This chapter provides an overview and implementation guidelines of Just-in-Time Teaching (JiTT), an interactive engagement pedagogy used across disciplines and across the academy, now in its fourteenth year. The heart of JiTT pedagogy is Web-based pre-instruction assignments called warm-ups, with some colorful local variations, such as GeoBytes in a geology class. Students respond to the warm-up questions and go to class with genuine interest and desire to learn the answers. The pedagogy has proved effective in improving classroom climate and student motivation and in fostering deeper learning.