While location-based games (LBGs) have been around for some time, only few of them have succeeded in attracting a larger number of players. One reason is the difficulty of suitable embedding of game concepts in an environment. In order to reach players from different places, LBG concepts need to be relocalized in a way which preserves the particular attractiveness of a game. What are criteria for high-quality (re-)localization? While the problem has been recognized in the literature, a systematic derivation of computational criteria is missing. In this chapter, we propose three novel criteria of game localization: playability, breakability, and authenticity. They are based on consistency and similarity measures in a 3-tier model of game localization, understood as a mapping of game actions and narratives into environmental affordances. We illustrate the use of the criteria in terms of a simple conquer game with two different narratives and two different environmental embeddings, as well as with an existing multi-player geogame.