Games are powerful. People can spend a lot of time playing games. Games are also great motivators. People do things that don´t even like, if they feel like they are playing game. Gamififcation is the use of game mechanics to motivate people to do stuff they generally would not do. Playing can also be very good of your brain and give you useful skills. In this lecture we explore some of the elements of gamification and why you should don´t worry about playing computer games.