Games are a $60 billion global industry played by 97% of American teenagers and the average Facebook gamer is 39 years old. Research organizations argue games offer attributes for 21st century learning like systems thinking and problem solving. Games are being used by non-profits and agencies to further educational and social goals. G4C's methodology involves understanding the audience, context, desired impact, appropriate platform, financial sustainability, gameplay design, execution process, and evaluation metrics. Case studies demonstrate games in classrooms, developing countries, direct action games, mass collaboration, youth creation, and evaluation/brain research.