This Element presents an integrated account of psychodrama theory, practice, and research. It begins by exploring psychodrama's psychosocial roots and emphasizes Jacob Levy Moreno's pioneering work. Core concepts such as spontaneity, creativity, adaptability, encounter, act-hunger, action insight, and act fulfillment are discussed in detail. This is followed by an overview of psychodrama practice, including session structure, core techniques, and a positive psychodrama intervention program. Five research designs for outcome studies are presented, along with key issues such as bias assessment, treatment fidelity, treatment differentiation, feasibility, and acceptability in psychodrama research. Change process research is reviewed in light of the latest evidence and methods, highlighting eleven therapeutic change factors in psychodrama and discussing concepts such as moderation, mediation, and mechanisms of change. The final section addresses future directions, including nonverbal synchrony and physiological and neurobiological pathways in psychodrama research. This title is also available as Open Access on Cambridge Core.