He has been working with the development of video game theory since the late 1990's. His publications include Half-Real on video game theory, and A Casual Revolution on how puzzle games, music games, and the Nintendo Wii brought video games to a new audience. He maintains the blog The Ludologist on "game research and other important things". His most recent book is The Art of Failure: An Essay on the Pain of playing Video Games. http://www.jesperjuul.net