This document discusses how online games can facilitate the development of 21st century skills. It notes that the modern workplace requires skills like problem-solving, teamwork, communication and managing self. While schools aim to teach these skills, much learning occurs informally through social play and collaboration. Online games provide opportunities for "collateral learning" of 21st century skills when played socially. Researchers have found games can help players manage information, thrive in diverse environments and adapt to changing conditions. The document envisions online games and virtual worlds being used in schools and lifelong learning to supplement formal curricula and foster skill development through communities of practice.