Many video games use non-playable characters (NPCs) as important plot devices and for supplying the players with a meaningful playing experience. The Mass Effect series is known to have many likeable NPCs in its story, and even though emotional attachment and believable traits of NPCs has been defined, it is not entirely known what likeable NPCs excel in. Therefore, six participants were interviewed to talk about their favourite and least liked NPC and most memorable moment from the series. The results show that well developed AI, an unique personality, character development and free choice to avoid the NPC made them likeable.

The goal of this thesis is to find out how non-playable characters (NPC) in their own peripheral way, contribute to the narrative and worldbuilding of a video game. A prototype of a role-playing video game (RPG) was created for this particular study, in order to investigate and measure the effect of NPCs on worldbuilding and narrative in video games. Participants were recruited for the testing of the prototype followed by semi-structured interviews. The interviews were then analyzed and a conclusion on how NPCs affect the narrative and worldbuilding was reached, that being through multiple fronts such as foreshadowing future events and giving the world life with culture, and personal identities. / Målet med denna studie är att ta reda på hur icke-spelbara karaktärer (NPC) på sitt eget underordnade, sätt bidrar till narrativet och världsbyggandet av ett videospel. En prototyp av ett digitalt rollspel (RPG) skapades för just denna studie, för att undersöka och mäta effekten som NPCer kan ha på världsbyggnaden och narrativet i ett videospel.   Deltagare rekryterades för testning av prototypen följt av semistrukturerade intervjuer. Intervjuerna analyserades sedan och en slutsats om hur NPCer påverkar narrativ och världsbyggnad nåddes, att det påverkas inom områden liksom att förebåda framtida händelser och tillföra liv i världen med kultur och personliga identiteter.