The overall research focus in this interlinked project concerns the affordances of game based learning for (pre-)vocational track students in the domain of mathematics. Specific research questions concern the effects of game characteristics on students? motivation, learning processes, and acquired knowledge. In a set of research projects that share common elements (the game-based learning environment, tests, and process measures) variations in the game that concern learner control, competency, level of uncertainty, situatedness, reflective prompts, and curiosity are investigated. To help explain effects, dedicated process measures are applied, including (neuro)physiological techniques. After a set of studies within each project, results will be grouped and implemented in (a) final design(s) of the learning game and comparisons to a direct instructive methods will be made. The interlinked programme will indicate concrete conditions under which positive learning effects are established. It will result in design guidelines for effective game-based learning.