In this article, we were interested in how young people learn to play games within a tactical games model (TGM) approach (Griffin, Oslin, & Mitchell, 1997) in terms of the physical-perceptual and social-interactive dimensions of situativity. Kirk and MacPhail's (2002) development of the Bunker-Thorpe TGfU model was used, to conceptualize the nature of situated learning in the context of learning to play an invasion game as part of a school physical education program. An entire class of 29 Year-5 students (ages 9-10 years) participated in a 12-lesson unit on an invasion game, involving two 40-min lessons per week for 6 weeks. Written narrative descriptions of videotaped game play formed the primary data source for the principal analysis of learning progression. We examined the physical-perceptual and social-interactive dimensions of situated learning (Kirk, Brooker, & Braiuka, 2000) to explore the complex ways that students learn skills. Findings demonstrate that for players who are in the early stages of learning a ball game, two elementary, or fundamental, skills of invasion game play-throwing and catching a ball-are complex, relational, and interdependent. © 2008 Human Kinetics, Inc.