Before they enter practice, law students need to be able to work effectively in groups. This reality has been acknowledged by the universities and legal professional bodies. The Threshold Learning Outcomes (TLOs) for the Australian Law degree stipulate, for instance, that law students must acquire and be able to demonstrate skills in collaboration and communication. Meanwhile, a growing body of research is establishing the positive links between group work and a range of benefits, including achievement, critical thinking, problem-solving ability, creativity, wellbeing and satisfaction. Not only does group work enhance a student’s experience and individual performance, it also equips them with critical practice skills. Despite this, law students typically dislike and resist group work, which means they may not be achieving important professional competencies. Nevertheless, to force students into group learning would seem counterproductive. As we examine in this paper, students’ aversion to group work likely signals low intrinsic motivation – where intrinsic motivation means doing something because it is in itself enjoyable or optimally challenging; and where extrinsic motivation, by contrast, means doing something because it leads to or avoids a separate outcome. Making group work assessable as the primary way to induce student collaboration, or otherwise simply mandating it, means participation rests on external rewards and punishments. Extrinsic teaching approaches usually result in less effective learning. We argue in this paper that when designing group work, it is essential to consider and apply theories of learning motivation. This article asks the following: How can we increase the likelihood that law students positively engage in collaborative learning? To address this, the article draws on a theory of motivation, Self-Determination Theory (‘SDT’), to propose a framework and set of strategies for effective group-based learning in legal education. Pintrick and Schunk describe SDT as ‘one of the most comprehensive and empirically supported theories of motivation available today.’ It has been used in other legal educational areas, including curriculum design and assessment, and ethics and wellbeing. However, we consider it especially useful for group-based learning. The article adds to the small but growing legal education scholarship on teamwork, and makes distinct contributions in its motivational theory dimension, setting up an SDT framework designed to promote collaborative learning.