Without a strategy in place, online discussions in asynchronous courses rarely rise above the level of information sharing. As a result, it is important to design discussion strategies that push students further in their interactions with both the content and each other. In this case study, the role-play strategy was examined to determine whether it fosters critical thinking and student engagement. Student discussion transcripts were examined from an online, self-paced human biology course using both Garrison et al.'s four-phase model of cognitive presence and Gunawardena et al.'s five-stage model of knowledge construction to look for evidence of higher-order thinking. Furthermore, the transcripts were examined qualitatively for phrasing that signified evidence of student engagement. The findings indicate that the role-play instructional strategy, when used in online discussions, does support student engagement and critical thinking. This strategy places students in authentic, real-world contexts and enables them to explore different perspectives while engaging with the content to discover new knowledge and construct new meaning. The research presented here also supports evidence that written reflection should be incorporated when employing the role-play strategy. Based on the insights from this study, the researchers have developed a framework for students to achieve deeper, more engaging online discussions. This framework is called the "Framework for Student Engagement and Critical Thinking in Online Discussions."