A successful romantic drama relies heavily on the structural concept of the "Barrier." In Romeo and Juliet , the barrier is the family feud; in Brokeback Mountain , it is societal homophobia; in The Notebook , it is class difference.
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Romantic drama differs from its lighter counterpart, the romantic comedy, in one fundamental aspect: the presence of genuine, often insurmountable conflict. While comedies rely on misunderstandings that are inevitably resolved before the credits roll, dramas often pivot on external forces (war, class, illness) or internal flaws (fear, pride, timing) that threaten to keep the lovers apart.