The concept of dramatic situation is important in dramaturgy and narratology. In the domain of story generation and interactive digital storytelling, this concept is particularly powerful in creating meaningful story variations from a single core model. Nevertheless, dramatic situations and the related notion of deep narrative structures have been overlooked in the domain of computational models of narrative. This article presents a computational model of dramatic situations. Designed with creative authors in mind, the model consists of a small set of building blocks that, when assembled with specific relations, create narrative structures. Some structures that are described are of particular interest from a dramatic point of view, for they embed a fundamental paradox. These structures are generalized and formalized to allow an exhaustive search and to establish an initial list of dramatic situations that share this property.