Americans spend 90 percent of their time indoors, but rarely realize the complex systems involved in making their daily lives possible. In 2011, the federal General Services Administration launched the Sustainable Facilities Tool (SFTool) to help government agencies and the general public build, buy, and operate sustainably. Green the Building, an SFTool-hosted educational game, provides understandable and fun context to green building strategies that enlighten the novice and engage the expert. The game reaches beyond technical jargon and compliance standards, allowing users to discover actions they can take to improve sustainable building performance. It was intentionally developed using an innovative browser-based interface, rather than an app, to allow players to easily bounce between game play and the more than 150 “Learn more at SFTool.gov” links embedded throughout the game. GSA followed a phased approach in development, partnering from inception with subject matter experts, instructional designers, and game designers, then later with artists, programmers, testers, and education professionals. After defining rules of play for the turn-based, dynamic scoring game, the team developed an overarching narrative to engage players and encourage them to invite others to compete.