Stanislav Grof is renowned as a pioneer in the world of psychedelic psychotherapy and research.  During more than four decades of exploration in the field of consciousness studies, Grof has accumulated data on some six thousand psychedelic sessions, having conducted more than four thousand of these sessions himself.  As Grof puts it in his introduction, “This book …explores the extraordinary philosophical, metaphysical, and spiritual insights that have emerged in the course of this work” (pp. 2-3).  He goes on to assert that these insights are “in radical conflict with the most fundamental assumptions of materialistic science concerning consciousness, human nature, and the nature of reality” (p. 3). Grof speculates that Jung's archetypal realm of the "collective unconscious" can be directly experienced only in "holotropic" states.   The events and beings apprehended in this "mythic realm" unfold in a space and a time different from that at the ordinary material level. As such, they have a quality that evokes episodes often described as "sacred" or "numinous" (p. 69). This is a "large and important domain of existence for which materialistic science has failed to provide reasonable and convincing explanations" (p. 268). Grof's pioneering investigation of this realm provides a rich legacy for future explorers.
The Cosmic Game is an excellent introduction to Grof’s work and the conclusions to which this work has led him.  Just as Memories, Dreams and Reflections provides a biographical context helpful in understanding the genesis of many of Jung’s most important ideas, The Cosmic Game is generously leavened with fascinating – and often touching – anecdotes from Grof’s, and his patients’ personal experience – drawing on both psychedelic sessions and day to day experience.  These anecdotes are invaluable not only in providing background to Grof’s research, but also in helping the reader to understand why the study of consciousness is so meaningful, both to Grof and to the rest of us.
By placing his intellectual conclusions within a spiritual, historical, and personal framework, Grof has written a book that will be especially helpful to those who may be new to the field of consciousness studies, or whose experiences with psychedelics may have led to difficulties or doubts concerning their previous understanding of reality.  His work provides a succinct and very well-informed critique of mainstream scientific thought without resorting to naïve new age thinking (e.g. you create your own universe and are totally responsible for all that happens therein).  He offers fresh insights into the nature of “reality” vs. “virtual reality” (p. 76), the inescapability of evil in the universe (p. 132), the values and varieties of unitive experience (p. 79), and summarizes his original thoughts on the links between birth trauma and aggression (p. 204), which he had previously discussed in The Holotropic Mind, and has termed “perinatal matrices.”.
Along with The Holotropic Mind, The Cosmic Game offers several fascinating avenues for future research.  For example, the link between birth trauma and aggression, mentioned above, could be explored.  An investigator could check birth records of people who commit aggressive acts (clearly defined beforehand) to see if they had had more difficult (i.e. traumatic) births than people who do not exhibit such behavior.
The Cosmic Game is carefully written and edited – we noted very few errors: moral rather than morale on page 168, and, arguably, referring to shamanism as a religion on page 255 (we would contend that shamanism is a spiritual technology and practice that predates organized religion by tens of thousands of years).
Although The Cosmic Game is essentially an introduction to and summation of Grof’s unique perspective on human existence, we would not hesitate to use the word “classic” to describe it.  We look forward to a future work in which Grof goes further in presenting his own paradigm, which may someday help to dislodge the current one, which The Cosmic Game so clearly and thoroughly exposes as being defunct.