Creating believable agents with personality is a popular research area in game studies but academic research in this area usually focuses on one facet of personality - for example, only on moods or character traits. The present study proposes a motivational framework to predict goal-directed behaviour of virtual agents in a computer game and explores the opportunities of using personality inventories based on the same motivational framework to design virtual agents with personality. This article claims that motivation to reach a goal is influenced by psychological needs which are represented with an equation that determines the strength of a character's motivational force. The framework represented by this study takes into account psychological needs and their interrelations for analyzing choices of virtual agents in a computer game.