Games live and die by their game mechanics. Engaging mechanics compensate for shortcomings in aesthetics, musical score, or level design, but nothing can make up for lackluster mechanics. This is especially the case for games for learning, which place additional constraints on the design of learning mechanics-specifically designed to foster learning, and assessment mechanics-specifically designed to measure learning outcomes. These mechanics can be inspired by game mechanics from successful commercial triple-A titles. We will describe our approach to designing games using these custom mechanics and present demonstrations from our library of related learning and assessment mechanics and their foundations.