Although Teaching Games for Understanding (TGfU) has gained ground, pedagogical models are sustainable only when situated in a comprehensive worldview and consistent epistemology. After considering the five values orientations offered by Jewett, Bain, and Ennis, the authors conclude that ecological integration offers a useful starting point in this regard, but taking this a step further, they offer a worldview that they call "ecological complexity," woven together from social constructivism, complexity, and ecological thinking. Since the authors argue that teachers who espouse this worldview focus on emergent learning, they have coined the term "emergent learning focused" (ELF) teacher to describe the pedagogical approaches that might result. These encourage the spontaneous play seen in the schoolyard, playground, or village green as opposed to work in the factory. ELF teachers encourage learners to develop holistically as they construct meaning, positioning themselves in the ecosphere of which they form an integral part. The authors apply ecological complexity to Inventing Games, in which learners invent and refine games within the TGfU classifications. They argue that as learners work together to invent and develop ownership of their games, they engage in a cognitive apprenticeship that prepares them for life in the wider community. Specifically, learners develop core social and emotional learning skills in a process that the authors have termed "situated ethics." As game play structures and constraints work in balance to produce disturbances, learners adapt and game play evolves. Learners learn to navigate these adaptations and evolutions by creating sustainable democratic processes. Teachers who operate from an ecological complexity worldview see all educational agents--learners, teachers, administrators, curriculum, school, community, and culture--as parts of a sustainable learning system. The authors conclude by offering the building blocks they believe might move this system closer to sustainability in games education.