Slavson and Moreno, pioneers of group psychotherapy, used activities as a primary method of change in their group work (Scheidlinger, 1995). Gillis & Bonney (1989) noted that if adventurebased activities were known during Moreno's heyday, he would probably be an adventure therapist as well as a psychodramatist. While the activity base for group work was generally abandoned for many years for the extensive use of "talk therapies," it has been "rediscovered" by art, music, wilderness, recreation, and other experientially based group therapies. The purpose of this chapter is to introduce the concepts of adventure therapy and provide readers with a rationale for the use of adventure experiences in group therapy.Gillis & Thomsen (1996) presented a global view of adventure therapy, placing it within the larger field of experiential therapies. In this view, adventure therapy is an active and experiential approach to group psychotherapy, utilizing an activity base (e.g., cooperative group games, ropes courses, outdoor pursuits or wilderness expeditions) and employing real and/or perceived risk (physical and psychological) as clinically significant agents to bring about desired change. Clients make meaning through insights that are expressed verbally, nonverbally, or unconsciously and lead to behavioral change. This is done from both verbal and nonverbal introductions prior to the experience as well as discussions following the experience (e.g., debriefings).Advanced techniques of adventure therapists include the use of metaphor, where the reality of the adventure experience is linked with the clients' issues. The use of metaphor is rooted in the psychotherapy work of Milton Erickson (Haley, 1973). Bacon (1983) and Gass (1993) advanced the use of metaphors in the presentation of therapeutic adventure experiences. Most of the therapeutic interventions used by adventure therapists are grounded not only in Erickson's work but also in the experiential approaches of Moreno (Blatner & Blatner, 1988), Perls (1969), Satir (1972), and Whitaker (Whitaker & Keith, 1981. Thus, many of the origins of adventure therapy can be traced to the stress-challenge experiences associated with taking groups into wilderness environments for recreational purposes (Bacon & Kimball, 1989) and the activities associated with team building through the use of challenge course experiences (Rohnke, 1989;Schoel, Prouty, & Radcliffe, 1988).