Advances in game-based learning and educational data mining enable novel methods of formative assessment that can reveal implicit understandings that students may demonstrate in games but may not express formally on a test. This chapter explores a framework of bridging in game-based learning classes, where teachers leverage and build upon students’ game-based implicit learning experiences to support science classroom learning. Bridging was studied with two physics learning games in about 30 high-school classes per game. Results from both studies show that students in bridging classes performed better on external post-tests, when accounting for pre-test scores, than in classes that only played the game or did not play the game at all. These findings suggest the teachers’ role is critical in game-based learning classes. Effective bridging includes providing teachers with common game examples along with actionable discussion points or activities to connect game-based learning with classroom content.