When Shakespeare and other playwrights of the same period wrote in verse, they elevated the tone and form of the plays to convey a more poetic and sophisticated milieu. It is often said that one can tell which characters are of the noble classes and which are of the lower classes in Shakespeare's plays, because the former speak in verse and the latter speak in prose.
Curses and prophecies serve to emphasize the political impact of Richard's reign and the effect his actions will have upon the future of the kingdom. There is a sense that his reign is cursed by his own arrogance and impulsive actions. This speech by Gaunt indicates a sense of Richard's reign being cursed down the ages:
. . . Thy deathbed is no lesser than thy land,
Wherein thou liest in reputation sick;
. . . A thousand flatterers sit within thy crown,
Whose compass is no bigger then thy head . . .
O, had thy grandsire with a prophet’s eye
Seen how his son’s son should destroy his sons,
From forth thy reach he would have laid thy shame,
Deposing thee before thou wert possess’d. . . .(II.i.93-107)
The speaker suggests Richard's flaws are connected to his choices and actions, as opposed to being passed down through his ancestral line or encouraged by family tradition.