There are many differences in understanding of what games are, as well as multiple approaches to the design process and challenges it poses. The golden recipe that would create a quality product simply doesn't exist. This particulary applies to games which serve as a media for transfering unique intagible experiences, and as such have to deal with complex issues regarding interactivity, game control and emotions that arise from it. A good design appears through an iterative process of re-examination, development and change. The most valuable insights come from the process of making a product and, with that, making mistakes. "To create, one must first destroy.", says the author of "The Art of Game Design". Performing changes does not necessarily include destruction of the structures that have already been built, but finding suitable and efficient ways of adjusting them, based on continuous research and new discoveries. Given that the product's purpose lies in the culture and environment of its targeted users, it is necessary to invest effort and resources into examining the ways players are interacting with the game, the rate of their success, difficulties presented and feelings that are being conveyed. For those reasons, and many more, tests are being introduced into the product development program. In case of a game, the process is called "playtesting" and its purpose is to understand the design, system, interactivity and gameplay, including the synthesis of the rules of play and feelings that arise from the act of playing. While different methodologies and practices do exist, choosing a suitable test method largerly depends on the environment in which the product is being made, as well as on the stage of its development. With aim to explore it, this paper provides an overview of practices from experts in the field, and also a detailed description of the research conducted in the early stages of desigining a game.