Introduction: Advance Care Planning (ACP) is a part of comprehensive palliative care but there are challeges for its implementation. In Thailand, undergraduate medical curriculum also has not implemented palliative care and ACP as a core teaching topic for the medical students yet. Life Unlocking Card Game is an end-of-life conversation card game that aims to bridge this gap. Objective: To assess second year medical students' attitude of death by using Life Unlocking Card Game and its effectiveness to teach about death and dying. Methods: Non-equivalent quasi-experimental design with convenience sampling method. All (48) of second year medical students participated in an end-of-life conversation game (8 games in total with one facilitator within each group). After that, each group formed an after-game focus group interview. Seven students also joined individual semi-structured interviews. We used content analysis approach along with investigator triangulation and methodological triangulation methods for the qualitative analysis. Results: Participants (n = 48) were second-year preclinical medical students. 26 of them were male (54.2%), 22 were female (45.8%), with the mean age of 20 years (SD 0.6). Five primary themes regarding the card game emerged: 1) Safe space to disclose personal issues 2) Seeing the world through different views 3) Surprise elements 4) Death distant closure 5) Changed behaviour. Conclusions: Life Unlocking Card Game proves to be an effective tool to teach death and dying issues and also ACP in second year medical students. Further study in clinical year students or postgraduate students are recommended.