Research on asynchronous online discussions has primarily focused on their efficacy in relation to learning outcomes. Rarely are there investigations on how the design of online learning activities or how discussions could be incorporated into student learning experience. We contend that successful online activities need careful and meticulous design. We are particularly interested in how the design of "rules" or protocols for group interactions contributes to the quality of student learning experience. This article reports a three-year study on designing and refining such rules for online discussions. Specifically, we studied how rules support or inhibit online discussions. Reported in the article are the processes and rationales for each refinement of the rules based on real interactions. We argue that existing learning management systems still fall short in supporting various learning activities afford- ed by these rules. Therefore, various tools are proposed based on our findings. These tools should be integrated into existing learning management systems such as Blackboard or Moodle. (Contains 1 table.)