Game User Research is an emerging field that ties together Human Computer Interaction, Game Development, and Experimental Psychology, specifically investigating the interaction between players and games. The community of Game User Research has been rapidly evolving for the past few years, extending and modifying existing methodologies used by the HCI community to the environment of digital games. In this workshop, we plan to investigate the different methodologies currently in practice within the field as well as their utilities and drawbacks in measuring game design issues or gaining insight about the players' experience. The outcome of the workshop will be a collection of lessons from the trenches and commonly used techniques published in a public online forum. This will extend the discussion of topics beyond the workshop, and serve as a platform for future work. The workshop will be the first of its kind at CHI, tying together HCI research and Game User Research.