This thesis investigates the core elements that create a living world in RPG narrative-based games. A comprehensive literature review identifies key components grouped into categories such as “Geography and Vegetation,” “Effects,” “NPC Visual Attributes,” “NPC Relationship & Routines,” and “NPC Culture and Tribes”. A model is created, and this can help as a starting point for developers who want to create a living world in their game. Using case studies from Red Dead Redemption 2 (2018) and Fallout76 (2018), the study examines how these elements contribute to the realism and interactivity of game worlds. Cronbach's Alphareliability measure was used to assess the consistency and authenticity of these elements from multiple raters perspectives. The findings reveal the complexities of creating believable virtual worlds and the varying degrees of agreement among raters. This research enhances the understanding of game design and development, offering insights into crafting immersive and engaging environments. The thesis underscores the importance of detailed environmental and cultural design in developing dynamic and interactive game worlds that enhance player immersion and narrative depth.