Central among the wide range of hypnotic phenomena that are fascinating to both the researcher and the clinician are hypnotic dreams and hypnotic hallucinations. In fact, for many they are the most intriguing of the various experiential events that occur during hypnosis. The two hypnotic phenomena overlap in the kinds of underlying processes that they imply, are peculiarly cognitive in nature, and also relate meaningfully to other hypnotic phenomena considered in this book in terms of the quality of the experiences that are associated with them. Both have been described as constructions of imagination that may be transiently confused with reality (E. R. Hilgard, 1977) such that the hypnotized individual may come to believe that his or her dream or hallucination is actually occurring. Both phenomena also involve processes such as absorption and imagery (see Chapter 4) and implicate different modes of cognizing (see Chapter 3) that are employed by susceptible subjects to facilitate their experience.