The purpose of this study is to examine how community-based youth theater ensembles create conditions for youth to practice cultural agency and to develop a sense of themselves as valuable resources in a broader community development process. The researcher employed a qualitative methodology, using a critical and interpretive case study approach which enabled her to document and analyze three community-based youth theaters in New York City: Find Your Light, a playwriting/performance program for youth associated with the NYC shelter system; viBeStages, an all-girl youth ensemble (part of viBe Theater Experience or "viBe"); and Ifetayo Youth Ensemble (IYE), a multi-age ensemble for youth of African descent living in Flatbush and its surrounding neighborhoods (part of Ifetayo Cultural Arts Academy). All three programs are youth-based performing arts ensembles with a mission-driven focus on positive youth development and community building; they are long-term engagements, active in their communities for at least three years; and they are all part of arts organizations that value artistry as their principle means of impacting communities. All of the young artists involved in these programs participated in a sustained process of creating original performance pieces based on stories relevant to their lives and/or the lives of their communities. This dissertation examines how, through their playmaking processes, they began to identify, critique and experiment with commonly held beliefs about human agency and interaction, to activate and embellish the symbolic systems and repertoires that make up their communities, and to practice new ways of coming together. Through their use of artistic practices, the youth developed a sense of themselves as viable shapers of their communities and, in varying degrees, also used other aspects of culture (values, rituals, traditions, aspirations and the arts) to make meaning, contribute, and shape their cultural locations, offering new forms, symbols, structural models and imaginings.