Single Player Roleplaying Game (SPRPG) is a popular genre among players as well as developers, with recent blockbuster titles such as Skyrim by Bethesda and Mass E↵ect 3 by Bioware. In recent years, an occurrence that have been gaining a lot of attention is the development of more advanced and vivid Artiﬁcial Intelligence (AI) within these SPRPG and a lot of progress has been made towards making the Non-player Character (NPC) more vivacious and life-like. It is, however, still a common occurrence that NPCs wait around for the player to interact with them; never having a plan or agenda of their own. Their purpose seem to be to wait for the player and provide him or her with information, bartering or a quest. This could result in a game environment that feels static and lifeless to some players and, thus, possibly become detrimental to the game experience. The main objective of this thesis was to implement a need-based system, resembling, to some degree, the one used in The Sims by Maxis, where NPCs get hungry, thirsty, sleepy and similar, and to test whether this system will enhance the game experience. If the NPCs of a SPRPG have needs of their own and therefore can not just wait around for the player to come to them, it may make the game experience more life-like and dynamic. A need-based system that allows the designer to deﬁne a set of needs for each NPC, was implemented using the Aurora Toolset for Neverwinter Nights by Bioware. The system was then tested by allowing a number of people play a custom module for Neverwinter Nights twice: once with the system in place and once without, then answering questionnaires regarding their experience. The results show, unanimously, that this prototype did enhance the game experience. Though this was a small module and only a prototype, it does indicates that the use of a need-based system might indeed enhance the dynamic and vivacity of a SPRPG.