" Wikipedia has good game mechanics. Player action has direct and clear results: edits appear instantly on the site, giving users a powerful sense of control over the environment. This instant impact creates optimism and a strong sense of self-efficacy. It features unlimited work opportunities, of escalating difficulty. As the Wikipedians describe it, “Players can take on quests (WikiProjects, efforts to organize many articles into a single, larger article), fight boss-level battles (featured articles that are held to higher standards than ordinary articles), and enter battle arenas (interventions against article vandalism).” It also has a personal feedback system that helps Wikipedians feel like they are improving and making personal progress as they contribute. “Players can accumulate experience points (edit count), allowing them to advance to higher levels (lists of top-ranking Wikipedians by number of edits). "
― Jane McGonigal , Reality is Broken: Why Games Make Us Better and How They Can Change the World