Computer games started to be integrated in the learning process in order to bridge the gap between the new learner generation and the traditional learning process. However, today´s game-based e-learning environments do not provide different types of adaptation, with learners receiving mostly 'one size fits all” educational games despite the existing differences between them in terms of learner knowledge, motivation, etc. In this context, game-based e-learning can lead to demotivated learners. Therefore, there is a need for adaptation strategies. In order to make adaptation possible, real-time assessment of the game-play process as well as of the learning process is needed. Since learner motivation plays an important role in both the learning and the gaming process, and can easily change, new techniques for automated assessment of learner motivation are needed. This chapter presents current trends in game-based e-learning assessment in general focusing on the assessment of learner motivation in particular. Methods for gathering information on player/learner motivation are also presented. Information on learner motivation can be gathered (1) through dialog-based interaction, (2) through game-play-based interaction and/or (3) through additional equipment. This chapter also proposes four generic metrics for the measurement and analysis of motivation in game-based e-learning based on metrics that were used in e-learning. Each metric is presented and its usage and interpretation in gaming-based e-learning are discussed.