation.
They are. If they weren't, Hamlet wouldn't have sent them to their death. They had the opportunity to betray him when they were out of his sight. It seems the king didn't completely take them into his confidence, though, so perhaps their loyalty wasn't total.
He says it is a prison.