Challenging Models: Formalizing Quests in Gamified Systems for Behavioral Change

Tasks performed by users in exchange for some reward, also known as quests or challenges, are one of the essential elements found in gamified systems, including systems for behavioral change. These elements can be tailored to specific players, according to their profile features and past performance, in order to deliver a more personalized and motivating experience. However, in order to automatically generate challenges, a formal, generalizable model of the essential building blocks of such game elements and their internal relations is needed. Although some work has been carried out in the past to define quests and challenges, a widely agreed-upon definition is still missing. Such an abstract definition should be employable across different application domains and scenarios and be flexible with respect to implementation details and human factors. In this work, we employ a model-driven approach to (1) propose a formal definition of quests and challenges in gamified systems, focusing on systems for behavioral change in the mobility domain, (2) model quests by means of a Domain-Specific Language implementing the proposed definition, and (3) take the first steps towards automatic rule generation by demonstrating a mapping between our model and Drools syntax compatible with an existing gamification engine. In particular, we illustrate how to ease the implementation of quests and challenges by using an example from an existing gamified system in the sustainable mobility domain.