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. / Singleplayer-rollspel är en populär genre bland såväl spelare som utvecklare, med stora titlar såsom Skyrim av Bethesda och Mass Effect 3 av Bioware. På senare tid har utvcklandet av levande och avancerad AI erhållit mycket fokus inom denna typ av spel och stora framsteg har tagits vad gäller att skapa levnadslika och realistiska icke-spelarkaraktärer. Det är dock fortfarande en vanlig förekomst att ickespelarkaraktärer i denna typ av spel saknar en egen agenda eller plan och därför endast står och väntar på att spelaren ska interagera med dem. Denna uppsats har syftat till att implementera ett behovsbaserat system som till viss del liknar det som används i The Sims av Maxis, där icke-spelarkaraktärer blir hungriga, trötta och liknande, och att testa huruvida detta system förhöjer spelupplevelsen. Systemet har implementerats med hjälp av Aurora Toolset till Neverwinter Nights av Bioware och har testats av ett antal personer i en egenskapad modul till spelet. Resultatet har visat, entydigt, att implementationen av detta behovsbaserade system förhöjde spelupplevelsen. Även om systemet, i denna version, är en prototyp, ger det en indikation på att användandet av ett behovsbaserat system kan förhöja spelupplvelsen i ett singeplayer-rollspel.